optimize: field.ReflectValueOf (#7530)

* fix(schema): Check the callback function parameter type

* fix log

* fix

.github/dependabot.yml

@@ -0,0 +1,15 @@
+---
+version: 2
+updates:
+  - package-ecosystem: gomod
+    directory: /
+    schedule:
+      interval: weekly
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+  - package-ecosystem: gomod
+    directory: /tests
+    schedule:
+      interval: weekly

.github/release-drafter.yml

@@ -0,0 +1,20 @@
+name-template: 'v Release $NEXT_PATCH_VERSION 🌈'
+tag-template: 'v$NEXT_PATCH_VERSION'
+categories:
+  - title: '🚀 Features'
+    labels:
+      - 'feature'
+      - 'enhancement'
+  - title: '🐛 Bug Fixes'
+    labels:
+      - 'fix'
+      - 'bugfix'
+      - 'bug'
+  - title: '🧰 Maintenance'
+    label: 'chore'
+change-template: '- $TITLE @$AUTHOR (#$NUMBER)'
+change-title-escapes: '\<*_&'
+template: |
+  ## Changes
+
+  $CHANGES

.github/workflows/create-release.yml

@@ -0,0 +1,31 @@
+name: Create Release
+
+on:
+  push:
+    tags:
+      - 'v*.*.*'
+
+permissions:
+  contents: write
+  pull-requests: read
+
+jobs:
+  create_release:
+    name: Create Release
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Generate Release Notes and Publish
+        id: generate_release_notes
+        uses: release-drafter/release-drafter@v6
+        with:
+          config-name: 'release-drafter.yml'
+          name: "Release ${{ github.ref_name }}"
+          tag: ${{ github.ref_name }}
+          publish: true
+          prerelease: false
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/golangci-lint.yml

@@ -0,0 +1,26 @@
+name: golangci-lint
+on:
+  push:
+    branches:
+      - main
+      - master
+  pull_request:
+
+permissions:
+  contents: read
+  pull-requests: read
+
+jobs:
+  golangci:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: stable
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v7
+        with:
+          version: v2.0
+          only-new-issues: true

.github/workflows/invalid_question.yml

@@ -3,20 +3,26 @@ on:
   schedule:
   - cron: "*/10 * * * *"
 
+permissions:
+  contents: read
+
 jobs:
   stale:
+    permissions:
+      issues: write  # for actions/stale to close stale issues
+      pull-requests: write  # for actions/stale to close stale PRs
     runs-on: ubuntu-latest
     env:
       ACTIONS_STEP_DEBUG: true
     steps:
     - name: Close Stale Issues
-      uses: actions/stale@v3.0.7
+      uses: actions/stale@v8
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
-        stale-issue-message: "This issue has been marked as invalid question, please give more information by following the `Question` template, if you believe there is a bug of GORM, please create a pull request that could reproduce the issue on [https://github.com/go-gorm/playground](https://github.com/go-gorm/playground), the issue will be closed in 2 days if no further activity occurs. most likely your question already answered https://github.com/go-gorm/gorm/issues or described in the document https://gorm.io ✨ [Search Before Asking](https://stackoverflow.com/help/how-to-ask) ✨"
+        stale-issue-message: "This issue has been marked as invalid question, please give more information by following the `Question` template, if you believe there is a bug of GORM, please create a pull request that could reproduce the issue on [https://github.com/go-gorm/playground](https://github.com/go-gorm/playground), the issue will be closed in 30 days if no further activity occurs. most likely your question already answered https://github.com/go-gorm/gorm/issues or described in the document https://gorm.io ✨ [Search Before Asking](https://stackoverflow.com/help/how-to-ask) ✨"
         stale-issue-label: "status:stale"
         days-before-stale: 0
-        days-before-close: 2
+        days-before-close: 30
         remove-stale-when-updated: true
         only-labels: "type:invalid question"
 

.github/workflows/labeler.yml

@@ -11,7 +11,7 @@ jobs:
     name: Label issues and pull requests
     steps:
       - name: check out
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: labeler
         uses: jinzhu/super-labeler-action@develop

.github/workflows/missing_playground.yml

@@ -3,19 +3,25 @@ on:
   schedule:
   - cron: "*/10 * * * *"
 
+permissions:
+  contents: read
+
 jobs:
   stale:
+    permissions:
+      issues: write  # for actions/stale to close stale issues
+      pull-requests: write  # for actions/stale to close stale PRs
     runs-on: ubuntu-latest
     env:
       ACTIONS_STEP_DEBUG: true
     steps:
     - name: Close Stale Issues
-      uses: actions/stale@v3.0.7
+      uses: actions/stale@v8
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
-        stale-issue-message: "The issue has been automatically marked as stale as it missing playground pull request link, which is important to help others understand your issue effectively and make sure the issue hasn't been fixed on latest master, checkout [https://github.com/go-gorm/playground](https://github.com/go-gorm/playground) for details. it will be closed in 2 days if no further activity occurs. if you are asking question, please use the `Question` template, most likely your question already answered https://github.com/go-gorm/gorm/issues or described in the document https://gorm.io ✨ [Search Before Asking](https://stackoverflow.com/help/how-to-ask) ✨"
+        stale-issue-message: "The issue has been automatically marked as stale as it missing playground pull request link, which is important to help others understand your issue effectively and make sure the issue hasn't been fixed on latest master, checkout [https://github.com/go-gorm/playground](https://github.com/go-gorm/playground) for details. it will be closed in 30 days if no further activity occurs. if you are asking question, please use the `Question` template, most likely your question already answered https://github.com/go-gorm/gorm/issues or described in the document https://gorm.io ✨ [Search Before Asking](https://stackoverflow.com/help/how-to-ask) ✨"
         stale-issue-label: "status:stale"
         days-before-stale: 0
-        days-before-close: 2
+        days-before-close: 30
         remove-stale-when-updated: true
         only-labels: "type:missing reproduction steps"

.github/workflows/reviewdog.yml

@@ -1,11 +0,0 @@
-name: reviewdog
-on: [pull_request]
-jobs:
-  golangci-lint:
-    name: runner / golangci-lint
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check out code into the Go module directory
-        uses: actions/checkout@v1
-      - name: golangci-lint
-        uses: reviewdog/action-golangci-lint@v1

.github/workflows/stale.yml

@@ -3,19 +3,25 @@ on:
   schedule:
   - cron: "0 2 * * *"
 
+permissions:
+  contents: read
+
 jobs:
   stale:
+    permissions:
+      issues: write  # for actions/stale to close stale issues
+      pull-requests: write  # for actions/stale to close stale PRs
     runs-on: ubuntu-latest
     env:
       ACTIONS_STEP_DEBUG: true
     steps:
     - name: Close Stale Issues
-      uses: actions/stale@v3.0.7
+      uses: actions/stale@v8
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
-        stale-issue-message: "This issue has been automatically marked as stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 30 days"
-        days-before-stale: 60
-        days-before-close: 30
+        stale-issue-message: "This issue has been automatically marked as stale because it has been open 360 days with no activity. Remove stale label or comment or this will be closed in 180 days"
+        days-before-stale: 360
+        days-before-close: 180
         stale-issue-label: "status:stale"
         exempt-issue-labels: 'type:feature,type:with reproduction steps,type:has pull request'
         stale-pr-label: 'status:stale'

.github/workflows/tests.yml

@@ -8,63 +8,41 @@ on:
     branches-ignore:
       - 'gh-pages'
 
+permissions:
+  contents: read
+
 jobs:
   # Label of the container job
   sqlite:
     strategy:
       matrix:
-        go: ['1.15', '1.14', '1.13']
-        platform: [ubuntu-latest, macos-latest] # can not run in windows OS
+        go: ['1.23', '1.24']
+        platform: [ubuntu-latest] # can not run in windows OS
     runs-on: ${{ matrix.platform }}
 
     steps:
     - name: Set up Go 1.x
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v4
       with:
         go-version: ${{ matrix.go }}
 
     - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
     - name: go mod package cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
 
     - name: Tests
-      run: GORM_DIALECT=sqlite ./tests/tests_all.sh
-
-  sqlite_windows:
-    strategy:
-      matrix:
-        go: ['1.15', '1.14', '1.13']
-        platform: [windows-latest]
-    runs-on: ${{ matrix.platform }}
-
-    steps:
-    - name: Set up Go 1.x
-      uses: actions/setup-go@v2
-      with:
-        go-version: ${{ matrix.go }}
-
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
-
-    - name: go mod package cache
-      uses: actions/cache@v2
-      with:
-        path: ~/go/pkg/mod
-        key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
-
-    - name: Tests
-      run: cd tests && set GORM_DIALECT=sqlite && go test $race -count=1 -v ./... #run the line in widnows's CMD, default GORM_DIALECT is sqlite
+      run: GITHUB_ACTION=true GORM_DIALECT=sqlite ./tests/tests_all.sh
 
   mysql:
     strategy:
       matrix:
-        dbversion: ['mysql:latest', 'mysql:5.7', 'mysql:5.6', 'mariadb:latest']
-        go: ['1.15', '1.14', '1.13']
+        dbversion: ['mysql:9', 'mysql:8', 'mysql:5.7']
+        go: ['1.23', '1.24']
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
 
@@ -87,29 +65,71 @@ jobs:
 
     steps:
     - name: Set up Go 1.x
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v4
       with:
         go-version: ${{ matrix.go }}
 
     - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
-
+      uses: actions/checkout@v4
 
     - name: go mod package cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
 
     - name: Tests
-      run: GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True" ./tests/tests_all.sh
+      run: GITHUB_ACTION=true GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True" ./tests/tests_all.sh
+
+  mariadb:
+    strategy:
+      matrix:
+        dbversion: [ 'mariadb:latest' ]
+        go: ['1.23', '1.24']
+        platform: [ ubuntu-latest ]
+    runs-on: ${{ matrix.platform }}
+
+    services:
+      mysql:
+        image: ${{ matrix.dbversion }}
+        env:
+          MYSQL_DATABASE: gorm
+          MYSQL_USER: gorm
+          MYSQL_PASSWORD: gorm
+          MYSQL_RANDOM_ROOT_PASSWORD: "yes"
+        ports:
+          - 9910:3306
+        options: >-
+          --health-cmd "mariadb-admin ping -ugorm -pgorm"
+          --health-interval 10s
+          --health-start-period 10s
+          --health-timeout 5s
+          --health-retries 10
+
+    steps:
+      - name: Set up Go 1.x
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ matrix.go }}
+
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v4
+
+      - name: go mod package cache
+        uses: actions/cache@v4
+        with:
+          path: ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
+
+      - name: Tests
+        run: GITHUB_ACTION=true GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True" ./tests/tests_all.sh
 
   postgres:
     strategy:
       matrix:
-        dbversion: ['postgres:latest', 'postgres:11', 'postgres:10']
-        go: ['1.15', '1.14', '1.13']
-        platform: [ubuntu-latest] # can not run in macOS and widnowsOS
+        dbversion: ['postgres:latest', 'postgres:15', 'postgres:14', 'postgres:13']
+        go: ['1.23', '1.24']
+        platform: [ubuntu-latest] # can not run in macOS and Windows
     runs-on: ${{ matrix.platform }}
 
     services:
@@ -131,42 +151,40 @@ jobs:
 
     steps:
     - name: Set up Go 1.x
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v4
       with:
         go-version: ${{ matrix.go }}
 
     - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
     - name: go mod package cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
 
     - name: Tests
-      run: GORM_DIALECT=postgres GORM_DSN="user=gorm password=gorm dbname=gorm host=localhost port=9920 sslmode=disable TimeZone=Asia/Shanghai" ./tests/tests_all.sh
+      run: GITHUB_ACTION=true GORM_DIALECT=postgres GORM_DSN="user=gorm password=gorm dbname=gorm host=localhost port=9920 sslmode=disable TimeZone=Asia/Shanghai" ./tests/tests_all.sh
 
   sqlserver:
     strategy:
       matrix:
-        go: ['1.15', '1.14', '1.13']
+        go: ['1.23', '1.24']
         platform: [ubuntu-latest] # can not run test in macOS and windows
     runs-on: ${{ matrix.platform }}
 
     services:
       mssql:
-        image: mcmoe/mssqldocker:latest
+        image: mcr.microsoft.com/mssql/server:2022-latest
         env:
+          TZ: Asia/Shanghai
           ACCEPT_EULA: Y
-          SA_PASSWORD: LoremIpsum86
-          MSSQL_DB: gorm
-          MSSQL_USER: gorm
-          MSSQL_PASSWORD: LoremIpsum86
+          MSSQL_SA_PASSWORD: LoremIpsum86
         ports:
           - 9930:1433
         options: >-
-          --health-cmd="/opt/mssql-tools/bin/sqlcmd -S localhost -U sa -P LoremIpsum86 -l 30 -Q \"SELECT 1\" || exit 1"
+          --health-cmd="/opt/mssql-tools18/bin/sqlcmd -S localhost -U sa -P ${MSSQL_SA_PASSWORD} -N -C -l 30 -Q \"SELECT 1\" || exit 1"
           --health-start-period 10s
           --health-interval 10s
           --health-timeout 5s
@@ -174,18 +192,119 @@ jobs:
 
     steps:
     - name: Set up Go 1.x
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v4
       with:
         go-version: ${{ matrix.go }}
 
     - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
     - name: go mod package cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
 
     - name: Tests
-      run: GORM_DIALECT=sqlserver GORM_DSN="sqlserver://gorm:LoremIpsum86@localhost:9930?database=gorm" ./tests/tests_all.sh
+      run: GITHUB_ACTION=true GORM_DIALECT=sqlserver GORM_DSN="sqlserver://sa:LoremIpsum86@localhost:9930?database=master" ./tests/tests_all.sh
+
+  tidb:
+    strategy:
+      matrix:
+        dbversion: [ 'v6.5.0' ]
+        go: ['1.23', '1.24']
+        platform: [ ubuntu-latest ]
+    runs-on: ${{ matrix.platform }}
+
+    steps:
+      - name: Setup TiDB
+        uses: Icemap/tidb-action@main
+        with:
+          port: 9940
+          version: ${{matrix.dbversion}}
+
+      - name: Set up Go 1.x
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ matrix.go }}
+
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v4
+
+
+      - name: go mod package cache
+        uses: actions/cache@v4
+        with:
+          path: ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
+
+      - name: Tests
+        run: GITHUB_ACTION=true GORM_DIALECT=tidb GORM_DSN="root:@tcp(localhost:9940)/test?charset=utf8&parseTime=True&loc=Local" ./tests/tests_all.sh
+
+  gaussdb:
+    strategy:
+      matrix:
+        dbversion: ['opengauss/opengauss:7.0.0-RC1.B023']
+        go: ['1.23', '1.24']
+        platform: [ubuntu-latest] # can not run in macOS and Windows
+    runs-on: ${{ matrix.platform }}
+
+    services:
+      gaussdb:
+        image: ${{ matrix.dbversion }}
+        env:
+          # GaussDB has password limitations
+          GS_PASSWORD: Gaussdb@123
+          TZ: Asia/Shanghai
+        ports:
+          - 9950:5432
+
+    steps:
+      - name: Set up Go 1.x
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ matrix.go }}
+
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v4
+
+      - name: Waiting for GaussDB to be ready
+        run: |
+          container_name=$(docker ps --filter "ancestor=opengauss/opengauss:7.0.0-RC1.B023" --format "{{.Names}}")
+          if [ -z "$container_name" ]; then
+            echo "Error: failed to find a container created from the 'opengauss/opengauss:7.0.0-RC1.B023' image."
+            exit 1
+          fi
+          max_retries=12
+          retry_count=0
+          if [ -t 0 ]; then
+            TTY_FLAG="-t"
+          else
+            TTY_FLAG=""
+          fi
+          while [ $retry_count -lt $max_retries ]; do
+            if docker exec -i "${container_name}" bash -c "su - omm -c 'gsql -U omm -c \"select 1;\"'" 
+            then
+              echo "Creating database gorm..."
+              sql_file='/tmp/create_database.sql'
+              echo "CREATE DATABASE gorm DBCOMPATIBILITY 'PG';" > ${sql_file}
+              docker cp "${sql_file}" "${container_name}":"${sql_file}"
+              docker exec -i ${TTY_FLAG} "${container_name}" bash -c "su - omm -c 'gsql -U omm -f ${sql_file}'"
+              echo "Database initialization completed."
+              break
+            fi
+
+            echo "Waiting for database to be ready... (attempt $((retry_count + 1))/$max_retries)"
+            sleep 10
+            ((++retry_count))
+          done
+          exit 0
+
+      - name: go mod package cache
+        uses: actions/cache@v4
+        with:
+          path: ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
+
+      - name: Tests
+        run: GITHUB_ACTION=true GORM_DIALECT=gaussdb GORM_DSN="user=gaussdb password=Gaussdb@123 dbname=gorm host=localhost port=9950 sslmode=disable TimeZone=Asia/Shanghai" ./tests/tests_all.sh

.gitignore

@@ -3,3 +3,5 @@ documents
 coverage.txt
 _book
 .idea
+vendor
+.vscode

.golangci.yml

@@ -0,0 +1,19 @@
+version: "2"
+
+linters:
+  default: standard
+  enable:
+    - cyclop
+    - gocritic
+    - gosec
+    - ineffassign
+    - misspell
+    - prealloc
+    - unconvert
+    - unparam
+    - whitespace
+
+formatters:
+  enable:
+    - gofumpt
+    - goimports

CODE_OF_CONDUCT.md

@@ -0,0 +1,128 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to participate in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, religion, or sexual identity
+and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community includes:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the
+  overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or
+  advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email
+  address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement at
+.
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series
+of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period. This
+includes avoiding interactions in community spaces and external channels
+like social media. Violating these terms may lead to a temporary or
+permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any interaction or public
+communication with the community for a specified period. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior,  harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within
+the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.0, available at
+https://www.contributor-covenant.org/version/2/0/code_of_conduct.html.
+
+Community Impact Guidelines were inspired by [Mozilla's code of conduct
+enforcement ladder](https://github.com/mozilla/diversity).
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see the FAQ at
+https://www.contributor-covenant.org/faq. Translations are available at
+https://www.contributor-covenant.org/translations.

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2013-NOW  Jinzhu <wosmvp@gmail.com>
+Copyright (c) 2013-present  Jinzhu <wosmvp@gmail.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -4,9 +4,6 @@ The fantastic ORM library for Golang, aims to be developer friendly.
 
 [![go report card](https://goreportcard.com/badge/github.com/go-gorm/gorm "go report card")](https://goreportcard.com/report/github.com/go-gorm/gorm)
 [![test status](https://github.com/go-gorm/gorm/workflows/tests/badge.svg?branch=master "test status")](https://github.com/go-gorm/gorm/actions)
-[![Join the chat at https://gitter.im/jinzhu/gorm](https://img.shields.io/gitter/room/jinzhu/gorm.svg)](https://gitter.im/jinzhu/gorm?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![Open Collective Backer](https://opencollective.com/gorm/tiers/backer/badge.svg?label=backer&color=brightgreen "Open Collective Backer")](https://opencollective.com/gorm)
-[![Open Collective Sponsor](https://opencollective.com/gorm/tiers/sponsor/badge.svg?label=sponsor&color=brightgreen "Open Collective Sponsor")](https://opencollective.com/gorm)
 [![MIT license](https://img.shields.io/badge/license-MIT-brightgreen.svg)](https://opensource.org/licenses/MIT)
 [![Go.Dev reference](https://img.shields.io/badge/go.dev-reference-blue?logo=go&logoColor=white)](https://pkg.go.dev/gorm.io/gorm?tab=doc)
 
@@ -30,13 +27,18 @@ The fantastic ORM library for Golang, aims to be developer friendly.
 ## Getting Started
 
 * GORM Guides [https://gorm.io](https://gorm.io)
+* Gen Guides [https://gorm.io/gen/index.html](https://gorm.io/gen/index.html)
 
 ## Contributing
 
 [You can help to deliver a better GORM, check out things you can do](https://gorm.io/contribute.html)
 
+## Contributors
+
+[Thank you](https://github.com/go-gorm/gorm/graphs/contributors) for contributing to the GORM framework!
+
 ## License
 
 © Jinzhu, 2013~time.Now
 
-Released under the [MIT License](https://github.com/go-gorm/gorm/blob/master/License)
+Released under the [MIT License](https://github.com/go-gorm/gorm/blob/master/LICENSE)

association.go

@@ -14,6 +14,7 @@ import (
 type Association struct {
 	DB           *DB
 	Relationship *schema.Relationship
+	Unscope      bool
 	Error        error
 }
 
@@ -26,7 +27,7 @@ func (db *DB) Association(column string) *Association {
 		association.Relationship = db.Statement.Schema.Relationships.Relations[column]
 
 		if association.Relationship == nil {
-			association.Error = fmt.Errorf("%w: %v", ErrUnsupportedRelation, column)
+			association.Error = fmt.Errorf("%w: %s", ErrUnsupportedRelation, column)
 		}
 
 		db.Statement.ReflectValue = reflect.ValueOf(db.Statement.Model)
@@ -40,6 +41,15 @@ func (db *DB) Association(column string) *Association {
 	return association
 }
 
+func (association *Association) Unscoped() *Association {
+	return &Association{
+		DB:           association.DB,
+		Relationship: association.Relationship,
+		Error:        association.Error,
+		Unscope:      true,
+	}
+}
+
 func (association *Association) Find(out interface{}, conds ...interface{}) error {
 	if association.Error == nil {
 		association.Error = association.buildCondition().Find(out, conds...).Error
@@ -64,14 +74,30 @@ func (association *Association) Append(values ...interface{}) error {
 
 func (association *Association) Replace(values ...interface{}) error {
 	if association.Error == nil {
+		reflectValue := association.DB.Statement.ReflectValue
+		rel := association.Relationship
+
+		var oldBelongsToExpr clause.Expression
+		// we have to record the old BelongsTo value
+		if association.Unscope && rel.Type == schema.BelongsTo {
+			var foreignFields []*schema.Field
+			for _, ref := range rel.References {
+				if !ref.OwnPrimaryKey {
+					foreignFields = append(foreignFields, ref.ForeignKey)
+				}
+			}
+			if _, fvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, reflectValue, foreignFields); len(fvs) > 0 {
+				column, values := schema.ToQueryValues(rel.FieldSchema.Table, rel.FieldSchema.PrimaryFieldDBNames, fvs)
+				oldBelongsToExpr = clause.IN{Column: column, Values: values}
+			}
+		}
+
 		// save associations
 		if association.saveAssociation( /*clear*/ true, values...); association.Error != nil {
 			return association.Error
 		}
 
 		// set old associations's foreign key to null
-		reflectValue := association.DB.Statement.ReflectValue
-		rel := association.Relationship
 		switch rel.Type {
 		case schema.BelongsTo:
 			if len(values) == 0 {
@@ -79,10 +105,10 @@ func (association *Association) Replace(values ...interface{}) error {
 				switch reflectValue.Kind() {
 				case reflect.Slice, reflect.Array:
 					for i := 0; i < reflectValue.Len(); i++ {
-						association.Error = rel.Field.Set(reflectValue.Index(i), reflect.Zero(rel.Field.FieldType).Interface())
+						association.Error = rel.Field.Set(association.DB.Statement.Context, reflectValue.Index(i), reflect.Zero(rel.Field.FieldType).Interface())
 					}
 				case reflect.Struct:
-					association.Error = rel.Field.Set(reflectValue, reflect.Zero(rel.Field.FieldType).Interface())
+					association.Error = rel.Field.Set(association.DB.Statement.Context, reflectValue, reflect.Zero(rel.Field.FieldType).Interface())
 				}
 
 				for _, ref := range rel.References {
@@ -91,17 +117,20 @@ func (association *Association) Replace(values ...interface{}) error {
 
 				association.Error = association.DB.UpdateColumns(updateMap).Error
 			}
+			if association.Unscope && oldBelongsToExpr != nil {
+				association.Error = association.DB.Model(nil).Where(oldBelongsToExpr).Delete(reflect.New(rel.FieldSchema.ModelType).Interface()).Error
+			}
 		case schema.HasOne, schema.HasMany:
 			var (
 				primaryFields []*schema.Field
 				foreignKeys   []string
 				updateMap     = map[string]interface{}{}
-				relValues     = schema.GetRelationsValues(reflectValue, []*schema.Relationship{rel})
+				relValues     = schema.GetRelationsValues(association.DB.Statement.Context, reflectValue, []*schema.Relationship{rel})
 				modelValue    = reflect.New(rel.FieldSchema.ModelType).Interface()
 				tx            = association.DB.Model(modelValue)
 			)
 
-			if _, rvs := schema.GetIdentityFieldValuesMap(relValues, rel.FieldSchema.PrimaryFields); len(rvs) > 0 {
+			if _, rvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, relValues, rel.FieldSchema.PrimaryFields); len(rvs) > 0 {
 				if column, values := schema.ToQueryValues(rel.FieldSchema.Table, rel.FieldSchema.PrimaryFieldDBNames, rvs); len(values) > 0 {
 					tx.Not(clause.IN{Column: column, Values: values})
 				}
@@ -117,9 +146,13 @@ func (association *Association) Replace(values ...interface{}) error {
 				}
 			}
 
-			if _, pvs := schema.GetIdentityFieldValuesMap(reflectValue, primaryFields); len(pvs) > 0 {
+			if _, pvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, reflectValue, primaryFields); len(pvs) > 0 {
 				column, values := schema.ToQueryValues(rel.FieldSchema.Table, foreignKeys, pvs)
-				association.Error = tx.Where(clause.IN{Column: column, Values: values}).UpdateColumns(updateMap).Error
+				if association.Unscope {
+					association.Error = tx.Where(clause.IN{Column: column, Values: values}).Delete(modelValue).Error
+				} else {
+					association.Error = tx.Where(clause.IN{Column: column, Values: values}).UpdateColumns(updateMap).Error
+				}
 			}
 		case schema.Many2Many:
 			var (
@@ -143,14 +176,14 @@ func (association *Association) Replace(values ...interface{}) error {
 				}
 			}
 
-			_, pvs := schema.GetIdentityFieldValuesMap(reflectValue, primaryFields)
+			_, pvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, reflectValue, primaryFields)
 			if column, values := schema.ToQueryValues(rel.JoinTable.Table, joinPrimaryKeys, pvs); len(values) > 0 {
 				tx.Where(clause.IN{Column: column, Values: values})
 			} else {
 				return ErrPrimaryKeyRequired
 			}
 
-			_, rvs := schema.GetIdentityFieldValuesMapFromValues(values, relPrimaryFields)
+			_, rvs := schema.GetIdentityFieldValuesMapFromValues(association.DB.Statement.Context, values, relPrimaryFields)
 			if relColumn, relValues := schema.ToQueryValues(rel.JoinTable.Table, joinRelPrimaryKeys, rvs); len(relValues) > 0 {
 				tx.Where(clause.Not(clause.IN{Column: relColumn, Values: relValues}))
 			}
@@ -184,29 +217,53 @@ func (association *Association) Delete(values ...interface{}) error {
 
 		switch rel.Type {
 		case schema.BelongsTo:
-			tx := association.DB.Model(reflect.New(rel.Schema.ModelType).Interface())
+			associationDB := association.DB.Session(&Session{})
+			tx := associationDB.Model(reflect.New(rel.Schema.ModelType).Interface())
 
-			_, pvs := schema.GetIdentityFieldValuesMap(reflectValue, rel.Schema.PrimaryFields)
-			pcolumn, pvalues := schema.ToQueryValues(rel.Schema.Table, rel.Schema.PrimaryFieldDBNames, pvs)
-			conds = append(conds, clause.IN{Column: pcolumn, Values: pvalues})
+			_, pvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, reflectValue, rel.Schema.PrimaryFields)
+			if pcolumn, pvalues := schema.ToQueryValues(rel.Schema.Table, rel.Schema.PrimaryFieldDBNames, pvs); len(pvalues) > 0 {
+				conds = append(conds, clause.IN{Column: pcolumn, Values: pvalues})
+			} else {
+				return ErrPrimaryKeyRequired
+			}
 
-			_, rvs := schema.GetIdentityFieldValuesMapFromValues(values, primaryFields)
+			_, rvs := schema.GetIdentityFieldValuesMapFromValues(association.DB.Statement.Context, values, primaryFields)
 			relColumn, relValues := schema.ToQueryValues(rel.Schema.Table, foreignKeys, rvs)
 			conds = append(conds, clause.IN{Column: relColumn, Values: relValues})
 
 			association.Error = tx.Clauses(conds...).UpdateColumns(updateAttrs).Error
+			if association.Unscope {
+				var foreignFields []*schema.Field
+				for _, ref := range rel.References {
+					if !ref.OwnPrimaryKey {
+						foreignFields = append(foreignFields, ref.ForeignKey)
+					}
+				}
+				if _, fvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, reflectValue, foreignFields); len(fvs) > 0 {
+					column, values := schema.ToQueryValues(rel.FieldSchema.Table, rel.FieldSchema.PrimaryFieldDBNames, fvs)
+					association.Error = associationDB.Model(nil).Where(clause.IN{Column: column, Values: values}).Delete(reflect.New(rel.FieldSchema.ModelType).Interface()).Error
+				}
+			}
 		case schema.HasOne, schema.HasMany:
-			tx := association.DB.Model(reflect.New(rel.FieldSchema.ModelType).Interface())
+			model := reflect.New(rel.FieldSchema.ModelType).Interface()
+			tx := association.DB.Model(model)
 
-			_, pvs := schema.GetIdentityFieldValuesMap(reflectValue, primaryFields)
-			pcolumn, pvalues := schema.ToQueryValues(rel.FieldSchema.Table, foreignKeys, pvs)
-			conds = append(conds, clause.IN{Column: pcolumn, Values: pvalues})
+			_, pvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, reflectValue, primaryFields)
+			if pcolumn, pvalues := schema.ToQueryValues(rel.FieldSchema.Table, foreignKeys, pvs); len(pvalues) > 0 {
+				conds = append(conds, clause.IN{Column: pcolumn, Values: pvalues})
+			} else {
+				return ErrPrimaryKeyRequired
+			}
 
-			_, rvs := schema.GetIdentityFieldValuesMapFromValues(values, rel.FieldSchema.PrimaryFields)
+			_, rvs := schema.GetIdentityFieldValuesMapFromValues(association.DB.Statement.Context, values, rel.FieldSchema.PrimaryFields)
 			relColumn, relValues := schema.ToQueryValues(rel.FieldSchema.Table, rel.FieldSchema.PrimaryFieldDBNames, rvs)
 			conds = append(conds, clause.IN{Column: relColumn, Values: relValues})
 
-			association.Error = tx.Clauses(conds...).UpdateColumns(updateAttrs).Error
+			if association.Unscope {
+				association.Error = tx.Clauses(conds...).Delete(model).Error
+			} else {
+				association.Error = tx.Clauses(conds...).UpdateColumns(updateAttrs).Error
+			}
 		case schema.Many2Many:
 			var (
 				primaryFields, relPrimaryFields     []*schema.Field
@@ -228,11 +285,14 @@ func (association *Association) Delete(values ...interface{}) error {
 				}
 			}
 
-			_, pvs := schema.GetIdentityFieldValuesMap(reflectValue, primaryFields)
-			pcolumn, pvalues := schema.ToQueryValues(rel.JoinTable.Table, joinPrimaryKeys, pvs)
-			conds = append(conds, clause.IN{Column: pcolumn, Values: pvalues})
+			_, pvs := schema.GetIdentityFieldValuesMap(association.DB.Statement.Context, reflectValue, primaryFields)
+			if pcolumn, pvalues := schema.ToQueryValues(rel.JoinTable.Table, joinPrimaryKeys, pvs); len(pvalues) > 0 {
+				conds = append(conds, clause.IN{Column: pcolumn, Values: pvalues})
+			} else {
+				return ErrPrimaryKeyRequired
+			}
 
-			_, rvs := schema.GetIdentityFieldValuesMapFromValues(values, relPrimaryFields)
+			_, rvs := schema.GetIdentityFieldValuesMapFromValues(association.DB.Statement.Context, values, relPrimaryFields)
 			relColumn, relValues := schema.ToQueryValues(rel.JoinTable.Table, joinRelPrimaryKeys, rvs)
 			conds = append(conds, clause.IN{Column: relColumn, Values: relValues})
 
@@ -241,11 +301,11 @@ func (association *Association) Delete(values ...interface{}) error {
 
 		if association.Error == nil {
 			// clean up deleted values's foreign key
-			relValuesMap, _ := schema.GetIdentityFieldValuesMapFromValues(values, rel.FieldSchema.PrimaryFields)
+			relValuesMap, _ := schema.GetIdentityFieldValuesMapFromValues(association.DB.Statement.Context, values, rel.FieldSchema.PrimaryFields)
 
 			cleanUpDeletedRelations := func(data reflect.Value) {
-				if _, zero := rel.Field.ValueOf(data); !zero {
-					fieldValue := reflect.Indirect(rel.Field.ReflectValueOf(data))
+				if _, zero := rel.Field.ValueOf(association.DB.Statement.Context, data); !zero {
+					fieldValue := reflect.Indirect(rel.Field.ReflectValueOf(association.DB.Statement.Context, data))
 					primaryValues := make([]interface{}, len(rel.FieldSchema.PrimaryFields))
 
 					switch fieldValue.Kind() {
@@ -253,7 +313,7 @@ func (association *Association) Delete(values ...interface{}) error {
 						validFieldValues := reflect.Zero(rel.Field.IndirectFieldType)
 						for i := 0; i < fieldValue.Len(); i++ {
 							for idx, field := range rel.FieldSchema.PrimaryFields {
-								primaryValues[idx], _ = field.ValueOf(fieldValue.Index(i))
+								primaryValues[idx], _ = field.ValueOf(association.DB.Statement.Context, fieldValue.Index(i))
 							}
 
 							if _, ok := relValuesMap[utils.ToStringKey(primaryValues...)]; !ok {
@@ -261,23 +321,23 @@ func (association *Association) Delete(values ...interface{}) error {
 							}
 						}
 
-						association.Error = rel.Field.Set(data, validFieldValues.Interface())
+						association.Error = rel.Field.Set(association.DB.Statement.Context, data, validFieldValues.Interface())
 					case reflect.Struct:
 						for idx, field := range rel.FieldSchema.PrimaryFields {
-							primaryValues[idx], _ = field.ValueOf(fieldValue)
+							primaryValues[idx], _ = field.ValueOf(association.DB.Statement.Context, fieldValue)
 						}
 
 						if _, ok := relValuesMap[utils.ToStringKey(primaryValues...)]; ok {
-							if association.Error = rel.Field.Set(data, reflect.Zero(rel.FieldSchema.ModelType).Interface()); association.Error != nil {
+							if association.Error = rel.Field.Set(association.DB.Statement.Context, data, reflect.Zero(rel.FieldSchema.ModelType).Interface()); association.Error != nil {
 								break
 							}
 
 							if rel.JoinTable == nil {
 								for _, ref := range rel.References {
 									if ref.OwnPrimaryKey || ref.PrimaryValue != "" {
-										association.Error = ref.ForeignKey.Set(fieldValue, reflect.Zero(ref.ForeignKey.FieldType).Interface())
+										association.Error = ref.ForeignKey.Set(association.DB.Statement.Context, fieldValue, reflect.Zero(ref.ForeignKey.FieldType).Interface())
 									} else {
-										association.Error = ref.ForeignKey.Set(data, reflect.Zero(ref.ForeignKey.FieldType).Interface())
+										association.Error = ref.ForeignKey.Set(association.DB.Statement.Context, data, reflect.Zero(ref.ForeignKey.FieldType).Interface())
 									}
 								}
 							}
@@ -329,14 +389,18 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 			switch rv.Kind() {
 			case reflect.Slice, reflect.Array:
 				if rv.Len() > 0 {
-					association.Error = association.Relationship.Field.Set(source, rv.Index(0).Addr().Interface())
+					association.Error = association.Relationship.Field.Set(association.DB.Statement.Context, source, rv.Index(0).Addr().Interface())
 
 					if association.Relationship.Field.FieldType.Kind() == reflect.Struct {
 						assignBacks = append(assignBacks, assignBack{Source: source, Dest: rv.Index(0)})
 					}
 				}
 			case reflect.Struct:
-				association.Error = association.Relationship.Field.Set(source, rv.Addr().Interface())
+				if !rv.CanAddr() {
+					association.Error = ErrInvalidValue
+					return
+				}
+				association.Error = association.Relationship.Field.Set(association.DB.Statement.Context, source, rv.Addr().Interface())
 
 				if association.Relationship.Field.FieldType.Kind() == reflect.Struct {
 					assignBacks = append(assignBacks, assignBack{Source: source, Dest: rv})
@@ -344,9 +408,13 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 			}
 		case schema.HasMany, schema.Many2Many:
 			elemType := association.Relationship.Field.IndirectFieldType.Elem()
-			fieldValue := reflect.Indirect(association.Relationship.Field.ReflectValueOf(source))
+			oldFieldValue := reflect.Indirect(association.Relationship.Field.ReflectValueOf(association.DB.Statement.Context, source))
+			var fieldValue reflect.Value
 			if clear {
-				fieldValue = reflect.New(association.Relationship.Field.IndirectFieldType).Elem()
+				fieldValue = reflect.MakeSlice(oldFieldValue.Type(), 0, oldFieldValue.Cap())
+			} else {
+				fieldValue = reflect.MakeSlice(oldFieldValue.Type(), oldFieldValue.Len(), oldFieldValue.Cap())
+				reflect.Copy(fieldValue, oldFieldValue)
 			}
 
 			appendToFieldValues := func(ev reflect.Value) {
@@ -355,7 +423,7 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 				} else if ev.Type().Elem().AssignableTo(elemType) {
 					fieldValue = reflect.Append(fieldValue, ev.Elem())
 				} else {
-					association.Error = fmt.Errorf("unsupported data type: %v for relation %v", ev.Type(), association.Relationship.Name)
+					association.Error = fmt.Errorf("unsupported data type: %v for relation %s", ev.Type(), association.Relationship.Name)
 				}
 
 				if elemType.Kind() == reflect.Struct {
@@ -369,11 +437,15 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 					appendToFieldValues(reflect.Indirect(rv.Index(i)).Addr())
 				}
 			case reflect.Struct:
+				if !rv.CanAddr() {
+					association.Error = ErrInvalidValue
+					return
+				}
 				appendToFieldValues(rv.Addr())
 			}
 
 			if association.Error == nil {
-				association.Error = association.Relationship.Field.Set(source, fieldValue.Interface())
+				association.Error = association.Relationship.Field.Set(association.DB.Statement.Context, source, fieldValue.Interface())
 			}
 		}
 	}
@@ -421,7 +493,7 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 			// clear old data
 			if clear && len(values) == 0 {
 				for i := 0; i < reflectValue.Len(); i++ {
-					if err := association.Relationship.Field.Set(reflectValue.Index(i), reflect.New(association.Relationship.Field.IndirectFieldType).Interface()); err != nil {
+					if err := association.Relationship.Field.Set(association.DB.Statement.Context, reflectValue.Index(i), reflect.New(association.Relationship.Field.IndirectFieldType).Interface()); err != nil {
 						association.Error = err
 						break
 					}
@@ -429,7 +501,7 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 					if association.Relationship.JoinTable == nil {
 						for _, ref := range association.Relationship.References {
 							if !ref.OwnPrimaryKey && ref.PrimaryValue == "" {
-								if err := ref.ForeignKey.Set(reflectValue.Index(i), reflect.Zero(ref.ForeignKey.FieldType).Interface()); err != nil {
+								if err := ref.ForeignKey.Set(association.DB.Statement.Context, reflectValue.Index(i), reflect.Zero(ref.ForeignKey.FieldType).Interface()); err != nil {
 									association.Error = err
 									break
 								}
@@ -446,6 +518,9 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 
 		for i := 0; i < reflectValue.Len(); i++ {
 			appendToRelations(reflectValue.Index(i), reflect.Indirect(reflect.ValueOf(values[i])), clear)
+			if association.Error != nil {
+				return
+			}
 
 			// TODO support save slice data, sql with case?
 			association.Error = associationDB.Updates(reflectValue.Index(i).Addr().Interface()).Error
@@ -453,12 +528,12 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 	case reflect.Struct:
 		// clear old data
 		if clear && len(values) == 0 {
-			association.Error = association.Relationship.Field.Set(reflectValue, reflect.New(association.Relationship.Field.IndirectFieldType).Interface())
+			association.Error = association.Relationship.Field.Set(association.DB.Statement.Context, reflectValue, reflect.New(association.Relationship.Field.IndirectFieldType).Interface())
 
 			if association.Relationship.JoinTable == nil && association.Error == nil {
 				for _, ref := range association.Relationship.References {
 					if !ref.OwnPrimaryKey && ref.PrimaryValue == "" {
-						association.Error = ref.ForeignKey.Set(reflectValue, reflect.Zero(ref.ForeignKey.FieldType).Interface())
+						association.Error = ref.ForeignKey.Set(association.DB.Statement.Context, reflectValue, reflect.Zero(ref.ForeignKey.FieldType).Interface())
 					}
 				}
 			}
@@ -467,6 +542,9 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 		for idx, value := range values {
 			rv := reflect.Indirect(reflect.ValueOf(value))
 			appendToRelations(reflectValue, rv, clear && idx == 0)
+			if association.Error != nil {
+				return
+			}
 		}
 
 		if len(values) > 0 {
@@ -475,7 +553,7 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 	}
 
 	for _, assignBack := range assignBacks {
-		fieldValue := reflect.Indirect(association.Relationship.Field.ReflectValueOf(assignBack.Source))
+		fieldValue := reflect.Indirect(association.Relationship.Field.ReflectValueOf(association.DB.Statement.Context, assignBack.Source))
 		if assignBack.Index > 0 {
 			reflect.Indirect(assignBack.Dest).Set(fieldValue.Index(assignBack.Index - 1))
 		} else {
@@ -486,19 +564,21 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 
 func (association *Association) buildCondition() *DB {
 	var (
-		queryConds = association.Relationship.ToQueryConditions(association.DB.Statement.ReflectValue)
+		queryConds = association.Relationship.ToQueryConditions(association.DB.Statement.Context, association.DB.Statement.ReflectValue)
 		modelValue = reflect.New(association.Relationship.FieldSchema.ModelType).Interface()
 		tx         = association.DB.Model(modelValue)
 	)
 
 	if association.Relationship.JoinTable != nil {
 		if !tx.Statement.Unscoped && len(association.Relationship.JoinTable.QueryClauses) > 0 {
-			joinStmt := Statement{DB: tx, Schema: association.Relationship.JoinTable, Table: association.Relationship.JoinTable.Table, Clauses: map[string]clause.Clause{}}
+			joinStmt := Statement{DB: tx, Context: tx.Statement.Context, Schema: association.Relationship.JoinTable, Table: association.Relationship.JoinTable.Table, Clauses: map[string]clause.Clause{}}
 			for _, queryClause := range association.Relationship.JoinTable.QueryClauses {
 				joinStmt.AddClause(queryClause)
 			}
 			joinStmt.Build("WHERE")
-			tx.Clauses(clause.Expr{SQL: strings.Replace(joinStmt.SQL.String(), "WHERE ", "", 1), Vars: joinStmt.Vars})
+			if len(joinStmt.SQL.String()) > 0 {
+				tx.Clauses(clause.Expr{SQL: strings.Replace(joinStmt.SQL.String(), "WHERE ", "", 1), Vars: joinStmt.Vars})
+			}
 		}
 
 		tx = tx.Session(&Session{QueryFields: true}).Clauses(clause.From{Joins: []clause.Join{{

callbacks.go

@@ -32,6 +32,7 @@ type callbacks struct {
 
 type processor struct {
 	db        *DB
+	Clauses   []string
 	fns       []func(*DB)
 	callbacks []*callback
 }
@@ -71,21 +72,38 @@ func (cs *callbacks) Raw() *processor {
 	return cs.processors["raw"]
 }
 
-func (p *processor) Execute(db *DB) {
+func (p *processor) Execute(db *DB) *DB {
+	// call scopes
+	for len(db.Statement.scopes) > 0 {
+		db = db.executeScopes()
+	}
+
 	var (
-		curTime = time.Now()
-		stmt    = db.Statement
+		curTime           = time.Now()
+		stmt              = db.Statement
+		resetBuildClauses bool
 	)
 
+	if len(stmt.BuildClauses) == 0 {
+		stmt.BuildClauses = p.Clauses
+		resetBuildClauses = true
+	}
+
+	if optimizer, ok := db.Statement.Dest.(StatementModifier); ok {
+		optimizer.ModifyStatement(stmt)
+	}
+
+	// assign model values
 	if stmt.Model == nil {
 		stmt.Model = stmt.Dest
 	} else if stmt.Dest == nil {
 		stmt.Dest = stmt.Model
 	}
 
+	// parse model values
 	if stmt.Model != nil {
-		if err := stmt.Parse(stmt.Model); err != nil && (!errors.Is(err, schema.ErrUnsupportedDataType) || (stmt.Table == "" && stmt.SQL.Len() == 0)) {
-			if errors.Is(err, schema.ErrUnsupportedDataType) && stmt.Table == "" {
+		if err := stmt.Parse(stmt.Model); err != nil && (!errors.Is(err, schema.ErrUnsupportedDataType) || (stmt.Table == "" && stmt.TableExpr == nil && stmt.SQL.Len() == 0)) {
+			if errors.Is(err, schema.ErrUnsupportedDataType) && stmt.Table == "" && stmt.TableExpr == nil {
 				db.AddError(fmt.Errorf("%w: Table not set, please set it like: db.Model(&user) or db.Table(\"users\")", err))
 			} else {
 				db.AddError(err)
@@ -93,12 +111,12 @@ func (p *processor) Execute(db *DB) {
 		}
 	}
 
+	// assign stmt.ReflectValue
 	if stmt.Dest != nil {
 		stmt.ReflectValue = reflect.ValueOf(stmt.Dest)
 		for stmt.ReflectValue.Kind() == reflect.Ptr {
 			if stmt.ReflectValue.IsNil() && stmt.ReflectValue.CanAddr() {
 				stmt.ReflectValue.Set(reflect.New(stmt.ReflectValue.Type().Elem()))
-				break
 			}
 
 			stmt.ReflectValue = stmt.ReflectValue.Elem()
@@ -108,27 +126,30 @@ func (p *processor) Execute(db *DB) {
 		}
 	}
 
-	// call scopes
-	for len(stmt.scopes) > 0 {
-		scopes := stmt.scopes
-		stmt.scopes = nil
-		for _, scope := range scopes {
-			db = scope(db)
-		}
-	}
-
 	for _, f := range p.fns {
 		f(db)
 	}
 
-	db.Logger.Trace(stmt.Context, curTime, func() (string, int64) {
-		return db.Dialector.Explain(stmt.SQL.String(), stmt.Vars...), db.RowsAffected
-	}, db.Error)
+	if stmt.SQL.Len() > 0 {
+		db.Logger.Trace(stmt.Context, curTime, func() (string, int64) {
+			sql, vars := stmt.SQL.String(), stmt.Vars
+			if filter, ok := db.Logger.(ParamsFilter); ok {
+				sql, vars = filter.ParamsFilter(stmt.Context, stmt.SQL.String(), stmt.Vars...)
+			}
+			return db.Dialector.Explain(sql, vars...), db.RowsAffected
+		}, db.Error)
+	}
 
 	if !stmt.DB.DryRun {
 		stmt.SQL.Reset()
 		stmt.Vars = nil
 	}
+
+	if resetBuildClauses {
+		stmt.BuildClauses = nil
+	}
+
+	return db
 }
 
 func (p *processor) Get(name string) func(*DB) {
@@ -166,10 +187,18 @@ func (p *processor) Replace(name string, fn func(*DB)) error {
 
 func (p *processor) compile() (err error) {
 	var callbacks []*callback
+	removedMap := map[string]bool{}
 	for _, callback := range p.callbacks {
 		if callback.match == nil || callback.match(p.db) {
 			callbacks = append(callbacks, callback)
 		}
+		if callback.remove {
+			removedMap[callback.name] = true
+		}
+	}
+
+	if len(removedMap) > 0 {
+		callbacks = removeCallbacks(callbacks, removedMap)
 	}
 	p.callbacks = callbacks
 
@@ -197,7 +226,7 @@ func (c *callback) Register(name string, fn func(*DB)) error {
 }
 
 func (c *callback) Remove(name string) error {
-	c.processor.db.Logger.Warn(context.Background(), "removing callback `%v` from %v\n", name, utils.FileWithLineNum())
+	c.processor.db.Logger.Warn(context.Background(), "removing callback `%s` from %s\n", name, utils.FileWithLineNum())
 	c.name = name
 	c.remove = true
 	c.processor.callbacks = append(c.processor.callbacks, c)
@@ -205,7 +234,7 @@ func (c *callback) Remove(name string) error {
 }
 
 func (c *callback) Replace(name string, fn func(*DB)) error {
-	c.processor.db.Logger.Info(context.Background(), "replacing callback `%v` from %v\n", name, utils.FileWithLineNum())
+	c.processor.db.Logger.Info(context.Background(), "replacing callback `%s` from %s\n", name, utils.FileWithLineNum())
 	c.name = name
 	c.handler = fn
 	c.replace = true
@@ -228,14 +257,20 @@ func sortCallbacks(cs []*callback) (fns []func(*DB), err error) {
 		names, sorted []string
 		sortCallback  func(*callback) error
 	)
-	sort.Slice(cs, func(i, j int) bool {
-		return cs[j].before == "*" || cs[j].after == "*"
+	sort.SliceStable(cs, func(i, j int) bool {
+		if cs[j].before == "*" && cs[i].before != "*" {
+			return true
+		}
+		if cs[j].after == "*" && cs[i].after != "*" {
+			return true
+		}
+		return false
 	})
 
 	for _, c := range cs {
 		// show warning message the callback name already exists
 		if idx := getRIndex(names, c.name); idx > -1 && !c.replace && !c.remove && !cs[idx].remove {
-			c.processor.db.Logger.Warn(context.Background(), "duplicated callback `%v` from %v\n", c.name, utils.FileWithLineNum())
+			c.processor.db.Logger.Warn(context.Background(), "duplicated callback `%s` from %s\n", c.name, utils.FileWithLineNum())
 		}
 		names = append(names, c.name)
 	}
@@ -251,7 +286,7 @@ func sortCallbacks(cs []*callback) (fns []func(*DB), err error) {
 					// if before callback already sorted, append current callback just after it
 					sorted = append(sorted[:sortedIdx], append([]string{c.name}, sorted[sortedIdx:]...)...)
 				} else if curIdx > sortedIdx {
-					return fmt.Errorf("conflicting callback %v with before %v", c.name, c.before)
+					return fmt.Errorf("conflicting callback %s with before %s", c.name, c.before)
 				}
 			} else if idx := getRIndex(names, c.before); idx != -1 {
 				// if before callback exists
@@ -269,7 +304,7 @@ func sortCallbacks(cs []*callback) (fns []func(*DB), err error) {
 					// if after callback sorted, append current callback to last
 					sorted = append(sorted, c.name)
 				} else if curIdx < sortedIdx {
-					return fmt.Errorf("conflicting callback %v with before %v", c.name, c.after)
+					return fmt.Errorf("conflicting callback %s with before %s", c.name, c.after)
 				}
 			} else if idx := getRIndex(names, c.after); idx != -1 {
 				// if after callback exists but haven't sorted
@@ -312,3 +347,14 @@ func sortCallbacks(cs []*callback) (fns []func(*DB), err error) {
 
 	return
 }
+
+func removeCallbacks(cs []*callback, nameMap map[string]bool) []*callback {
+	callbacks := make([]*callback, 0, len(cs))
+	for _, callback := range cs {
+		if nameMap[callback.name] {
+			continue
+		}
+		callbacks = append(callbacks, callback)
+	}
+	return callbacks
+}

callbacks/associations.go

@@ -7,6 +7,7 @@ import (
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils"
 )
 
 func SaveBeforeAssociations(create bool) func(db *gorm.DB) {
@@ -23,8 +24,8 @@ func SaveBeforeAssociations(create bool) func(db *gorm.DB) {
 				setupReferences := func(obj reflect.Value, elem reflect.Value) {
 					for _, ref := range rel.References {
 						if !ref.OwnPrimaryKey {
-							pv, _ := ref.PrimaryKey.ValueOf(elem)
-							db.AddError(ref.ForeignKey.Set(obj, pv))
+							pv, _ := ref.PrimaryKey.ValueOf(db.Statement.Context, elem)
+							db.AddError(ref.ForeignKey.Set(db.Statement.Context, obj, pv))
 
 							if dest, ok := db.Statement.Dest.(map[string]interface{}); ok {
 								dest[ref.ForeignKey.DBName] = pv
@@ -39,49 +40,64 @@ func SaveBeforeAssociations(create bool) func(db *gorm.DB) {
 				switch db.Statement.ReflectValue.Kind() {
 				case reflect.Slice, reflect.Array:
 					var (
-						objs      = make([]reflect.Value, 0, db.Statement.ReflectValue.Len())
+						rValLen   = db.Statement.ReflectValue.Len()
+						objs      = make([]reflect.Value, 0, rValLen)
 						fieldType = rel.Field.FieldType
 						isPtr     = fieldType.Kind() == reflect.Ptr
 					)
 
 					if !isPtr {
-						fieldType = reflect.PtrTo(fieldType)
+						fieldType = reflect.PointerTo(fieldType)
 					}
 
 					elems := reflect.MakeSlice(reflect.SliceOf(fieldType), 0, 10)
-					for i := 0; i < db.Statement.ReflectValue.Len(); i++ {
+					distinctElems := reflect.MakeSlice(reflect.SliceOf(fieldType), 0, 10)
+					identityMap := map[string]bool{}
+					for i := 0; i < rValLen; i++ {
 						obj := db.Statement.ReflectValue.Index(i)
+						if reflect.Indirect(obj).Kind() != reflect.Struct {
+							break
+						}
+						if _, zero := rel.Field.ValueOf(db.Statement.Context, obj); !zero { // check belongs to relation value
+							rv := rel.Field.ReflectValueOf(db.Statement.Context, obj) // relation reflect value
+							if !isPtr {
+								rv = rv.Addr()
+							}
+							objs = append(objs, obj)
+							elems = reflect.Append(elems, rv)
 
-						if reflect.Indirect(obj).Kind() == reflect.Struct {
-							if _, zero := rel.Field.ValueOf(obj); !zero { // check belongs to relation value
-								rv := rel.Field.ReflectValueOf(obj) // relation reflect value
-								objs = append(objs, obj)
-								if isPtr {
-									elems = reflect.Append(elems, rv)
-								} else {
-									elems = reflect.Append(elems, rv.Addr())
+							relPrimaryValues := make([]interface{}, 0, len(rel.FieldSchema.PrimaryFields))
+							for _, pf := range rel.FieldSchema.PrimaryFields {
+								if pfv, ok := pf.ValueOf(db.Statement.Context, rv); !ok {
+									relPrimaryValues = append(relPrimaryValues, pfv)
 								}
 							}
-						} else {
-							break
+							cacheKey := utils.ToStringKey(relPrimaryValues...)
+							if len(relPrimaryValues) != len(rel.FieldSchema.PrimaryFields) || !identityMap[cacheKey] {
+								if cacheKey != "" { // has primary fields
+									identityMap[cacheKey] = true
+								}
+
+								distinctElems = reflect.Append(distinctElems, rv)
+							}
 						}
 					}
 
 					if elems.Len() > 0 {
-						if saveAssociations(db, rel, elems.Interface(), selectColumns, restricted, nil) == nil {
+						if saveAssociations(db, rel, distinctElems, selectColumns, restricted, nil) == nil {
 							for i := 0; i < elems.Len(); i++ {
 								setupReferences(objs[i], elems.Index(i))
 							}
 						}
 					}
 				case reflect.Struct:
-					if _, zero := rel.Field.ValueOf(db.Statement.ReflectValue); !zero {
-						rv := rel.Field.ReflectValueOf(db.Statement.ReflectValue) // relation reflect value
+					if _, zero := rel.Field.ValueOf(db.Statement.Context, db.Statement.ReflectValue); !zero {
+						rv := rel.Field.ReflectValueOf(db.Statement.Context, db.Statement.ReflectValue) // relation reflect value
 						if rv.Kind() != reflect.Ptr {
 							rv = rv.Addr()
 						}
 
-						if saveAssociations(db, rel, rv.Interface(), selectColumns, restricted, nil) == nil {
+						if saveAssociations(db, rel, rv, selectColumns, restricted, nil) == nil {
 							setupReferences(db.Statement.ReflectValue, rv)
 						}
 					}
@@ -110,7 +126,7 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 					)
 
 					if !isPtr {
-						fieldType = reflect.PtrTo(fieldType)
+						fieldType = reflect.PointerTo(fieldType)
 					}
 
 					elems := reflect.MakeSlice(reflect.SliceOf(fieldType), 0, 10)
@@ -119,18 +135,18 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 						obj := db.Statement.ReflectValue.Index(i)
 
 						if reflect.Indirect(obj).Kind() == reflect.Struct {
-							if _, zero := rel.Field.ValueOf(obj); !zero {
-								rv := rel.Field.ReflectValueOf(obj)
+							if _, zero := rel.Field.ValueOf(db.Statement.Context, obj); !zero {
+								rv := rel.Field.ReflectValueOf(db.Statement.Context, obj)
 								if rv.Kind() != reflect.Ptr {
 									rv = rv.Addr()
 								}
 
 								for _, ref := range rel.References {
 									if ref.OwnPrimaryKey {
-										fv, _ := ref.PrimaryKey.ValueOf(obj)
-										db.AddError(ref.ForeignKey.Set(rv, fv))
+										fv, _ := ref.PrimaryKey.ValueOf(db.Statement.Context, obj)
+										db.AddError(ref.ForeignKey.Set(db.Statement.Context, rv, fv))
 									} else if ref.PrimaryValue != "" {
-										db.AddError(ref.ForeignKey.Set(rv, ref.PrimaryValue))
+										db.AddError(ref.ForeignKey.Set(db.Statement.Context, rv, ref.PrimaryValue))
 									}
 								}
 
@@ -145,11 +161,11 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 							assignmentColumns = append(assignmentColumns, ref.ForeignKey.DBName)
 						}
 
-						saveAssociations(db, rel, elems.Interface(), selectColumns, restricted, assignmentColumns)
+						saveAssociations(db, rel, elems, selectColumns, restricted, assignmentColumns)
 					}
 				case reflect.Struct:
-					if _, zero := rel.Field.ValueOf(db.Statement.ReflectValue); !zero {
-						f := rel.Field.ReflectValueOf(db.Statement.ReflectValue)
+					if _, zero := rel.Field.ValueOf(db.Statement.Context, db.Statement.ReflectValue); !zero {
+						f := rel.Field.ReflectValueOf(db.Statement.Context, db.Statement.ReflectValue)
 						if f.Kind() != reflect.Ptr {
 							f = f.Addr()
 						}
@@ -157,15 +173,15 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 						assignmentColumns := make([]string, 0, len(rel.References))
 						for _, ref := range rel.References {
 							if ref.OwnPrimaryKey {
-								fv, _ := ref.PrimaryKey.ValueOf(db.Statement.ReflectValue)
-								ref.ForeignKey.Set(f, fv)
+								fv, _ := ref.PrimaryKey.ValueOf(db.Statement.Context, db.Statement.ReflectValue)
+								db.AddError(ref.ForeignKey.Set(db.Statement.Context, f, fv))
 							} else if ref.PrimaryValue != "" {
-								ref.ForeignKey.Set(f, ref.PrimaryValue)
+								db.AddError(ref.ForeignKey.Set(db.Statement.Context, f, ref.PrimaryValue))
 							}
 							assignmentColumns = append(assignmentColumns, ref.ForeignKey.DBName)
 						}
 
-						saveAssociations(db, rel, f.Interface(), selectColumns, restricted, assignmentColumns)
+						saveAssociations(db, rel, f, selectColumns, restricted, assignmentColumns)
 					}
 				}
 			}
@@ -179,28 +195,43 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 				fieldType := rel.Field.IndirectFieldType.Elem()
 				isPtr := fieldType.Kind() == reflect.Ptr
 				if !isPtr {
-					fieldType = reflect.PtrTo(fieldType)
+					fieldType = reflect.PointerTo(fieldType)
 				}
 				elems := reflect.MakeSlice(reflect.SliceOf(fieldType), 0, 10)
+				identityMap := map[string]bool{}
 				appendToElems := func(v reflect.Value) {
-					if _, zero := rel.Field.ValueOf(v); !zero {
-						f := reflect.Indirect(rel.Field.ReflectValueOf(v))
+					if _, zero := rel.Field.ValueOf(db.Statement.Context, v); !zero {
+						f := reflect.Indirect(rel.Field.ReflectValueOf(db.Statement.Context, v))
 
 						for i := 0; i < f.Len(); i++ {
 							elem := f.Index(i)
 							for _, ref := range rel.References {
 								if ref.OwnPrimaryKey {
-									pv, _ := ref.PrimaryKey.ValueOf(v)
-									ref.ForeignKey.Set(elem, pv)
+									pv, _ := ref.PrimaryKey.ValueOf(db.Statement.Context, v)
+									db.AddError(ref.ForeignKey.Set(db.Statement.Context, elem, pv))
 								} else if ref.PrimaryValue != "" {
-									ref.ForeignKey.Set(elem, ref.PrimaryValue)
+									db.AddError(ref.ForeignKey.Set(db.Statement.Context, elem, ref.PrimaryValue))
 								}
 							}
 
-							if isPtr {
-								elems = reflect.Append(elems, elem)
-							} else {
-								elems = reflect.Append(elems, elem.Addr())
+							relPrimaryValues := make([]interface{}, 0, len(rel.FieldSchema.PrimaryFields))
+							for _, pf := range rel.FieldSchema.PrimaryFields {
+								if pfv, ok := pf.ValueOf(db.Statement.Context, elem); !ok {
+									relPrimaryValues = append(relPrimaryValues, pfv)
+								}
+							}
+
+							cacheKey := utils.ToStringKey(relPrimaryValues...)
+							if len(relPrimaryValues) != len(rel.FieldSchema.PrimaryFields) || !identityMap[cacheKey] {
+								if cacheKey != "" { // has primary fields
+									identityMap[cacheKey] = true
+								}
+
+								if isPtr {
+									elems = reflect.Append(elems, elem)
+								} else {
+									elems = reflect.Append(elems, elem.Addr())
+								}
 							}
 						}
 					}
@@ -224,7 +255,7 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 						assignmentColumns = append(assignmentColumns, ref.ForeignKey.DBName)
 					}
 
-					saveAssociations(db, rel, elems.Interface(), selectColumns, restricted, assignmentColumns)
+					saveAssociations(db, rel, elems, selectColumns, restricted, assignmentColumns)
 				}
 			}
 
@@ -237,41 +268,57 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 				fieldType := rel.Field.IndirectFieldType.Elem()
 				isPtr := fieldType.Kind() == reflect.Ptr
 				if !isPtr {
-					fieldType = reflect.PtrTo(fieldType)
+					fieldType = reflect.PointerTo(fieldType)
 				}
 				elems := reflect.MakeSlice(reflect.SliceOf(fieldType), 0, 10)
-				joins := reflect.MakeSlice(reflect.SliceOf(reflect.PtrTo(rel.JoinTable.ModelType)), 0, 10)
+				distinctElems := reflect.MakeSlice(reflect.SliceOf(fieldType), 0, 10)
+				joins := reflect.MakeSlice(reflect.SliceOf(reflect.PointerTo(rel.JoinTable.ModelType)), 0, 10)
 				objs := []reflect.Value{}
 
 				appendToJoins := func(obj reflect.Value, elem reflect.Value) {
 					joinValue := reflect.New(rel.JoinTable.ModelType)
 					for _, ref := range rel.References {
 						if ref.OwnPrimaryKey {
-							fv, _ := ref.PrimaryKey.ValueOf(obj)
-							ref.ForeignKey.Set(joinValue, fv)
+							fv, _ := ref.PrimaryKey.ValueOf(db.Statement.Context, obj)
+							db.AddError(ref.ForeignKey.Set(db.Statement.Context, joinValue, fv))
 						} else if ref.PrimaryValue != "" {
-							ref.ForeignKey.Set(joinValue, ref.PrimaryValue)
+							db.AddError(ref.ForeignKey.Set(db.Statement.Context, joinValue, ref.PrimaryValue))
 						} else {
-							fv, _ := ref.PrimaryKey.ValueOf(elem)
-							ref.ForeignKey.Set(joinValue, fv)
+							fv, _ := ref.PrimaryKey.ValueOf(db.Statement.Context, elem)
+							db.AddError(ref.ForeignKey.Set(db.Statement.Context, joinValue, fv))
 						}
 					}
 					joins = reflect.Append(joins, joinValue)
 				}
 
+				identityMap := map[string]bool{}
 				appendToElems := func(v reflect.Value) {
-					if _, zero := rel.Field.ValueOf(v); !zero {
-						f := reflect.Indirect(rel.Field.ReflectValueOf(v))
-
+					if _, zero := rel.Field.ValueOf(db.Statement.Context, v); !zero {
+						f := reflect.Indirect(rel.Field.ReflectValueOf(db.Statement.Context, v))
 						for i := 0; i < f.Len(); i++ {
 							elem := f.Index(i)
-
-							objs = append(objs, v)
-							if isPtr {
-								elems = reflect.Append(elems, elem)
-							} else {
-								elems = reflect.Append(elems, elem.Addr())
+							if !isPtr {
+								elem = elem.Addr()
 							}
+							objs = append(objs, v)
+							elems = reflect.Append(elems, elem)
+
+							relPrimaryValues := make([]interface{}, 0, len(rel.FieldSchema.PrimaryFields))
+							for _, pf := range rel.FieldSchema.PrimaryFields {
+								if pfv, ok := pf.ValueOf(db.Statement.Context, elem); !ok {
+									relPrimaryValues = append(relPrimaryValues, pfv)
+								}
+							}
+
+							cacheKey := utils.ToStringKey(relPrimaryValues...)
+							if len(relPrimaryValues) != len(rel.FieldSchema.PrimaryFields) || !identityMap[cacheKey] {
+								if cacheKey != "" { // has primary fields
+									identityMap[cacheKey] = true
+								}
+
+								distinctElems = reflect.Append(distinctElems, elem)
+							}
+
 						}
 					}
 				}
@@ -288,12 +335,13 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 					appendToElems(db.Statement.ReflectValue)
 				}
 
-				if elems.Len() > 0 {
+				// optimize elems of reflect value length
+				if elemLen := elems.Len(); elemLen > 0 {
 					if v, ok := selectColumns[rel.Name+".*"]; !ok || v {
-						saveAssociations(db, rel, elems.Interface(), selectColumns, restricted, nil)
+						saveAssociations(db, rel, distinctElems, selectColumns, restricted, nil)
 					}
 
-					for i := 0; i < elems.Len(); i++ {
+					for i := 0; i < elemLen; i++ {
 						appendToJoins(objs[i], elems.Index(i))
 					}
 				}
@@ -309,40 +357,35 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 	}
 }
 
-func onConflictOption(stmt *gorm.Statement, s *schema.Schema, selectColumns map[string]bool, restricted bool, defaultUpdatingColumns []string) clause.OnConflict {
-	if stmt.DB.FullSaveAssociations {
-		defaultUpdatingColumns = make([]string, 0, len(s.DBNames))
-		for _, dbName := range s.DBNames {
-			if v, ok := selectColumns[dbName]; (ok && !v) || (!ok && restricted) {
-				continue
-			}
-
-			if !s.LookUpField(dbName).PrimaryKey {
-				defaultUpdatingColumns = append(defaultUpdatingColumns, dbName)
-			}
-		}
-	}
-
-	if len(defaultUpdatingColumns) > 0 {
-		columns := make([]clause.Column, 0, len(s.PrimaryFieldDBNames))
+func onConflictOption(stmt *gorm.Statement, s *schema.Schema, defaultUpdatingColumns []string) (onConflict clause.OnConflict) {
+	if len(defaultUpdatingColumns) > 0 || stmt.DB.FullSaveAssociations {
+		onConflict.Columns = make([]clause.Column, 0, len(s.PrimaryFieldDBNames))
 		for _, dbName := range s.PrimaryFieldDBNames {
-			columns = append(columns, clause.Column{Name: dbName})
+			onConflict.Columns = append(onConflict.Columns, clause.Column{Name: dbName})
 		}
 
-		return clause.OnConflict{
-			Columns:   columns,
-			DoUpdates: clause.AssignmentColumns(defaultUpdatingColumns),
+		onConflict.UpdateAll = stmt.DB.FullSaveAssociations
+		if !onConflict.UpdateAll {
+			onConflict.DoUpdates = clause.AssignmentColumns(defaultUpdatingColumns)
 		}
+	} else {
+		onConflict.DoNothing = true
 	}
 
-	return clause.OnConflict{DoNothing: true}
+	return
 }
 
-func saveAssociations(db *gorm.DB, rel *schema.Relationship, values interface{}, selectColumns map[string]bool, restricted bool, defaultUpdatingColumns []string) error {
+func saveAssociations(db *gorm.DB, rel *schema.Relationship, rValues reflect.Value, selectColumns map[string]bool, restricted bool, defaultUpdatingColumns []string) error {
+	// stop save association loop
+	if checkAssociationsSaved(db, rValues) {
+		return nil
+	}
+
 	var (
 		selects, omits []string
-		onConflict     = onConflictOption(db.Statement, rel.FieldSchema, selectColumns, restricted, defaultUpdatingColumns)
+		onConflict     = onConflictOption(db.Statement, rel.FieldSchema, defaultUpdatingColumns)
 		refName        = rel.Name + "."
+		values         = rValues.Interface()
 	)
 
 	for name, ok := range selectColumns {
@@ -372,7 +415,7 @@ func saveAssociations(db *gorm.DB, rel *schema.Relationship, values interface{},
 	})
 
 	if tx.Statement.FullSaveAssociations {
-		tx = tx.InstanceSet("gorm:update_track_time", true)
+		tx = tx.Set("gorm:update_track_time", true)
 	}
 
 	if len(selects) > 0 {
@@ -387,3 +430,24 @@ func saveAssociations(db *gorm.DB, rel *schema.Relationship, values interface{},
 
 	return db.AddError(tx.Create(values).Error)
 }
+
+// check association values has been saved
+// if values kind is Struct, check it has been saved
+// if values kind is Slice/Array, check all items have been saved
+var visitMapStoreKey = "gorm:saved_association_map"
+
+func checkAssociationsSaved(db *gorm.DB, values reflect.Value) bool {
+	if visit, ok := db.Get(visitMapStoreKey); ok {
+		if v, ok := visit.(*visitMap); ok {
+			if loadOrStoreVisitMap(v, values) {
+				return true
+			}
+		}
+	} else {
+		vistMap := make(visitMap)
+		loadOrStoreVisitMap(&vistMap, values)
+		db.Set(visitMapStoreKey, &vistMap)
+	}
+
+	return false
+}

callbacks/callbacks.go

@@ -4,9 +4,19 @@ import (
 	"gorm.io/gorm"
 )
 
+var (
+	createClauses = []string{"INSERT", "VALUES", "ON CONFLICT"}
+	queryClauses  = []string{"SELECT", "FROM", "WHERE", "GROUP BY", "ORDER BY", "LIMIT", "FOR"}
+	updateClauses = []string{"UPDATE", "SET", "WHERE"}
+	deleteClauses = []string{"DELETE", "FROM", "WHERE"}
+)
+
 type Config struct {
 	LastInsertIDReversed bool
-	WithReturning        bool
+	CreateClauses        []string
+	QueryClauses         []string
+	UpdateClauses        []string
+	DeleteClauses        []string
 }
 
 func RegisterDefaultCallbacks(db *gorm.DB, config *Config) {
@@ -14,6 +24,19 @@ func RegisterDefaultCallbacks(db *gorm.DB, config *Config) {
 		return !db.SkipDefaultTransaction
 	}
 
+	if len(config.CreateClauses) == 0 {
+		config.CreateClauses = createClauses
+	}
+	if len(config.QueryClauses) == 0 {
+		config.QueryClauses = queryClauses
+	}
+	if len(config.DeleteClauses) == 0 {
+		config.DeleteClauses = deleteClauses
+	}
+	if len(config.UpdateClauses) == 0 {
+		config.UpdateClauses = updateClauses
+	}
+
 	createCallback := db.Callback().Create()
 	createCallback.Match(enableTransaction).Register("gorm:begin_transaction", BeginTransaction)
 	createCallback.Register("gorm:before_create", BeforeCreate)
@@ -22,30 +45,39 @@ func RegisterDefaultCallbacks(db *gorm.DB, config *Config) {
 	createCallback.Register("gorm:save_after_associations", SaveAfterAssociations(true))
 	createCallback.Register("gorm:after_create", AfterCreate)
 	createCallback.Match(enableTransaction).Register("gorm:commit_or_rollback_transaction", CommitOrRollbackTransaction)
+	createCallback.Clauses = config.CreateClauses
 
 	queryCallback := db.Callback().Query()
 	queryCallback.Register("gorm:query", Query)
 	queryCallback.Register("gorm:preload", Preload)
 	queryCallback.Register("gorm:after_query", AfterQuery)
+	queryCallback.Clauses = config.QueryClauses
 
 	deleteCallback := db.Callback().Delete()
 	deleteCallback.Match(enableTransaction).Register("gorm:begin_transaction", BeginTransaction)
 	deleteCallback.Register("gorm:before_delete", BeforeDelete)
 	deleteCallback.Register("gorm:delete_before_associations", DeleteBeforeAssociations)
-	deleteCallback.Register("gorm:delete", Delete)
+	deleteCallback.Register("gorm:delete", Delete(config))
 	deleteCallback.Register("gorm:after_delete", AfterDelete)
 	deleteCallback.Match(enableTransaction).Register("gorm:commit_or_rollback_transaction", CommitOrRollbackTransaction)
+	deleteCallback.Clauses = config.DeleteClauses
 
 	updateCallback := db.Callback().Update()
 	updateCallback.Match(enableTransaction).Register("gorm:begin_transaction", BeginTransaction)
 	updateCallback.Register("gorm:setup_reflect_value", SetupUpdateReflectValue)
 	updateCallback.Register("gorm:before_update", BeforeUpdate)
 	updateCallback.Register("gorm:save_before_associations", SaveBeforeAssociations(false))
-	updateCallback.Register("gorm:update", Update)
+	updateCallback.Register("gorm:update", Update(config))
 	updateCallback.Register("gorm:save_after_associations", SaveAfterAssociations(false))
 	updateCallback.Register("gorm:after_update", AfterUpdate)
 	updateCallback.Match(enableTransaction).Register("gorm:commit_or_rollback_transaction", CommitOrRollbackTransaction)
+	updateCallback.Clauses = config.UpdateClauses
 
-	db.Callback().Row().Register("gorm:row", RowQuery)
-	db.Callback().Raw().Register("gorm:raw", RawExec)
+	rowCallback := db.Callback().Row()
+	rowCallback.Register("gorm:row", RowQuery)
+	rowCallback.Clauses = config.QueryClauses
+
+	rawCallback := db.Callback().Raw()
+	rawCallback.Register("gorm:raw", RawExec)
+	rawCallback.Clauses = config.QueryClauses
 }

callbacks/callmethod.go

@@ -13,11 +13,20 @@ func callMethod(db *gorm.DB, fc func(value interface{}, tx *gorm.DB) bool) {
 		case reflect.Slice, reflect.Array:
 			db.Statement.CurDestIndex = 0
 			for i := 0; i < db.Statement.ReflectValue.Len(); i++ {
-				fc(reflect.Indirect(db.Statement.ReflectValue.Index(i)).Addr().Interface(), tx)
+				if value := reflect.Indirect(db.Statement.ReflectValue.Index(i)); value.CanAddr() {
+					fc(value.Addr().Interface(), tx)
+				} else {
+					db.AddError(gorm.ErrInvalidValue)
+					return
+				}
 				db.Statement.CurDestIndex++
 			}
 		case reflect.Struct:
-			fc(db.Statement.ReflectValue.Addr().Interface(), tx)
+			if db.Statement.ReflectValue.CanAddr() {
+				fc(db.Statement.ReflectValue.Addr().Interface(), tx)
+			} else {
+				db.AddError(gorm.ErrInvalidValue)
+			}
 		}
 	}
 }

callbacks/create.go

@@ -3,12 +3,15 @@ package callbacks
 import (
 	"fmt"
 	"reflect"
+	"strings"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils"
 )
 
+// BeforeCreate before create hooks
 func BeforeCreate(db *gorm.DB) {
 	if db.Error == nil && db.Statement.Schema != nil && !db.Statement.SkipHooks && (db.Statement.Schema.BeforeSave || db.Statement.Schema.BeforeCreate) {
 		callMethod(db, func(value interface{}, tx *gorm.DB) (called bool) {
@@ -30,194 +33,206 @@ func BeforeCreate(db *gorm.DB) {
 	}
 }
 
+// Create create hook
 func Create(config *Config) func(db *gorm.DB) {
-	if config.WithReturning {
-		return CreateWithReturning
-	} else {
-		return func(db *gorm.DB) {
-			if db.Error == nil {
-				if db.Statement.Schema != nil && !db.Statement.Unscoped {
-					for _, c := range db.Statement.Schema.CreateClauses {
-						db.Statement.AddClause(c)
-					}
+	supportReturning := utils.Contains(config.CreateClauses, "RETURNING")
+
+	return func(db *gorm.DB) {
+		if db.Error != nil {
+			return
+		}
+
+		if db.Statement.Schema != nil {
+			if !db.Statement.Unscoped {
+				for _, c := range db.Statement.Schema.CreateClauses {
+					db.Statement.AddClause(c)
 				}
+			}
 
-				if db.Statement.SQL.String() == "" {
-					db.Statement.SQL.Grow(180)
-					db.Statement.AddClauseIfNotExists(clause.Insert{})
-					db.Statement.AddClause(ConvertToCreateValues(db.Statement))
-
-					db.Statement.Build("INSERT", "VALUES", "ON CONFLICT")
-				}
-
-				if !db.DryRun && db.Error == nil {
-					result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
-
-					if err == nil {
-						db.RowsAffected, _ = result.RowsAffected()
-
-						if db.RowsAffected > 0 {
-							if db.Statement.Schema != nil && db.Statement.Schema.PrioritizedPrimaryField != nil && db.Statement.Schema.PrioritizedPrimaryField.HasDefaultValue {
-								if insertID, err := result.LastInsertId(); err == nil && insertID > 0 {
-									switch db.Statement.ReflectValue.Kind() {
-									case reflect.Slice, reflect.Array:
-										if config.LastInsertIDReversed {
-											for i := db.Statement.ReflectValue.Len() - 1; i >= 0; i-- {
-												rv := db.Statement.ReflectValue.Index(i)
-												if reflect.Indirect(rv).Kind() != reflect.Struct {
-													break
-												}
-
-												_, isZero := db.Statement.Schema.PrioritizedPrimaryField.ValueOf(rv)
-												if isZero {
-													db.Statement.Schema.PrioritizedPrimaryField.Set(rv, insertID)
-													insertID -= db.Statement.Schema.PrioritizedPrimaryField.AutoIncrementIncrement
-												}
-											}
-										} else {
-											for i := 0; i < db.Statement.ReflectValue.Len(); i++ {
-												rv := db.Statement.ReflectValue.Index(i)
-												if reflect.Indirect(rv).Kind() != reflect.Struct {
-													break
-												}
-
-												if _, isZero := db.Statement.Schema.PrioritizedPrimaryField.ValueOf(rv); isZero {
-													db.Statement.Schema.PrioritizedPrimaryField.Set(rv, insertID)
-													insertID += db.Statement.Schema.PrioritizedPrimaryField.AutoIncrementIncrement
-												}
-											}
-										}
-									case reflect.Struct:
-										if _, isZero := db.Statement.Schema.PrioritizedPrimaryField.ValueOf(db.Statement.ReflectValue); isZero {
-											db.Statement.Schema.PrioritizedPrimaryField.Set(db.Statement.ReflectValue, insertID)
-										}
-									}
-								} else {
-									db.AddError(err)
-								}
-							}
+			if supportReturning && len(db.Statement.Schema.FieldsWithDefaultDBValue) > 0 {
+				if _, ok := db.Statement.Clauses["RETURNING"]; !ok {
+					fromColumns := make([]clause.Column, 0, len(db.Statement.Schema.FieldsWithDefaultDBValue))
+					for _, field := range db.Statement.Schema.FieldsWithDefaultDBValue {
+						if field.Readable {
+							fromColumns = append(fromColumns, clause.Column{Name: field.DBName})
 						}
-					} else {
-						db.AddError(err)
+					}
+					if len(fromColumns) > 0 {
+						db.Statement.AddClause(clause.Returning{Columns: fromColumns})
 					}
 				}
 			}
 		}
-	}
-}
 
-func CreateWithReturning(db *gorm.DB) {
-	if db.Error == nil {
-		if db.Statement.Schema != nil && !db.Statement.Unscoped {
-			for _, c := range db.Statement.Schema.CreateClauses {
-				db.Statement.AddClause(c)
-			}
-		}
-
-		if db.Statement.SQL.String() == "" {
+		if db.Statement.SQL.Len() == 0 {
+			db.Statement.SQL.Grow(180)
 			db.Statement.AddClauseIfNotExists(clause.Insert{})
 			db.Statement.AddClause(ConvertToCreateValues(db.Statement))
 
-			db.Statement.Build("INSERT", "VALUES", "ON CONFLICT")
+			db.Statement.Build(db.Statement.BuildClauses...)
 		}
 
-		if sch := db.Statement.Schema; sch != nil && len(sch.FieldsWithDefaultDBValue) > 0 {
-			db.Statement.WriteString(" RETURNING ")
+		isDryRun := !db.DryRun && db.Error == nil
+		if !isDryRun {
+			return
+		}
 
-			var (
-				fields = make([]*schema.Field, len(sch.FieldsWithDefaultDBValue))
-				values = make([]interface{}, len(sch.FieldsWithDefaultDBValue))
-			)
-
-			for idx, field := range sch.FieldsWithDefaultDBValue {
-				if idx > 0 {
-					db.Statement.WriteByte(',')
+		ok, mode := hasReturning(db, supportReturning)
+		if ok {
+			if c, ok := db.Statement.Clauses["ON CONFLICT"]; ok {
+				if onConflict, _ := c.Expression.(clause.OnConflict); onConflict.DoNothing {
+					mode |= gorm.ScanOnConflictDoNothing
 				}
-
-				fields[idx] = field
-				db.Statement.WriteQuoted(field.DBName)
 			}
 
-			if !db.DryRun && db.Error == nil {
-				db.RowsAffected = 0
-				rows, err := db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+			rows, err := db.Statement.ConnPool.QueryContext(
+				db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...,
+			)
+			if db.AddError(err) == nil {
+				defer func() {
+					db.AddError(rows.Close())
+				}()
+				gorm.Scan(rows, db, mode)
 
-				if err == nil {
-					defer rows.Close()
+				if db.Statement.Result != nil {
+					db.Statement.Result.RowsAffected = db.RowsAffected
+				}
+			}
 
-					switch db.Statement.ReflectValue.Kind() {
-					case reflect.Slice, reflect.Array:
-						c := db.Statement.Clauses["ON CONFLICT"]
-						onConflict, _ := c.Expression.(clause.OnConflict)
+			return
+		}
 
-						for rows.Next() {
-						BEGIN:
-							reflectValue := db.Statement.ReflectValue.Index(int(db.RowsAffected))
-							if reflect.Indirect(reflectValue).Kind() != reflect.Struct {
-								break
-							}
+		result, err := db.Statement.ConnPool.ExecContext(
+			db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...,
+		)
+		if err != nil {
+			db.AddError(err)
+			return
+		}
 
-							for idx, field := range fields {
-								fieldValue := field.ReflectValueOf(reflectValue)
+		db.RowsAffected, _ = result.RowsAffected()
 
-								if onConflict.DoNothing && !fieldValue.IsZero() {
-									db.RowsAffected++
+		if db.Statement.Result != nil {
+			db.Statement.Result.Result = result
+			db.Statement.Result.RowsAffected = db.RowsAffected
+		}
 
-									if int(db.RowsAffected) >= db.Statement.ReflectValue.Len() {
-										return
-									}
+		if db.RowsAffected == 0 {
+			return
+		}
 
-									goto BEGIN
-								}
+		var (
+			pkField     *schema.Field
+			pkFieldName = "@id"
+		)
 
-								values[idx] = fieldValue.Addr().Interface()
-							}
+		if db.Statement.Schema != nil {
+			if db.Statement.Schema.PrioritizedPrimaryField == nil ||
+				!db.Statement.Schema.PrioritizedPrimaryField.HasDefaultValue ||
+				!db.Statement.Schema.PrioritizedPrimaryField.Readable {
+				return
+			}
+			pkField = db.Statement.Schema.PrioritizedPrimaryField
+			pkFieldName = db.Statement.Schema.PrioritizedPrimaryField.DBName
+		}
 
-							db.RowsAffected++
-							if err := rows.Scan(values...); err != nil {
-								db.AddError(err)
-							}
-						}
-					case reflect.Struct:
-						for idx, field := range fields {
-							values[idx] = field.ReflectValueOf(db.Statement.ReflectValue).Addr().Interface()
+		insertID, err := result.LastInsertId()
+		insertOk := err == nil && insertID > 0
+
+		if !insertOk {
+			if !supportReturning {
+				db.AddError(err)
+			}
+			return
+		}
+
+		// append @id column with value for auto-increment primary key
+		// the @id value is correct, when: 1. without setting auto-increment primary key, 2. database AutoIncrementIncrement = 1
+		switch values := db.Statement.Dest.(type) {
+		case map[string]interface{}:
+			values[pkFieldName] = insertID
+		case *map[string]interface{}:
+			(*values)[pkFieldName] = insertID
+		case []map[string]interface{}, *[]map[string]interface{}:
+			mapValues, ok := values.([]map[string]interface{})
+			if !ok {
+				if v, ok := values.(*[]map[string]interface{}); ok {
+					if *v != nil {
+						mapValues = *v
+					}
+				}
+			}
+
+			if config.LastInsertIDReversed {
+				insertID -= int64(len(mapValues)-1) * schema.DefaultAutoIncrementIncrement
+			}
+
+			for _, mapValue := range mapValues {
+				if mapValue != nil {
+					mapValue[pkFieldName] = insertID
+				}
+				insertID += schema.DefaultAutoIncrementIncrement
+			}
+		default:
+			if pkField == nil {
+				return
+			}
+
+			switch db.Statement.ReflectValue.Kind() {
+			case reflect.Slice, reflect.Array:
+				if config.LastInsertIDReversed {
+					for i := db.Statement.ReflectValue.Len() - 1; i >= 0; i-- {
+						rv := db.Statement.ReflectValue.Index(i)
+						if reflect.Indirect(rv).Kind() != reflect.Struct {
+							break
 						}
 
-						if rows.Next() {
-							db.RowsAffected++
-							db.AddError(rows.Scan(values...))
+						_, isZero := pkField.ValueOf(db.Statement.Context, rv)
+						if isZero {
+							db.AddError(pkField.Set(db.Statement.Context, rv, insertID))
+							insertID -= pkField.AutoIncrementIncrement
 						}
 					}
 				} else {
-					db.AddError(err)
+					for i := 0; i < db.Statement.ReflectValue.Len(); i++ {
+						rv := db.Statement.ReflectValue.Index(i)
+						if reflect.Indirect(rv).Kind() != reflect.Struct {
+							break
+						}
+
+						if _, isZero := pkField.ValueOf(db.Statement.Context, rv); isZero {
+							db.AddError(pkField.Set(db.Statement.Context, rv, insertID))
+							insertID += pkField.AutoIncrementIncrement
+						}
+					}
+				}
+			case reflect.Struct:
+				_, isZero := pkField.ValueOf(db.Statement.Context, db.Statement.ReflectValue)
+				if isZero {
+					db.AddError(pkField.Set(db.Statement.Context, db.Statement.ReflectValue, insertID))
 				}
-			}
-		} else if !db.DryRun && db.Error == nil {
-			if result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...); err == nil {
-				db.RowsAffected, _ = result.RowsAffected()
-			} else {
-				db.AddError(err)
 			}
 		}
 	}
 }
 
+// AfterCreate after create hooks
 func AfterCreate(db *gorm.DB) {
 	if db.Error == nil && db.Statement.Schema != nil && !db.Statement.SkipHooks && (db.Statement.Schema.AfterSave || db.Statement.Schema.AfterCreate) {
 		callMethod(db, func(value interface{}, tx *gorm.DB) (called bool) {
-			if db.Statement.Schema.AfterSave {
-				if i, ok := value.(AfterSaveInterface); ok {
-					called = true
-					db.AddError(i.AfterSave(tx))
-				}
-			}
-
 			if db.Statement.Schema.AfterCreate {
 				if i, ok := value.(AfterCreateInterface); ok {
 					called = true
 					db.AddError(i.AfterCreate(tx))
 				}
 			}
+
+			if db.Statement.Schema.AfterSave {
+				if i, ok := value.(AfterSaveInterface); ok {
+					called = true
+					db.AddError(i.AfterSave(tx))
+				}
+			}
 			return called
 		})
 	}
@@ -225,6 +240,8 @@ func AfterCreate(db *gorm.DB) {
 
 // ConvertToCreateValues convert to create values
 func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
+	curTime := stmt.DB.NowFunc()
+
 	switch value := stmt.Dest.(type) {
 	case map[string]interface{}:
 		values = ConvertMapToValuesForCreate(stmt, value)
@@ -237,9 +254,11 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 	default:
 		var (
 			selectColumns, restricted = stmt.SelectAndOmitColumns(true, false)
-			curTime                   = stmt.DB.NowFunc()
+			_, updateTrackTime        = stmt.Get("gorm:update_track_time")
 			isZero                    bool
 		)
+		stmt.Settings.Delete("gorm:update_track_time")
+
 		values = clause.Values{Columns: make([]clause.Column, 0, len(stmt.Schema.DBNames))}
 
 		for _, db := range stmt.Schema.DBNames {
@@ -252,15 +271,18 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 
 		switch stmt.ReflectValue.Kind() {
 		case reflect.Slice, reflect.Array:
-			stmt.SQL.Grow(stmt.ReflectValue.Len() * 18)
-			values.Values = make([][]interface{}, stmt.ReflectValue.Len())
-			defaultValueFieldsHavingValue := map[*schema.Field][]interface{}{}
-			if stmt.ReflectValue.Len() == 0 {
+			rValLen := stmt.ReflectValue.Len()
+			if rValLen == 0 {
 				stmt.AddError(gorm.ErrEmptySlice)
 				return
 			}
 
-			for i := 0; i < stmt.ReflectValue.Len(); i++ {
+			stmt.SQL.Grow(rValLen * 18)
+			stmt.Vars = make([]interface{}, 0, rValLen*len(values.Columns))
+			values.Values = make([][]interface{}, rValLen)
+
+			defaultValueFieldsHavingValue := map[*schema.Field][]interface{}{}
+			for i := 0; i < rValLen; i++ {
 				rv := reflect.Indirect(stmt.ReflectValue.Index(i))
 				if !rv.IsValid() {
 					stmt.AddError(fmt.Errorf("slice data #%v is invalid: %w", i, gorm.ErrInvalidData))
@@ -270,41 +292,41 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 				values.Values[i] = make([]interface{}, len(values.Columns))
 				for idx, column := range values.Columns {
 					field := stmt.Schema.FieldsByDBName[column.Name]
-					if values.Values[i][idx], isZero = field.ValueOf(rv); isZero {
+					if values.Values[i][idx], isZero = field.ValueOf(stmt.Context, rv); isZero {
 						if field.DefaultValueInterface != nil {
 							values.Values[i][idx] = field.DefaultValueInterface
-							field.Set(rv, field.DefaultValueInterface)
+							stmt.AddError(field.Set(stmt.Context, rv, field.DefaultValueInterface))
 						} else if field.AutoCreateTime > 0 || field.AutoUpdateTime > 0 {
-							field.Set(rv, curTime)
-							values.Values[i][idx], _ = field.ValueOf(rv)
-						}
-					} else if field.AutoUpdateTime > 0 {
-						if _, ok := stmt.DB.InstanceGet("gorm:update_track_time"); ok {
-							field.Set(rv, curTime)
-							values.Values[i][idx], _ = field.ValueOf(rv)
+							stmt.AddError(field.Set(stmt.Context, rv, curTime))
+							values.Values[i][idx], _ = field.ValueOf(stmt.Context, rv)
 						}
+					} else if field.AutoUpdateTime > 0 && updateTrackTime {
+						stmt.AddError(field.Set(stmt.Context, rv, curTime))
+						values.Values[i][idx], _ = field.ValueOf(stmt.Context, rv)
 					}
 				}
 
 				for _, field := range stmt.Schema.FieldsWithDefaultDBValue {
 					if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {
-						if v, isZero := field.ValueOf(rv); !isZero {
+						if rvOfvalue, isZero := field.ValueOf(stmt.Context, rv); !isZero {
 							if len(defaultValueFieldsHavingValue[field]) == 0 {
-								defaultValueFieldsHavingValue[field] = make([]interface{}, stmt.ReflectValue.Len())
+								defaultValueFieldsHavingValue[field] = make([]interface{}, rValLen)
 							}
-							defaultValueFieldsHavingValue[field][i] = v
+							defaultValueFieldsHavingValue[field][i] = rvOfvalue
 						}
 					}
 				}
 			}
 
-			for field, vs := range defaultValueFieldsHavingValue {
-				values.Columns = append(values.Columns, clause.Column{Name: field.DBName})
-				for idx := range values.Values {
-					if vs[idx] == nil {
-						values.Values[idx] = append(values.Values[idx], stmt.Dialector.DefaultValueOf(field))
-					} else {
-						values.Values[idx] = append(values.Values[idx], vs[idx])
+			for _, field := range stmt.Schema.FieldsWithDefaultDBValue {
+				if vs, ok := defaultValueFieldsHavingValue[field]; ok {
+					values.Columns = append(values.Columns, clause.Column{Name: field.DBName})
+					for idx := range values.Values {
+						if vs[idx] == nil {
+							values.Values[idx] = append(values.Values[idx], stmt.DefaultValueOf(field))
+						} else {
+							values.Values[idx] = append(values.Values[idx], vs[idx])
+						}
 					}
 				}
 			}
@@ -312,27 +334,25 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 			values.Values = [][]interface{}{make([]interface{}, len(values.Columns))}
 			for idx, column := range values.Columns {
 				field := stmt.Schema.FieldsByDBName[column.Name]
-				if values.Values[0][idx], isZero = field.ValueOf(stmt.ReflectValue); isZero {
+				if values.Values[0][idx], isZero = field.ValueOf(stmt.Context, stmt.ReflectValue); isZero {
 					if field.DefaultValueInterface != nil {
 						values.Values[0][idx] = field.DefaultValueInterface
-						field.Set(stmt.ReflectValue, field.DefaultValueInterface)
+						stmt.AddError(field.Set(stmt.Context, stmt.ReflectValue, field.DefaultValueInterface))
 					} else if field.AutoCreateTime > 0 || field.AutoUpdateTime > 0 {
-						field.Set(stmt.ReflectValue, curTime)
-						values.Values[0][idx], _ = field.ValueOf(stmt.ReflectValue)
-					}
-				} else if field.AutoUpdateTime > 0 {
-					if _, ok := stmt.DB.InstanceGet("gorm:update_track_time"); ok {
-						field.Set(stmt.ReflectValue, curTime)
-						values.Values[0][idx], _ = field.ValueOf(stmt.ReflectValue)
+						stmt.AddError(field.Set(stmt.Context, stmt.ReflectValue, curTime))
+						values.Values[0][idx], _ = field.ValueOf(stmt.Context, stmt.ReflectValue)
 					}
+				} else if field.AutoUpdateTime > 0 && updateTrackTime {
+					stmt.AddError(field.Set(stmt.Context, stmt.ReflectValue, curTime))
+					values.Values[0][idx], _ = field.ValueOf(stmt.Context, stmt.ReflectValue)
 				}
 			}
 
 			for _, field := range stmt.Schema.FieldsWithDefaultDBValue {
-				if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {
-					if v, isZero := field.ValueOf(stmt.ReflectValue); !isZero {
+				if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) && field.DefaultValueInterface == nil {
+					if rvOfvalue, isZero := field.ValueOf(stmt.Context, stmt.ReflectValue); !isZero {
 						values.Columns = append(values.Columns, clause.Column{Name: field.DBName})
-						values.Values[0] = append(values.Values[0], v)
+						values.Values[0] = append(values.Values[0], rvOfvalue)
 					}
 				}
 			}
@@ -343,17 +363,39 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 
 	if c, ok := stmt.Clauses["ON CONFLICT"]; ok {
 		if onConflict, _ := c.Expression.(clause.OnConflict); onConflict.UpdateAll {
-			if stmt.Schema != nil && len(values.Columns) > 1 {
+			if stmt.Schema != nil && len(values.Columns) >= 1 {
+				selectColumns, restricted := stmt.SelectAndOmitColumns(true, true)
+
 				columns := make([]string, 0, len(values.Columns)-1)
 				for _, column := range values.Columns {
 					if field := stmt.Schema.LookUpField(column.Name); field != nil {
-						if !field.PrimaryKey && (!field.HasDefaultValue || field.DefaultValueInterface != nil) && field.AutoCreateTime == 0 {
-							columns = append(columns, column.Name)
+						if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {
+							if !field.PrimaryKey && (!field.HasDefaultValue || field.DefaultValueInterface != nil ||
+								strings.EqualFold(field.DefaultValue, "NULL")) && field.AutoCreateTime == 0 {
+								if field.AutoUpdateTime > 0 {
+									assignment := clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: curTime}
+									switch field.AutoUpdateTime {
+									case schema.UnixNanosecond:
+										assignment.Value = curTime.UnixNano()
+									case schema.UnixMillisecond:
+										assignment.Value = curTime.UnixMilli()
+									case schema.UnixSecond:
+										assignment.Value = curTime.Unix()
+									}
+
+									onConflict.DoUpdates = append(onConflict.DoUpdates, assignment)
+								} else {
+									columns = append(columns, column.Name)
+								}
+							}
 						}
 					}
 				}
 
-				onConflict.DoUpdates = clause.AssignmentColumns(columns)
+				onConflict.DoUpdates = append(onConflict.DoUpdates, clause.AssignmentColumns(columns)...)
+				if len(onConflict.DoUpdates) == 0 {
+					onConflict.DoNothing = true
+				}
 
 				// use primary fields as default OnConflict columns
 				if len(onConflict.Columns) == 0 {

callbacks/create_test.go

@@ -0,0 +1,71 @@
+package callbacks
+
+import (
+	"reflect"
+	"sync"
+	"testing"
+	"time"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+	"gorm.io/gorm/schema"
+)
+
+var schemaCache = &sync.Map{}
+
+func TestConvertToCreateValues_DestType_Slice(t *testing.T) {
+	type user struct {
+		ID    int `gorm:"primaryKey"`
+		Name  string
+		Email string `gorm:"default:(-)"`
+		Age   int    `gorm:"default:(-)"`
+	}
+
+	s, err := schema.Parse(&user{}, schemaCache, schema.NamingStrategy{})
+	if err != nil {
+		t.Errorf("parse schema error: %v, is not expected", err)
+		return
+	}
+	dest := []*user{
+		{
+			ID:    1,
+			Name:  "alice",
+			Email: "email",
+			Age:   18,
+		},
+		{
+			ID:    2,
+			Name:  "bob",
+			Email: "email",
+			Age:   19,
+		},
+	}
+	stmt := &gorm.Statement{
+		DB: &gorm.DB{
+			Config: &gorm.Config{
+				NowFunc: func() time.Time { return time.Time{} },
+			},
+			Statement: &gorm.Statement{
+				Settings: sync.Map{},
+				Schema:   s,
+			},
+		},
+		ReflectValue: reflect.ValueOf(dest),
+		Dest:         dest,
+	}
+
+	stmt.Schema = s
+
+	values := ConvertToCreateValues(stmt)
+	expected := clause.Values{
+		// column has value + defaultValue column has value (which should have a stable order)
+		Columns: []clause.Column{{Name: "name"}, {Name: "email"}, {Name: "age"}, {Name: "id"}},
+		Values: [][]interface{}{
+			{"alice", "email", 18, 1},
+			{"bob", "email", 19, 2},
+		},
+	}
+	if !reflect.DeepEqual(expected, values) {
+		t.Errorf("expected: %v got %v", expected, values)
+	}
+}

callbacks/delete.go

@@ -7,6 +7,7 @@ import (
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils"
 )
 
 func BeforeDelete(db *gorm.DB) {
@@ -25,99 +26,110 @@ func BeforeDelete(db *gorm.DB) {
 func DeleteBeforeAssociations(db *gorm.DB) {
 	if db.Error == nil && db.Statement.Schema != nil {
 		selectColumns, restricted := db.Statement.SelectAndOmitColumns(true, false)
+		if !restricted {
+			return
+		}
 
-		if restricted {
-			for column, v := range selectColumns {
-				if v {
-					if rel, ok := db.Statement.Schema.Relationships.Relations[column]; ok {
-						switch rel.Type {
-						case schema.HasOne, schema.HasMany:
-							queryConds := rel.ToQueryConditions(db.Statement.ReflectValue)
-							modelValue := reflect.New(rel.FieldSchema.ModelType).Interface()
-							tx := db.Session(&gorm.Session{NewDB: true}).Model(modelValue)
-							withoutConditions := false
-							if db.Statement.Unscoped {
-								tx = tx.Unscoped()
-							}
+		for column, v := range selectColumns {
+			if !v {
+				continue
+			}
 
-							if len(db.Statement.Selects) > 0 {
-								selects := make([]string, 0, len(db.Statement.Selects))
-								for _, s := range db.Statement.Selects {
-									if s == clause.Associations {
-										selects = append(selects, s)
-									} else if strings.HasPrefix(s, column+".") {
-										selects = append(selects, strings.TrimPrefix(s, column+"."))
-									}
-								}
+			rel, ok := db.Statement.Schema.Relationships.Relations[column]
+			if !ok {
+				continue
+			}
 
-								if len(selects) > 0 {
-									tx = tx.Select(selects)
-								}
-							}
+			switch rel.Type {
+			case schema.HasOne, schema.HasMany:
+				queryConds := rel.ToQueryConditions(db.Statement.Context, db.Statement.ReflectValue)
+				modelValue := reflect.New(rel.FieldSchema.ModelType).Interface()
+				tx := db.Session(&gorm.Session{NewDB: true}).Model(modelValue)
+				withoutConditions := false
+				if db.Statement.Unscoped {
+					tx = tx.Unscoped()
+				}
 
-							for _, cond := range queryConds {
-								if c, ok := cond.(clause.IN); ok && len(c.Values) == 0 {
-									withoutConditions = true
-									break
-								}
-							}
-
-							if !withoutConditions {
-								if db.AddError(tx.Clauses(clause.Where{Exprs: queryConds}).Delete(modelValue).Error) != nil {
-									return
-								}
-							}
-						case schema.Many2Many:
-							var (
-								queryConds     = make([]clause.Expression, 0, len(rel.References))
-								foreignFields  = make([]*schema.Field, 0, len(rel.References))
-								relForeignKeys = make([]string, 0, len(rel.References))
-								modelValue     = reflect.New(rel.JoinTable.ModelType).Interface()
-								table          = rel.JoinTable.Table
-								tx             = db.Session(&gorm.Session{NewDB: true}).Model(modelValue).Table(table)
-							)
-
-							for _, ref := range rel.References {
-								if ref.OwnPrimaryKey {
-									foreignFields = append(foreignFields, ref.PrimaryKey)
-									relForeignKeys = append(relForeignKeys, ref.ForeignKey.DBName)
-								} else if ref.PrimaryValue != "" {
-									queryConds = append(queryConds, clause.Eq{
-										Column: clause.Column{Table: rel.JoinTable.Table, Name: ref.ForeignKey.DBName},
-										Value:  ref.PrimaryValue,
-									})
-								}
-							}
-
-							_, foreignValues := schema.GetIdentityFieldValuesMap(db.Statement.ReflectValue, foreignFields)
-							column, values := schema.ToQueryValues(table, relForeignKeys, foreignValues)
-							queryConds = append(queryConds, clause.IN{Column: column, Values: values})
-
-							if db.AddError(tx.Clauses(clause.Where{Exprs: queryConds}).Delete(modelValue).Error) != nil {
-								return
-							}
+				if len(db.Statement.Selects) > 0 {
+					selects := make([]string, 0, len(db.Statement.Selects))
+					for _, s := range db.Statement.Selects {
+						if s == clause.Associations {
+							selects = append(selects, s)
+						} else if columnPrefix := column + "."; strings.HasPrefix(s, columnPrefix) {
+							selects = append(selects, strings.TrimPrefix(s, columnPrefix))
 						}
 					}
+
+					if len(selects) > 0 {
+						tx = tx.Select(selects)
+					}
+				}
+
+				for _, cond := range queryConds {
+					if c, ok := cond.(clause.IN); ok && len(c.Values) == 0 {
+						withoutConditions = true
+						break
+					}
+				}
+
+				if !withoutConditions && db.AddError(tx.Clauses(clause.Where{Exprs: queryConds}).Delete(modelValue).Error) != nil {
+					return
+				}
+			case schema.Many2Many:
+				var (
+					queryConds     = make([]clause.Expression, 0, len(rel.References))
+					foreignFields  = make([]*schema.Field, 0, len(rel.References))
+					relForeignKeys = make([]string, 0, len(rel.References))
+					modelValue     = reflect.New(rel.JoinTable.ModelType).Interface()
+					table          = rel.JoinTable.Table
+					tx             = db.Session(&gorm.Session{NewDB: true}).Model(modelValue).Table(table)
+				)
+
+				for _, ref := range rel.References {
+					if ref.OwnPrimaryKey {
+						foreignFields = append(foreignFields, ref.PrimaryKey)
+						relForeignKeys = append(relForeignKeys, ref.ForeignKey.DBName)
+					} else if ref.PrimaryValue != "" {
+						queryConds = append(queryConds, clause.Eq{
+							Column: clause.Column{Table: rel.JoinTable.Table, Name: ref.ForeignKey.DBName},
+							Value:  ref.PrimaryValue,
+						})
+					}
+				}
+
+				_, foreignValues := schema.GetIdentityFieldValuesMap(db.Statement.Context, db.Statement.ReflectValue, foreignFields)
+				column, values := schema.ToQueryValues(table, relForeignKeys, foreignValues)
+				queryConds = append(queryConds, clause.IN{Column: column, Values: values})
+
+				if db.AddError(tx.Clauses(clause.Where{Exprs: queryConds}).Delete(modelValue).Error) != nil {
+					return
 				}
 			}
 		}
+
 	}
 }
 
-func Delete(db *gorm.DB) {
-	if db.Error == nil {
-		if db.Statement.Schema != nil && !db.Statement.Unscoped {
+func Delete(config *Config) func(db *gorm.DB) {
+	supportReturning := utils.Contains(config.DeleteClauses, "RETURNING")
+
+	return func(db *gorm.DB) {
+		if db.Error != nil {
+			return
+		}
+
+		if db.Statement.Schema != nil {
 			for _, c := range db.Statement.Schema.DeleteClauses {
 				db.Statement.AddClause(c)
 			}
 		}
 
-		if db.Statement.SQL.String() == "" {
+		if db.Statement.SQL.Len() == 0 {
 			db.Statement.SQL.Grow(100)
 			db.Statement.AddClauseIfNotExists(clause.Delete{})
 
 			if db.Statement.Schema != nil {
-				_, queryValues := schema.GetIdentityFieldValuesMap(db.Statement.ReflectValue, db.Statement.Schema.PrimaryFields)
+				_, queryValues := schema.GetIdentityFieldValuesMap(db.Statement.Context, db.Statement.ReflectValue, db.Statement.Schema.PrimaryFields)
 				column, values := schema.ToQueryValues(db.Statement.Table, db.Statement.Schema.PrimaryFieldDBNames, queryValues)
 
 				if len(values) > 0 {
@@ -125,7 +137,7 @@ func Delete(db *gorm.DB) {
 				}
 
 				if db.Statement.ReflectValue.CanAddr() && db.Statement.Dest != db.Statement.Model && db.Statement.Model != nil {
-					_, queryValues = schema.GetIdentityFieldValuesMap(reflect.ValueOf(db.Statement.Model), db.Statement.Schema.PrimaryFields)
+					_, queryValues = schema.GetIdentityFieldValuesMap(db.Statement.Context, reflect.ValueOf(db.Statement.Model), db.Statement.Schema.PrimaryFields)
 					column, values = schema.ToQueryValues(db.Statement.Table, db.Statement.Schema.PrimaryFieldDBNames, queryValues)
 
 					if len(values) > 0 {
@@ -135,21 +147,36 @@ func Delete(db *gorm.DB) {
 			}
 
 			db.Statement.AddClauseIfNotExists(clause.From{})
-			db.Statement.Build("DELETE", "FROM", "WHERE")
+
+			db.Statement.Build(db.Statement.BuildClauses...)
 		}
 
-		if _, ok := db.Statement.Clauses["WHERE"]; !db.AllowGlobalUpdate && !ok && db.Error == nil {
-			db.AddError(gorm.ErrMissingWhereClause)
-			return
-		}
+		checkMissingWhereConditions(db)
 
 		if !db.DryRun && db.Error == nil {
-			result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+			ok, mode := hasReturning(db, supportReturning)
+			if !ok {
+				result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
 
-			if err == nil {
-				db.RowsAffected, _ = result.RowsAffected()
-			} else {
-				db.AddError(err)
+				if db.AddError(err) == nil {
+					db.RowsAffected, _ = result.RowsAffected()
+
+					if db.Statement.Result != nil {
+						db.Statement.Result.Result = result
+						db.Statement.Result.RowsAffected = db.RowsAffected
+					}
+				}
+
+				return
+			}
+
+			if rows, err := db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...); db.AddError(err) == nil {
+				gorm.Scan(rows, db, mode)
+
+				if db.Statement.Result != nil {
+					db.Statement.Result.RowsAffected = db.RowsAffected
+				}
+				db.AddError(rows.Close())
 			}
 		}
 	}

callbacks/helper.go

@@ -1,6 +1,7 @@
 package callbacks
 
 import (
+	"reflect"
 	"sort"
 
 	"gorm.io/gorm"
@@ -12,7 +13,7 @@ func ConvertMapToValuesForCreate(stmt *gorm.Statement, mapValue map[string]inter
 	values.Columns = make([]clause.Column, 0, len(mapValue))
 	selectColumns, restricted := stmt.SelectAndOmitColumns(true, false)
 
-	var keys = make([]string, 0, len(mapValue))
+	keys := make([]string, 0, len(mapValue))
 	for k := range mapValue {
 		keys = append(keys, k)
 	}
@@ -40,17 +41,20 @@ func ConvertMapToValuesForCreate(stmt *gorm.Statement, mapValue map[string]inter
 
 // ConvertSliceOfMapToValuesForCreate convert slice of map to values
 func ConvertSliceOfMapToValuesForCreate(stmt *gorm.Statement, mapValues []map[string]interface{}) (values clause.Values) {
-	var (
-		columns                   = make([]string, 0, len(mapValues))
-		result                    = map[string][]interface{}{}
-		selectColumns, restricted = stmt.SelectAndOmitColumns(true, false)
-	)
+	columns := make([]string, 0, len(mapValues))
 
+	// when the length of mapValues is zero,return directly here
+	// no need to call stmt.SelectAndOmitColumns method
 	if len(mapValues) == 0 {
 		stmt.AddError(gorm.ErrEmptySlice)
 		return
 	}
 
+	var (
+		result                    = make(map[string][]interface{}, len(mapValues))
+		selectColumns, restricted = stmt.SelectAndOmitColumns(true, false)
+	)
+
 	for idx, mapValue := range mapValues {
 		for k, v := range mapValue {
 			if stmt.Schema != nil {
@@ -88,3 +92,61 @@ func ConvertSliceOfMapToValuesForCreate(stmt *gorm.Statement, mapValues []map[st
 	}
 	return
 }
+
+func hasReturning(tx *gorm.DB, supportReturning bool) (bool, gorm.ScanMode) {
+	if supportReturning {
+		if c, ok := tx.Statement.Clauses["RETURNING"]; ok {
+			returning, _ := c.Expression.(clause.Returning)
+			if len(returning.Columns) == 0 || (len(returning.Columns) == 1 && returning.Columns[0].Name == "*") {
+				return true, 0
+			}
+			return true, gorm.ScanUpdate
+		}
+	}
+	return false, 0
+}
+
+func checkMissingWhereConditions(db *gorm.DB) {
+	if !db.AllowGlobalUpdate && db.Error == nil {
+		where, withCondition := db.Statement.Clauses["WHERE"]
+		if withCondition {
+			if _, withSoftDelete := db.Statement.Clauses["soft_delete_enabled"]; withSoftDelete {
+				whereClause, _ := where.Expression.(clause.Where)
+				withCondition = len(whereClause.Exprs) > 1
+			}
+		}
+		if !withCondition {
+			db.AddError(gorm.ErrMissingWhereClause)
+		}
+		return
+	}
+}
+
+type visitMap = map[reflect.Value]bool
+
+// Check if circular values, return true if loaded
+func loadOrStoreVisitMap(visitMap *visitMap, v reflect.Value) (loaded bool) {
+	if v.Kind() == reflect.Ptr {
+		v = v.Elem()
+	}
+
+	switch v.Kind() {
+	case reflect.Slice, reflect.Array:
+		loaded = true
+		for i := 0; i < v.Len(); i++ {
+			if !loadOrStoreVisitMap(visitMap, v.Index(i)) {
+				loaded = false
+			}
+		}
+	case reflect.Struct, reflect.Interface:
+		if v.CanAddr() {
+			p := v.Addr()
+			if _, ok := (*visitMap)[p]; ok {
+				return true
+			}
+			(*visitMap)[p] = true
+		}
+	}
+
+	return
+}

callbacks/helper_test.go

@@ -0,0 +1,157 @@
+package callbacks
+
+import (
+	"reflect"
+	"testing"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+func TestLoadOrStoreVisitMap(t *testing.T) {
+	var vm visitMap
+	var loaded bool
+	type testM struct {
+		Name string
+	}
+
+	t1 := testM{Name: "t1"}
+	t2 := testM{Name: "t2"}
+	t3 := testM{Name: "t3"}
+
+	vm = make(visitMap)
+	if loaded = loadOrStoreVisitMap(&vm, reflect.ValueOf(&t1)); loaded {
+		t.Fatalf("loaded should be false")
+	}
+
+	if loaded = loadOrStoreVisitMap(&vm, reflect.ValueOf(&t1)); !loaded {
+		t.Fatalf("loaded should be true")
+	}
+
+	// t1 already exist but t2 not
+	if loaded = loadOrStoreVisitMap(&vm, reflect.ValueOf([]*testM{&t1, &t2, &t3})); loaded {
+		t.Fatalf("loaded should be false")
+	}
+
+	if loaded = loadOrStoreVisitMap(&vm, reflect.ValueOf([]*testM{&t2, &t3})); !loaded {
+		t.Fatalf("loaded should be true")
+	}
+}
+
+func TestConvertMapToValuesForCreate(t *testing.T) {
+	testCase := []struct {
+		name   string
+		input  map[string]interface{}
+		expect clause.Values
+	}{
+		{
+			name: "Test convert string value",
+			input: map[string]interface{}{
+				"name": "my name",
+			},
+			expect: clause.Values{
+				Columns: []clause.Column{{Name: "name"}},
+				Values:  [][]interface{}{{"my name"}},
+			},
+		},
+		{
+			name: "Test convert int value",
+			input: map[string]interface{}{
+				"age": 18,
+			},
+			expect: clause.Values{
+				Columns: []clause.Column{{Name: "age"}},
+				Values:  [][]interface{}{{18}},
+			},
+		},
+		{
+			name: "Test convert float value",
+			input: map[string]interface{}{
+				"score": 99.5,
+			},
+			expect: clause.Values{
+				Columns: []clause.Column{{Name: "score"}},
+				Values:  [][]interface{}{{99.5}},
+			},
+		},
+		{
+			name: "Test convert bool value",
+			input: map[string]interface{}{
+				"active": true,
+			},
+			expect: clause.Values{
+				Columns: []clause.Column{{Name: "active"}},
+				Values:  [][]interface{}{{true}},
+			},
+		},
+	}
+
+	for _, tc := range testCase {
+		t.Run(tc.name, func(t *testing.T) {
+			actual := ConvertMapToValuesForCreate(&gorm.Statement{}, tc.input)
+			if !reflect.DeepEqual(actual, tc.expect) {
+				t.Errorf("expect %v got %v", tc.expect, actual)
+			}
+		})
+	}
+}
+
+func TestConvertSliceOfMapToValuesForCreate(t *testing.T) {
+	testCase := []struct {
+		name   string
+		input  []map[string]interface{}
+		expect clause.Values
+	}{
+		{
+			name: "Test convert slice of string value",
+			input: []map[string]interface{}{
+				{"name": "my name"},
+			},
+			expect: clause.Values{
+				Columns: []clause.Column{{Name: "name"}},
+				Values:  [][]interface{}{{"my name"}},
+			},
+		},
+		{
+			name: "Test convert slice of int value",
+			input: []map[string]interface{}{
+				{"age": 18},
+			},
+			expect: clause.Values{
+				Columns: []clause.Column{{Name: "age"}},
+				Values:  [][]interface{}{{18}},
+			},
+		},
+		{
+			name: "Test convert slice of float value",
+			input: []map[string]interface{}{
+				{"score": 99.5},
+			},
+			expect: clause.Values{
+				Columns: []clause.Column{{Name: "score"}},
+				Values:  [][]interface{}{{99.5}},
+			},
+		},
+		{
+			name: "Test convert slice of bool value",
+			input: []map[string]interface{}{
+				{"active": true},
+			},
+			expect: clause.Values{
+				Columns: []clause.Column{{Name: "active"}},
+				Values:  [][]interface{}{{true}},
+			},
+		},
+	}
+
+	for _, tc := range testCase {
+		t.Run(tc.name, func(t *testing.T) {
+			actual := ConvertSliceOfMapToValuesForCreate(&gorm.Statement{}, tc.input)
+
+			if !reflect.DeepEqual(actual, tc.expect) {
+				t.Errorf("expected %v but got %v", tc.expect, actual)
+			}
+		})
+	}
+
+}

callbacks/preload.go

@@ -1,7 +1,10 @@
 package callbacks
 
 import (
+	"fmt"
 	"reflect"
+	"sort"
+	"strings"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
@@ -9,10 +12,179 @@ import (
 	"gorm.io/gorm/utils"
 )
 
-func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preloads map[string][]interface{}) {
+// parsePreloadMap extracts nested preloads. e.g.
+//
+//	// schema has a "k0" relation and a "k7.k8" embedded relation
+//	parsePreloadMap(schema, map[string][]interface{}{
+//		clause.Associations: {"arg1"},
+//		"k1":                {"arg2"},
+//		"k2.k3":             {"arg3"},
+//		"k4.k5.k6":          {"arg4"},
+//	})
+//	// preloadMap is
+//	map[string]map[string][]interface{}{
+//		"k0": {},
+//		"k7": {
+//			"k8": {},
+//		},
+//		"k1": {},
+//		"k2": {
+//			"k3": {"arg3"},
+//		},
+//		"k4": {
+//			"k5.k6": {"arg4"},
+//		},
+//	}
+func parsePreloadMap(s *schema.Schema, preloads map[string][]interface{}) map[string]map[string][]interface{} {
+	preloadMap := map[string]map[string][]interface{}{}
+	setPreloadMap := func(name, value string, args []interface{}) {
+		if _, ok := preloadMap[name]; !ok {
+			preloadMap[name] = map[string][]interface{}{}
+		}
+		if value != "" {
+			preloadMap[name][value] = args
+		}
+	}
+
+	for name, args := range preloads {
+		preloadFields := strings.Split(name, ".")
+		value := strings.TrimPrefix(strings.TrimPrefix(name, preloadFields[0]), ".")
+		if preloadFields[0] == clause.Associations {
+			for _, relation := range s.Relationships.Relations {
+				if relation.Schema == s {
+					setPreloadMap(relation.Name, value, args)
+				}
+			}
+
+			for embedded, embeddedRelations := range s.Relationships.EmbeddedRelations {
+				for _, value := range embeddedValues(embeddedRelations) {
+					setPreloadMap(embedded, value, args)
+				}
+			}
+		} else {
+			setPreloadMap(preloadFields[0], value, args)
+		}
+	}
+	return preloadMap
+}
+
+func embeddedValues(embeddedRelations *schema.Relationships) []string {
+	if embeddedRelations == nil {
+		return nil
+	}
+	names := make([]string, 0, len(embeddedRelations.Relations)+len(embeddedRelations.EmbeddedRelations))
+	for _, relation := range embeddedRelations.Relations {
+		// skip first struct name
+		names = append(names, strings.Join(relation.Field.EmbeddedBindNames[1:], "."))
+	}
+	for _, relations := range embeddedRelations.EmbeddedRelations {
+		names = append(names, embeddedValues(relations)...)
+	}
+	return names
+}
+
+// preloadEntryPoint enters layer by layer. It will call real preload if it finds the right entry point.
+// If the current relationship is embedded or joined, current query will be ignored.
+//
+//nolint:cyclop
+func preloadEntryPoint(db *gorm.DB, joins []string, relationships *schema.Relationships, preloads map[string][]interface{}, associationsConds []interface{}) error {
+	preloadMap := parsePreloadMap(db.Statement.Schema, preloads)
+
+	// avoid random traversal of the map
+	preloadNames := make([]string, 0, len(preloadMap))
+	for key := range preloadMap {
+		preloadNames = append(preloadNames, key)
+	}
+	sort.Strings(preloadNames)
+
+	isJoined := func(name string) (joined bool, nestedJoins []string) {
+		for _, join := range joins {
+			if _, ok := relationships.Relations[join]; ok && name == join {
+				joined = true
+				continue
+			}
+			join0, join1, cut := strings.Cut(join, ".")
+			if cut {
+				if _, ok := relationships.Relations[join0]; ok && name == join0 {
+					joined = true
+					nestedJoins = append(nestedJoins, join1)
+				}
+			}
+		}
+		return joined, nestedJoins
+	}
+
+	for _, name := range preloadNames {
+		if relations := relationships.EmbeddedRelations[name]; relations != nil {
+			if err := preloadEntryPoint(db, joins, relations, preloadMap[name], associationsConds); err != nil {
+				return err
+			}
+		} else if rel := relationships.Relations[name]; rel != nil {
+			if joined, nestedJoins := isJoined(name); joined {
+				switch rv := db.Statement.ReflectValue; rv.Kind() {
+				case reflect.Slice, reflect.Array:
+					if rv.Len() > 0 {
+						reflectValue := rel.FieldSchema.MakeSlice().Elem()
+						for i := 0; i < rv.Len(); i++ {
+							frv := rel.Field.ReflectValueOf(db.Statement.Context, rv.Index(i))
+							if frv.Kind() != reflect.Ptr {
+								reflectValue = reflect.Append(reflectValue, frv.Addr())
+							} else {
+								if frv.IsNil() {
+									continue
+								}
+								reflectValue = reflect.Append(reflectValue, frv)
+							}
+						}
+
+						tx := preloadDB(db, reflectValue, reflectValue.Interface())
+						if err := preloadEntryPoint(tx, nestedJoins, &tx.Statement.Schema.Relationships, preloadMap[name], associationsConds); err != nil {
+							return err
+						}
+					}
+				case reflect.Struct, reflect.Pointer:
+					reflectValue := rel.Field.ReflectValueOf(db.Statement.Context, rv)
+					tx := preloadDB(db, reflectValue, reflectValue.Interface())
+					if err := preloadEntryPoint(tx, nestedJoins, &tx.Statement.Schema.Relationships, preloadMap[name], associationsConds); err != nil {
+						return err
+					}
+				default:
+					return gorm.ErrInvalidData
+				}
+			} else {
+				tx := db.Table("").Session(&gorm.Session{Context: db.Statement.Context, SkipHooks: db.Statement.SkipHooks})
+				tx.Statement.ReflectValue = db.Statement.ReflectValue
+				tx.Statement.Unscoped = db.Statement.Unscoped
+				if err := preload(tx, rel, append(preloads[name], associationsConds...), preloadMap[name]); err != nil {
+					return err
+				}
+			}
+		} else {
+			return fmt.Errorf("%s: %w for schema %s", name, gorm.ErrUnsupportedRelation, db.Statement.Schema.Name)
+		}
+	}
+	return nil
+}
+
+func preloadDB(db *gorm.DB, reflectValue reflect.Value, dest interface{}) *gorm.DB {
+	tx := db.Session(&gorm.Session{Context: db.Statement.Context, NewDB: true, SkipHooks: db.Statement.SkipHooks, Initialized: true})
+	db.Statement.Settings.Range(func(k, v interface{}) bool {
+		tx.Statement.Settings.Store(k, v)
+		return true
+	})
+
+	if err := tx.Statement.Parse(dest); err != nil {
+		tx.AddError(err)
+		return tx
+	}
+	tx.Statement.ReflectValue = reflectValue
+	tx.Statement.Unscoped = db.Statement.Unscoped
+	return tx
+}
+
+func preload(tx *gorm.DB, rel *schema.Relationship, conds []interface{}, preloads map[string][]interface{}) error {
 	var (
-		reflectValue     = db.Statement.ReflectValue
-		tx               = db.Session(&gorm.Session{NewDB: true}).Model(nil).Session(&gorm.Session{SkipHooks: db.Statement.SkipHooks})
+		reflectValue     = tx.Statement.ReflectValue
 		relForeignKeys   []string
 		relForeignFields []*schema.Field
 		foreignFields    []*schema.Field
@@ -21,13 +193,7 @@ func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 		inlineConds      []interface{}
 	)
 
-	db.Statement.Settings.Range(func(k, v interface{}) bool {
-		tx.Statement.Settings.Store(k, v)
-		return true
-	})
-
 	if rel.JoinTable != nil {
-
 		var (
 			joinForeignFields    = make([]*schema.Field, 0, len(rel.References))
 			joinRelForeignFields = make([]*schema.Field, 0, len(rel.References))
@@ -48,25 +214,28 @@ func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 			}
 		}
 
-		joinIdentityMap, joinForeignValues := schema.GetIdentityFieldValuesMap(reflectValue, foreignFields)
+		joinIdentityMap, joinForeignValues := schema.GetIdentityFieldValuesMap(tx.Statement.Context, reflectValue, foreignFields)
 		if len(joinForeignValues) == 0 {
-			return
+			return nil
 		}
 
 		joinResults := rel.JoinTable.MakeSlice().Elem()
 		column, values := schema.ToQueryValues(clause.CurrentTable, joinForeignKeys, joinForeignValues)
-		db.AddError(tx.Where(clause.IN{Column: column, Values: values}).Find(joinResults.Addr().Interface()).Error)
+		if err := tx.Where(clause.IN{Column: column, Values: values}).Find(joinResults.Addr().Interface()).Error; err != nil {
+			return err
+		}
 
 		// convert join identity map to relation identity map
 		fieldValues := make([]interface{}, len(joinForeignFields))
 		joinFieldValues := make([]interface{}, len(joinRelForeignFields))
 		for i := 0; i < joinResults.Len(); i++ {
+			joinIndexValue := joinResults.Index(i)
 			for idx, field := range joinForeignFields {
-				fieldValues[idx], _ = field.ValueOf(joinResults.Index(i))
+				fieldValues[idx], _ = field.ValueOf(tx.Statement.Context, joinIndexValue)
 			}
 
 			for idx, field := range joinRelForeignFields {
-				joinFieldValues[idx], _ = field.ValueOf(joinResults.Index(i))
+				joinFieldValues[idx], _ = field.ValueOf(tx.Statement.Context, joinIndexValue)
 			}
 
 			if results, ok := joinIdentityMap[utils.ToStringKey(fieldValues...)]; ok {
@@ -75,7 +244,7 @@ func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 			}
 		}
 
-		_, foreignValues = schema.GetIdentityFieldValuesMap(joinResults, joinRelForeignFields)
+		_, foreignValues = schema.GetIdentityFieldValuesMap(tx.Statement.Context, joinResults, joinRelForeignFields)
 	} else {
 		for _, ref := range rel.References {
 			if ref.OwnPrimaryKey {
@@ -91,9 +260,9 @@ func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 			}
 		}
 
-		identityMap, foreignValues = schema.GetIdentityFieldValuesMap(reflectValue, foreignFields)
+		identityMap, foreignValues = schema.GetIdentityFieldValuesMap(tx.Statement.Context, reflectValue, foreignFields)
 		if len(foreignValues) == 0 {
-			return
+			return nil
 		}
 	}
 
@@ -105,16 +274,26 @@ func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 	reflectResults := rel.FieldSchema.MakeSlice().Elem()
 	column, values := schema.ToQueryValues(clause.CurrentTable, relForeignKeys, foreignValues)
 
-	for _, cond := range conds {
-		if fc, ok := cond.(func(*gorm.DB) *gorm.DB); ok {
-			tx = fc(tx)
-		} else {
-			inlineConds = append(inlineConds, cond)
+	if len(values) != 0 {
+		tx = tx.Model(reflectResults.Addr().Interface()).Where(clause.IN{Column: column, Values: values})
+
+		for _, cond := range conds {
+			if fc, ok := cond.(func(*gorm.DB) *gorm.DB); ok {
+				tx = fc(tx)
+			} else {
+				inlineConds = append(inlineConds, cond)
+			}
+		}
+
+		if len(inlineConds) > 0 {
+			tx = tx.Where(inlineConds[0], inlineConds[1:]...)
+		}
+
+		if err := tx.Find(reflectResults.Addr().Interface()).Error; err != nil {
+			return err
 		}
 	}
 
-	db.AddError(tx.Where(clause.IN{Column: column, Values: values}).Find(reflectResults.Addr().Interface(), inlineConds...).Error)
-
 	fieldValues := make([]interface{}, len(relForeignFields))
 
 	// clean up old values before preloading
@@ -122,17 +301,17 @@ func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 	case reflect.Struct:
 		switch rel.Type {
 		case schema.HasMany, schema.Many2Many:
-			rel.Field.Set(reflectValue, reflect.MakeSlice(rel.Field.IndirectFieldType, 0, 10).Interface())
+			tx.AddError(rel.Field.Set(tx.Statement.Context, reflectValue, reflect.MakeSlice(rel.Field.IndirectFieldType, 0, 10).Interface()))
 		default:
-			rel.Field.Set(reflectValue, reflect.New(rel.Field.FieldType).Interface())
+			tx.AddError(rel.Field.Set(tx.Statement.Context, reflectValue, reflect.New(rel.Field.FieldType).Interface()))
 		}
 	case reflect.Slice, reflect.Array:
 		for i := 0; i < reflectValue.Len(); i++ {
 			switch rel.Type {
 			case schema.HasMany, schema.Many2Many:
-				rel.Field.Set(reflectValue.Index(i), reflect.MakeSlice(rel.Field.IndirectFieldType, 0, 10).Interface())
+				tx.AddError(rel.Field.Set(tx.Statement.Context, reflectValue.Index(i), reflect.MakeSlice(rel.Field.IndirectFieldType, 0, 10).Interface()))
 			default:
-				rel.Field.Set(reflectValue.Index(i), reflect.New(rel.Field.FieldType).Interface())
+				tx.AddError(rel.Field.Set(tx.Statement.Context, reflectValue.Index(i), reflect.New(rel.Field.FieldType).Interface()))
 			}
 		}
 	}
@@ -140,11 +319,16 @@ func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 	for i := 0; i < reflectResults.Len(); i++ {
 		elem := reflectResults.Index(i)
 		for idx, field := range relForeignFields {
-			fieldValues[idx], _ = field.ValueOf(elem)
+			fieldValues[idx], _ = field.ValueOf(tx.Statement.Context, elem)
 		}
 
-		for _, data := range identityMap[utils.ToStringKey(fieldValues...)] {
-			reflectFieldValue := rel.Field.ReflectValueOf(data)
+		datas, ok := identityMap[utils.ToStringKey(fieldValues...)]
+		if !ok {
+			return fmt.Errorf("failed to assign association %#v, make sure foreign fields exists", elem.Interface())
+		}
+
+		for _, data := range datas {
+			reflectFieldValue := rel.Field.ReflectValueOf(tx.Statement.Context, data)
 			if reflectFieldValue.Kind() == reflect.Ptr && reflectFieldValue.IsNil() {
 				reflectFieldValue.Set(reflect.New(rel.Field.FieldType.Elem()))
 			}
@@ -152,14 +336,16 @@ func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 			reflectFieldValue = reflect.Indirect(reflectFieldValue)
 			switch reflectFieldValue.Kind() {
 			case reflect.Struct:
-				rel.Field.Set(data, reflectResults.Index(i).Interface())
+				tx.AddError(rel.Field.Set(tx.Statement.Context, data, elem.Interface()))
 			case reflect.Slice, reflect.Array:
 				if reflectFieldValue.Type().Elem().Kind() == reflect.Ptr {
-					rel.Field.Set(data, reflect.Append(reflectFieldValue, elem).Interface())
+					tx.AddError(rel.Field.Set(tx.Statement.Context, data, reflect.Append(reflectFieldValue, elem).Interface()))
 				} else {
-					rel.Field.Set(data, reflect.Append(reflectFieldValue, elem.Elem()).Interface())
+					tx.AddError(rel.Field.Set(tx.Statement.Context, data, reflect.Append(reflectFieldValue, elem.Elem()).Interface()))
 				}
 			}
 		}
 	}
+
+	return tx.Error
 }

callbacks/query.go

@@ -3,11 +3,12 @@ package callbacks
 import (
 	"fmt"
 	"reflect"
-	"sort"
 	"strings"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
+	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils"
 )
 
 func Query(db *gorm.DB) {
@@ -20,28 +21,33 @@ func Query(db *gorm.DB) {
 				db.AddError(err)
 				return
 			}
-			defer rows.Close()
+			defer func() {
+				db.AddError(rows.Close())
+			}()
+			gorm.Scan(rows, db, 0)
 
-			gorm.Scan(rows, db, false)
+			if db.Statement.Result != nil {
+				db.Statement.Result.RowsAffected = db.RowsAffected
+			}
 		}
 	}
 }
 
 func BuildQuerySQL(db *gorm.DB) {
-	if db.Statement.Schema != nil && !db.Statement.Unscoped {
+	if db.Statement.Schema != nil {
 		for _, c := range db.Statement.Schema.QueryClauses {
 			db.Statement.AddClause(c)
 		}
 	}
 
-	if db.Statement.SQL.String() == "" {
+	if db.Statement.SQL.Len() == 0 {
 		db.Statement.SQL.Grow(100)
 		clauseSelect := clause.Select{Distinct: db.Statement.Distinct}
 
 		if db.Statement.ReflectValue.Kind() == reflect.Struct && db.Statement.ReflectValue.Type() == db.Statement.Schema.ModelType {
 			var conds []clause.Expression
 			for _, primaryField := range db.Statement.Schema.PrimaryFields {
-				if v, isZero := primaryField.ValueOf(db.Statement.ReflectValue); !isZero {
+				if v, isZero := primaryField.ValueOf(db.Statement.Context, db.Statement.ReflectValue); !isZero {
 					conds = append(conds, clause.Eq{Column: clause.Column{Table: db.Statement.Table, Name: primaryField.DBName}, Value: v})
 				}
 			}
@@ -95,127 +101,207 @@ func BuildQuerySQL(db *gorm.DB) {
 		}
 
 		// inline joins
-		if len(db.Statement.Joins) != 0 {
-			if len(db.Statement.Selects) == 0 && db.Statement.Schema != nil {
+		fromClause := clause.From{}
+		if v, ok := db.Statement.Clauses["FROM"].Expression.(clause.From); ok {
+			fromClause = v
+		}
+
+		if len(db.Statement.Joins) != 0 || len(fromClause.Joins) != 0 {
+			if len(db.Statement.Selects) == 0 && len(db.Statement.Omits) == 0 && db.Statement.Schema != nil {
 				clauseSelect.Columns = make([]clause.Column, len(db.Statement.Schema.DBNames))
 				for idx, dbName := range db.Statement.Schema.DBNames {
 					clauseSelect.Columns[idx] = clause.Column{Table: db.Statement.Table, Name: dbName}
 				}
 			}
 
-			joins := []clause.Join{}
-
-			if fromClause, ok := db.Statement.Clauses["FROM"].Expression.(clause.From); ok {
-				joins = fromClause.Joins
-			}
-
+			specifiedRelationsName := map[string]string{clause.CurrentTable: clause.CurrentTable}
 			for _, join := range db.Statement.Joins {
-				if db.Statement.Schema == nil {
-					joins = append(joins, clause.Join{
-						Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
-					})
-				} else if relation, ok := db.Statement.Schema.Relationships.Relations[join.Name]; ok {
-					tableAliasName := relation.Name
-
-					for _, s := range relation.FieldSchema.DBNames {
-						clauseSelect.Columns = append(clauseSelect.Columns, clause.Column{
-							Table: tableAliasName,
-							Name:  s,
-							Alias: tableAliasName + "__" + s,
-						})
-					}
-
-					exprs := make([]clause.Expression, len(relation.References))
-					for idx, ref := range relation.References {
-						if ref.OwnPrimaryKey {
-							exprs[idx] = clause.Eq{
-								Column: clause.Column{Table: clause.CurrentTable, Name: ref.PrimaryKey.DBName},
-								Value:  clause.Column{Table: tableAliasName, Name: ref.ForeignKey.DBName},
+				if db.Statement.Schema != nil {
+					var isRelations bool // is relations or raw sql
+					var relations []*schema.Relationship
+					relation, ok := db.Statement.Schema.Relationships.Relations[join.Name]
+					if ok {
+						isRelations = true
+						relations = append(relations, relation)
+					} else {
+						// handle nested join like "Manager.Company"
+						nestedJoinNames := strings.Split(join.Name, ".")
+						if len(nestedJoinNames) > 1 {
+							isNestedJoin := true
+							guessNestedRelations := make([]*schema.Relationship, 0, len(nestedJoinNames))
+							currentRelations := db.Statement.Schema.Relationships.Relations
+							for _, relname := range nestedJoinNames {
+								// incomplete match, only treated as raw sql
+								if relation, ok = currentRelations[relname]; ok {
+									guessNestedRelations = append(guessNestedRelations, relation)
+									currentRelations = relation.FieldSchema.Relationships.Relations
+								} else {
+									isNestedJoin = false
+									break
+								}
 							}
-						} else {
-							if ref.PrimaryValue == "" {
-								exprs[idx] = clause.Eq{
-									Column: clause.Column{Table: clause.CurrentTable, Name: ref.ForeignKey.DBName},
-									Value:  clause.Column{Table: tableAliasName, Name: ref.PrimaryKey.DBName},
-								}
-							} else {
-								exprs[idx] = clause.Eq{
-									Column: clause.Column{Table: tableAliasName, Name: ref.ForeignKey.DBName},
-									Value:  ref.PrimaryValue,
-								}
+
+							if isNestedJoin {
+								isRelations = true
+								relations = guessNestedRelations
 							}
 						}
 					}
 
-					joins = append(joins, clause.Join{
-						Type:  clause.LeftJoin,
-						Table: clause.Table{Name: relation.FieldSchema.Table, Alias: tableAliasName},
-						ON:    clause.Where{Exprs: exprs},
-					})
+					if isRelations {
+						genJoinClause := func(joinType clause.JoinType, tableAliasName string, parentTableName string, relation *schema.Relationship) clause.Join {
+							columnStmt := gorm.Statement{
+								Table: tableAliasName, DB: db, Schema: relation.FieldSchema,
+								Selects: join.Selects, Omits: join.Omits,
+							}
+
+							selectColumns, restricted := columnStmt.SelectAndOmitColumns(false, false)
+							for _, s := range relation.FieldSchema.DBNames {
+								if v, ok := selectColumns[s]; (ok && v) || (!ok && !restricted) {
+									clauseSelect.Columns = append(clauseSelect.Columns, clause.Column{
+										Table: tableAliasName,
+										Name:  s,
+										Alias: utils.NestedRelationName(tableAliasName, s),
+									})
+								}
+							}
+
+							if join.Expression != nil {
+								return clause.Join{
+									Type:       join.JoinType,
+									Expression: join.Expression,
+								}
+							}
+
+							exprs := make([]clause.Expression, len(relation.References))
+							for idx, ref := range relation.References {
+								if ref.OwnPrimaryKey {
+									exprs[idx] = clause.Eq{
+										Column: clause.Column{Table: parentTableName, Name: ref.PrimaryKey.DBName},
+										Value:  clause.Column{Table: tableAliasName, Name: ref.ForeignKey.DBName},
+									}
+								} else {
+									if ref.PrimaryValue == "" {
+										exprs[idx] = clause.Eq{
+											Column: clause.Column{Table: parentTableName, Name: ref.ForeignKey.DBName},
+											Value:  clause.Column{Table: tableAliasName, Name: ref.PrimaryKey.DBName},
+										}
+									} else {
+										exprs[idx] = clause.Eq{
+											Column: clause.Column{Table: tableAliasName, Name: ref.ForeignKey.DBName},
+											Value:  ref.PrimaryValue,
+										}
+									}
+								}
+							}
+
+							{
+								onStmt := gorm.Statement{Table: tableAliasName, DB: db, Clauses: map[string]clause.Clause{}}
+								for _, c := range relation.FieldSchema.QueryClauses {
+									onStmt.AddClause(c)
+								}
+
+								if join.On != nil {
+									onStmt.AddClause(join.On)
+								}
+
+								if cs, ok := onStmt.Clauses["WHERE"]; ok {
+									if where, ok := cs.Expression.(clause.Where); ok {
+										where.Build(&onStmt)
+
+										if onSQL := onStmt.SQL.String(); onSQL != "" {
+											vars := onStmt.Vars
+											for idx, v := range vars {
+												bindvar := strings.Builder{}
+												onStmt.Vars = vars[0 : idx+1]
+												db.Dialector.BindVarTo(&bindvar, &onStmt, v)
+												onSQL = strings.Replace(onSQL, bindvar.String(), "?", 1)
+											}
+
+											exprs = append(exprs, clause.Expr{SQL: onSQL, Vars: vars})
+										}
+									}
+								}
+							}
+
+							return clause.Join{
+								Type:  joinType,
+								Table: clause.Table{Name: relation.FieldSchema.Table, Alias: tableAliasName},
+								ON:    clause.Where{Exprs: exprs},
+							}
+						}
+
+						parentTableName := clause.CurrentTable
+						for idx, rel := range relations {
+							// joins table alias like "Manager, Company, Manager__Company"
+							curAliasName := rel.Name
+							if parentTableName != clause.CurrentTable {
+								curAliasName = utils.NestedRelationName(parentTableName, curAliasName)
+							}
+
+							if _, ok := specifiedRelationsName[curAliasName]; !ok {
+								aliasName := curAliasName
+								if idx == len(relations)-1 && join.Alias != "" {
+									aliasName = join.Alias
+								}
+
+								fromClause.Joins = append(fromClause.Joins, genJoinClause(join.JoinType, aliasName, specifiedRelationsName[parentTableName], rel))
+								specifiedRelationsName[curAliasName] = aliasName
+							}
+
+							parentTableName = curAliasName
+						}
+					} else {
+						fromClause.Joins = append(fromClause.Joins, clause.Join{
+							Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
+						})
+					}
 				} else {
-					joins = append(joins, clause.Join{
+					fromClause.Joins = append(fromClause.Joins, clause.Join{
 						Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
 					})
 				}
 			}
 
-			db.Statement.Joins = nil
-			db.Statement.AddClause(clause.From{Joins: joins})
+			db.Statement.AddClause(fromClause)
 		} else {
 			db.Statement.AddClauseIfNotExists(clause.From{})
 		}
 
 		db.Statement.AddClauseIfNotExists(clauseSelect)
 
-		db.Statement.Build("SELECT", "FROM", "WHERE", "GROUP BY", "ORDER BY", "LIMIT", "FOR")
+		db.Statement.Build(db.Statement.BuildClauses...)
 	}
 }
 
 func Preload(db *gorm.DB) {
 	if db.Error == nil && len(db.Statement.Preloads) > 0 {
-		preloadMap := map[string]map[string][]interface{}{}
-		for name := range db.Statement.Preloads {
-			preloadFields := strings.Split(name, ".")
-			if preloadFields[0] == clause.Associations {
-				for _, rel := range db.Statement.Schema.Relationships.Relations {
-					if rel.Schema == db.Statement.Schema {
-						if _, ok := preloadMap[rel.Name]; !ok {
-							preloadMap[rel.Name] = map[string][]interface{}{}
-						}
-
-						if value := strings.TrimPrefix(strings.TrimPrefix(name, preloadFields[0]), "."); value != "" {
-							preloadMap[rel.Name][value] = db.Statement.Preloads[name]
-						}
-					}
-				}
-			} else {
-				if _, ok := preloadMap[preloadFields[0]]; !ok {
-					preloadMap[preloadFields[0]] = map[string][]interface{}{}
-				}
-
-				if value := strings.TrimPrefix(strings.TrimPrefix(name, preloadFields[0]), "."); value != "" {
-					preloadMap[preloadFields[0]][value] = db.Statement.Preloads[name]
-				}
-			}
+		if db.Statement.Schema == nil {
+			db.AddError(fmt.Errorf("%w when using preload", gorm.ErrModelValueRequired))
+			return
 		}
 
-		preloadNames := make([]string, 0, len(preloadMap))
-		for key := range preloadMap {
-			preloadNames = append(preloadNames, key)
+		joins := make([]string, 0, len(db.Statement.Joins))
+		for _, join := range db.Statement.Joins {
+			joins = append(joins, join.Name)
 		}
-		sort.Strings(preloadNames)
 
-		for _, name := range preloadNames {
-			if rel := db.Statement.Schema.Relationships.Relations[name]; rel != nil {
-				preload(db, rel, db.Statement.Preloads[name], preloadMap[name])
-			} else {
-				db.AddError(fmt.Errorf("%v: %w for schema %v", name, gorm.ErrUnsupportedRelation, db.Statement.Schema.Name))
-			}
+		tx := preloadDB(db, db.Statement.ReflectValue, db.Statement.Dest)
+		if tx.Error != nil {
+			return
 		}
+
+		db.AddError(preloadEntryPoint(tx, joins, &tx.Statement.Schema.Relationships, db.Statement.Preloads, db.Statement.Preloads[clause.Associations]))
 	}
 }
 
 func AfterQuery(db *gorm.DB) {
+	// clear the joins after query because preload need it
+	if v, ok := db.Statement.Clauses["FROM"].Expression.(clause.From); ok {
+		fromClause := db.Statement.Clauses["FROM"]
+		fromClause.Expression = clause.From{Tables: v.Tables, Joins: utils.RTrimSlice(v.Joins, len(db.Statement.Joins))} // keep the original From Joins
+		db.Statement.Clauses["FROM"] = fromClause
+	}
 	if db.Error == nil && db.Statement.Schema != nil && !db.Statement.SkipHooks && db.Statement.Schema.AfterFind && db.RowsAffected > 0 {
 		callMethod(db, func(value interface{}, tx *gorm.DB) bool {
 			if i, ok := value.(AfterFindInterface); ok {

callbacks/raw.go

@@ -9,8 +9,14 @@ func RawExec(db *gorm.DB) {
 		result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
 		if err != nil {
 			db.AddError(err)
-		} else {
-			db.RowsAffected, _ = result.RowsAffected()
+			return
+		}
+
+		db.RowsAffected, _ = result.RowsAffected()
+
+		if db.Statement.Result != nil {
+			db.Statement.Result.Result = result
+			db.Statement.Result.RowsAffected = db.RowsAffected
 		}
 	}
 }

callbacks/row.go

@@ -7,15 +7,17 @@ import (
 func RowQuery(db *gorm.DB) {
 	if db.Error == nil {
 		BuildQuerySQL(db)
-
-		if !db.DryRun {
-			if isRows, ok := db.InstanceGet("rows"); ok && isRows.(bool) {
-				db.Statement.Dest, db.Error = db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
-			} else {
-				db.Statement.Dest = db.Statement.ConnPool.QueryRowContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
-			}
-
-			db.RowsAffected = -1
+		if db.DryRun || db.Error != nil {
+			return
 		}
+
+		if isRows, ok := db.Get("rows"); ok && isRows.(bool) {
+			db.Statement.Settings.Delete("rows")
+			db.Statement.Dest, db.Error = db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+		} else {
+			db.Statement.Dest = db.Statement.ConnPool.QueryRowContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+		}
+
+		db.RowsAffected = -1
 	}
 }

callbacks/transaction.go

@@ -5,12 +5,14 @@ import (
 )
 
 func BeginTransaction(db *gorm.DB) {
-	if !db.Config.SkipDefaultTransaction {
+	if !db.Config.SkipDefaultTransaction && db.Error == nil {
 		if tx := db.Begin(); tx.Error == nil {
 			db.Statement.ConnPool = tx.Statement.ConnPool
 			db.InstanceSet("gorm:started_transaction", true)
 		} else if tx.Error == gorm.ErrInvalidTransaction {
 			tx.Error = nil
+		} else {
+			db.Error = tx.Error
 		}
 	}
 }
@@ -18,11 +20,12 @@ func BeginTransaction(db *gorm.DB) {
 func CommitOrRollbackTransaction(db *gorm.DB) {
 	if !db.Config.SkipDefaultTransaction {
 		if _, ok := db.InstanceGet("gorm:started_transaction"); ok {
-			if db.Error == nil {
-				db.Commit()
-			} else {
+			if db.Error != nil {
 				db.Rollback()
+			} else {
+				db.Commit()
 			}
+
 			db.Statement.ConnPool = db.ConnPool
 		}
 	}

callbacks/update.go

@@ -7,6 +7,7 @@ import (
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils"
 )
 
 func SetupUpdateReflectValue(db *gorm.DB) {
@@ -20,7 +21,7 @@ func SetupUpdateReflectValue(db *gorm.DB) {
 			if dest, ok := db.Statement.Dest.(map[string]interface{}); ok {
 				for _, rel := range db.Statement.Schema.Relationships.BelongsTo {
 					if _, ok := dest[rel.Name]; ok {
-						rel.Field.Set(db.Statement.ReflectValue, dest[rel.Name])
+						db.AddError(rel.Field.Set(db.Statement.Context, db.Statement.ReflectValue, dest[rel.Name]))
 					}
 				}
 			}
@@ -28,6 +29,7 @@ func SetupUpdateReflectValue(db *gorm.DB) {
 	}
 }
 
+// BeforeUpdate before update hooks
 func BeforeUpdate(db *gorm.DB) {
 	if db.Error == nil && db.Statement.Schema != nil && !db.Statement.SkipHooks && (db.Statement.Schema.BeforeSave || db.Statement.Schema.BeforeUpdate) {
 		callMethod(db, func(value interface{}, tx *gorm.DB) (called bool) {
@@ -50,45 +52,78 @@ func BeforeUpdate(db *gorm.DB) {
 	}
 }
 
-func Update(db *gorm.DB) {
-	if db.Error == nil {
-		if db.Statement.Schema != nil && !db.Statement.Unscoped {
+// Update update hook
+func Update(config *Config) func(db *gorm.DB) {
+	supportReturning := utils.Contains(config.UpdateClauses, "RETURNING")
+
+	return func(db *gorm.DB) {
+		if db.Error != nil {
+			return
+		}
+
+		if db.Statement.Schema != nil {
 			for _, c := range db.Statement.Schema.UpdateClauses {
 				db.Statement.AddClause(c)
 			}
 		}
 
-		if db.Statement.SQL.String() == "" {
+		if db.Statement.SQL.Len() == 0 {
 			db.Statement.SQL.Grow(180)
 			db.Statement.AddClauseIfNotExists(clause.Update{})
-			if set := ConvertToAssignments(db.Statement); len(set) != 0 {
-				db.Statement.AddClause(set)
-			} else {
-				return
+			if _, ok := db.Statement.Clauses["SET"]; !ok {
+				if set := ConvertToAssignments(db.Statement); len(set) != 0 {
+					defer delete(db.Statement.Clauses, "SET")
+					db.Statement.AddClause(set)
+				} else {
+					return
+				}
 			}
-			db.Statement.Build("UPDATE", "SET", "WHERE")
+
+			db.Statement.Build(db.Statement.BuildClauses...)
 		}
 
-		if _, ok := db.Statement.Clauses["WHERE"]; !db.AllowGlobalUpdate && !ok {
-			db.AddError(gorm.ErrMissingWhereClause)
-			return
-		}
+		checkMissingWhereConditions(db)
 
 		if !db.DryRun && db.Error == nil {
-			result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+			if ok, mode := hasReturning(db, supportReturning); ok {
+				if rows, err := db.Statement.ConnPool.QueryContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...); db.AddError(err) == nil {
+					dest := db.Statement.Dest
+					db.Statement.Dest = db.Statement.ReflectValue.Addr().Interface()
+					gorm.Scan(rows, db, mode)
+					db.Statement.Dest = dest
+					db.AddError(rows.Close())
 
-			if err == nil {
-				db.RowsAffected, _ = result.RowsAffected()
+					if db.Statement.Result != nil {
+						db.Statement.Result.RowsAffected = db.RowsAffected
+					}
+				}
 			} else {
-				db.AddError(err)
+				result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
+
+				if db.AddError(err) == nil {
+					db.RowsAffected, _ = result.RowsAffected()
+				}
+
+				if db.Statement.Result != nil {
+					db.Statement.Result.Result = result
+					db.Statement.Result.RowsAffected = db.RowsAffected
+				}
 			}
 		}
 	}
 }
 
+// AfterUpdate after update hooks
 func AfterUpdate(db *gorm.DB) {
 	if db.Error == nil && db.Statement.Schema != nil && !db.Statement.SkipHooks && (db.Statement.Schema.AfterSave || db.Statement.Schema.AfterUpdate) {
 		callMethod(db, func(value interface{}, tx *gorm.DB) (called bool) {
+			if db.Statement.Schema.AfterUpdate {
+				if i, ok := value.(AfterUpdateInterface); ok {
+					called = true
+					db.AddError(i.AfterUpdate(tx))
+				}
+			}
+
 			if db.Statement.Schema.AfterSave {
 				if i, ok := value.(AfterSaveInterface); ok {
 					called = true
@@ -96,12 +131,6 @@ func AfterUpdate(db *gorm.DB) {
 				}
 			}
 
-			if db.Statement.Schema.AfterUpdate {
-				if i, ok := value.(AfterUpdateInterface); ok {
-					called = true
-					db.AddError(i.AfterUpdate(tx))
-				}
-			}
 			return called
 		})
 	}
@@ -118,13 +147,15 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 	case reflect.Slice, reflect.Array:
 		assignValue = func(field *schema.Field, value interface{}) {
 			for i := 0; i < stmt.ReflectValue.Len(); i++ {
-				field.Set(stmt.ReflectValue.Index(i), value)
+				if stmt.ReflectValue.CanAddr() {
+					field.Set(stmt.Context, stmt.ReflectValue.Index(i), value)
+				}
 			}
 		}
 	case reflect.Struct:
 		assignValue = func(field *schema.Field, value interface{}) {
 			if stmt.ReflectValue.CanAddr() {
-				field.Set(stmt.ReflectValue, value)
+				field.Set(stmt.Context, stmt.ReflectValue, value)
 			}
 		}
 	default:
@@ -140,23 +171,26 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 	if !updatingValue.CanAddr() || stmt.Dest != stmt.Model {
 		switch stmt.ReflectValue.Kind() {
 		case reflect.Slice, reflect.Array:
-			var primaryKeyExprs []clause.Expression
-			for i := 0; i < stmt.ReflectValue.Len(); i++ {
-				var exprs = make([]clause.Expression, len(stmt.Schema.PrimaryFields))
-				var notZero bool
-				for idx, field := range stmt.Schema.PrimaryFields {
-					value, isZero := field.ValueOf(stmt.ReflectValue.Index(i))
-					exprs[idx] = clause.Eq{Column: field.DBName, Value: value}
-					notZero = notZero || !isZero
+			if size := stmt.ReflectValue.Len(); size > 0 {
+				var isZero bool
+				for i := 0; i < size; i++ {
+					for _, field := range stmt.Schema.PrimaryFields {
+						_, isZero = field.ValueOf(stmt.Context, stmt.ReflectValue.Index(i))
+						if !isZero {
+							break
+						}
+					}
 				}
-				if notZero {
-					primaryKeyExprs = append(primaryKeyExprs, clause.And(exprs...))
+
+				if !isZero {
+					_, primaryValues := schema.GetIdentityFieldValuesMap(stmt.Context, stmt.ReflectValue, stmt.Schema.PrimaryFields)
+					column, values := schema.ToQueryValues("", stmt.Schema.PrimaryFieldDBNames, primaryValues)
+					stmt.AddClause(clause.Where{Exprs: []clause.Expression{clause.IN{Column: column, Values: values}}})
 				}
 			}
-			stmt.AddClause(clause.Where{Exprs: []clause.Expression{clause.Or(primaryKeyExprs...)}})
 		case reflect.Struct:
 			for _, field := range stmt.Schema.PrimaryFields {
-				if value, isZero := field.ValueOf(stmt.ReflectValue); !isZero {
+				if value, isZero := field.ValueOf(stmt.Context, stmt.ReflectValue); !isZero {
 					stmt.AddClause(clause.Where{Exprs: []clause.Expression{clause.Eq{Column: field.DBName, Value: value}}})
 				}
 			}
@@ -209,46 +243,64 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 						if field.AutoUpdateTime == schema.UnixNanosecond {
 							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now.UnixNano()})
 						} else if field.AutoUpdateTime == schema.UnixMillisecond {
-							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now.UnixNano() / 1e6})
-						} else if field.GORMDataType == schema.Time {
-							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now})
-						} else {
+							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now.UnixMilli()})
+						} else if field.AutoUpdateTime == schema.UnixSecond {
 							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now.Unix()})
+						} else {
+							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: now})
 						}
 					}
 				}
 			}
 		}
 	default:
+		updatingSchema := stmt.Schema
+		var isDiffSchema bool
+		if !updatingValue.CanAddr() || stmt.Dest != stmt.Model {
+			// different schema
+			updatingStmt := &gorm.Statement{DB: stmt.DB}
+			if err := updatingStmt.Parse(stmt.Dest); err == nil {
+				updatingSchema = updatingStmt.Schema
+				isDiffSchema = true
+			}
+		}
+
 		switch updatingValue.Kind() {
 		case reflect.Struct:
 			set = make([]clause.Assignment, 0, len(stmt.Schema.FieldsByDBName))
 			for _, dbName := range stmt.Schema.DBNames {
-				field := stmt.Schema.LookUpField(dbName)
-				if !field.PrimaryKey || (!updatingValue.CanAddr() || stmt.Dest != stmt.Model) {
-					if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && (!restricted || (!stmt.SkipHooks && field.AutoUpdateTime > 0))) {
-						value, isZero := field.ValueOf(updatingValue)
-						if !stmt.SkipHooks && field.AutoUpdateTime > 0 {
-							if field.AutoUpdateTime == schema.UnixNanosecond {
-								value = stmt.DB.NowFunc().UnixNano()
-							} else if field.AutoUpdateTime == schema.UnixMillisecond {
-								value = stmt.DB.NowFunc().UnixNano() / 1e6
-							} else if field.GORMDataType == schema.Time {
-								value = stmt.DB.NowFunc()
-							} else {
-								value = stmt.DB.NowFunc().Unix()
+				if field := updatingSchema.LookUpField(dbName); field != nil {
+					if !field.PrimaryKey || !updatingValue.CanAddr() || stmt.Dest != stmt.Model {
+						if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && (!restricted || (!stmt.SkipHooks && field.AutoUpdateTime > 0))) {
+							value, isZero := field.ValueOf(stmt.Context, updatingValue)
+							if !stmt.SkipHooks && field.AutoUpdateTime > 0 {
+								if field.AutoUpdateTime == schema.UnixNanosecond {
+									value = stmt.DB.NowFunc().UnixNano()
+								} else if field.AutoUpdateTime == schema.UnixMillisecond {
+									value = stmt.DB.NowFunc().UnixMilli()
+								} else if field.AutoUpdateTime == schema.UnixSecond {
+									value = stmt.DB.NowFunc().Unix()
+								} else {
+									value = stmt.DB.NowFunc()
+								}
+								isZero = false
 							}
-							isZero = false
-						}
 
-						if ok || !isZero {
-							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: value})
-							assignValue(field, value)
+							if (ok || !isZero) && field.Updatable {
+								set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: value})
+								assignField := field
+								if isDiffSchema {
+									if originField := stmt.Schema.LookUpField(dbName); originField != nil {
+										assignField = originField
+									}
+								}
+								assignValue(assignField, value)
+							}
+						}
+					} else {
+						if value, isZero := field.ValueOf(stmt.Context, updatingValue); !isZero {
+							stmt.AddClause(clause.Where{Exprs: []clause.Expression{clause.Eq{Column: field.DBName, Value: value}}})
 						}
-					}
-				} else {
-					if value, isZero := field.ValueOf(updatingValue); !isZero {
-						stmt.AddClause(clause.Where{Exprs: []clause.Expression{clause.Eq{Column: field.DBName, Value: value}}})
 					}
 				}
 			}

chainable_api.go

@@ -10,10 +10,11 @@ import (
 )
 
 // Model specify the model you would like to run db operations
-//    // update all users's name to `hello`
-//    db.Model(&User{}).Update("name", "hello")
-//    // if user's primary key is non-blank, will use it as condition, then will only update the user's name to `hello`
-//    db.Model(&user).Update("name", "hello")
+//
+//	// update all users's name to `hello`
+//	db.Model(&User{}).Update("name", "hello")
+//	// if user's primary key is non-blank, will use it as condition, then will only update that user's name to `hello`
+//	db.Model(&user).Update("name", "hello")
 func (db *DB) Model(value interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Model = value
@@ -21,6 +22,19 @@ func (db *DB) Model(value interface{}) (tx *DB) {
 }
 
 // Clauses Add clauses
+//
+// This supports both standard clauses (clause.OrderBy, clause.Limit, clause.Where) and more
+// advanced techniques like specifying lock strength and optimizer hints. See the
+// [docs] for more depth.
+//
+//	// add a simple limit clause
+//	db.Clauses(clause.Limit{Limit: 1}).Find(&User{})
+//	// tell the optimizer to use the `idx_user_name` index
+//	db.Clauses(hints.UseIndex("idx_user_name")).Find(&User{})
+//	// specify the lock strength to UPDATE
+//	db.Clauses(clause.Locking{Strength: "UPDATE"}).Find(&users)
+//
+// [docs]: https://gorm.io/docs/sql_builder.html#Clauses
 func (db *DB) Clauses(conds ...clause.Expression) (tx *DB) {
 	tx = db.getInstance()
 	var whereConds []interface{}
@@ -41,28 +55,42 @@ func (db *DB) Clauses(conds ...clause.Expression) (tx *DB) {
 	return
 }
 
-var tableRegexp = regexp.MustCompile(`(?i).+? AS (\w+)\s*(?:$|,)`)
+var tableRegexp = regexp.MustCompile(`(?i)(?:.+? AS (\w+)\s*(?:$|,)|^\w+\s+(\w+)$)`)
 
 // Table specify the table you would like to run db operations
+//
+//	// Get a user
+//	db.Table("users").Take(&result)
 func (db *DB) Table(name string, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	if strings.Contains(name, " ") || strings.Contains(name, "`") || len(args) > 0 {
 		tx.Statement.TableExpr = &clause.Expr{SQL: name, Vars: args}
-		if results := tableRegexp.FindStringSubmatch(name); len(results) == 2 {
-			tx.Statement.Table = results[1]
-			return
+		if results := tableRegexp.FindStringSubmatch(name); len(results) == 3 {
+			if results[1] != "" {
+				tx.Statement.Table = results[1]
+			} else {
+				tx.Statement.Table = results[2]
+			}
 		}
 	} else if tables := strings.Split(name, "."); len(tables) == 2 {
 		tx.Statement.TableExpr = &clause.Expr{SQL: tx.Statement.Quote(name)}
 		tx.Statement.Table = tables[1]
-		return
+	} else if name != "" {
+		tx.Statement.TableExpr = &clause.Expr{SQL: tx.Statement.Quote(name)}
+		tx.Statement.Table = name
+	} else {
+		tx.Statement.TableExpr = nil
+		tx.Statement.Table = ""
 	}
-
-	tx.Statement.Table = name
 	return
 }
 
 // Distinct specify distinct fields that you want querying
+//
+//	// Select distinct names of users
+//	db.Distinct("name").Find(&results)
+//	// Select distinct name/age pairs from users
+//	db.Distinct("name", "age").Find(&results)
 func (db *DB) Distinct(args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Distinct = true
@@ -73,6 +101,14 @@ func (db *DB) Distinct(args ...interface{}) (tx *DB) {
 }
 
 // Select specify fields that you want when querying, creating, updating
+//
+// Use Select when you only want a subset of the fields. By default, GORM will select all fields.
+// Select accepts both string arguments and arrays.
+//
+//	// Select name and age of user using multiple arguments
+//	db.Select("name", "age").Find(&users)
+//	// Select name and age of user using an array
+//	db.Select([]string{"name", "age"}).Find(&users)
 func (db *DB) Select(query interface{}, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 
@@ -91,7 +127,11 @@ func (db *DB) Select(query interface{}, args ...interface{}) (tx *DB) {
 				return
 			}
 		}
-		delete(tx.Statement.Clauses, "SELECT")
+
+		if clause, ok := tx.Statement.Clauses["SELECT"]; ok {
+			clause.Expression = nil
+			tx.Statement.Clauses["SELECT"] = clause
+		}
 	case string:
 		if strings.Count(v, "?") >= len(args) && len(args) > 0 {
 			tx.Statement.AddClause(clause.Select{
@@ -103,7 +143,7 @@ func (db *DB) Select(query interface{}, args ...interface{}) (tx *DB) {
 				Distinct:   db.Statement.Distinct,
 				Expression: clause.NamedExpr{SQL: v, Vars: args},
 			})
-		}  else {
+		} else {
 			tx.Statement.Selects = []string{v}
 
 			for _, arg := range args {
@@ -121,7 +161,10 @@ func (db *DB) Select(query interface{}, args ...interface{}) (tx *DB) {
 				}
 			}
 
-			delete(tx.Statement.Clauses, "SELECT")
+			if clause, ok := tx.Statement.Clauses["SELECT"]; ok {
+				clause.Expression = nil
+				tx.Statement.Clauses["SELECT"] = clause
+			}
 		}
 	default:
 		tx.AddError(fmt.Errorf("unsupported select args %v %v", query, args))
@@ -142,7 +185,25 @@ func (db *DB) Omit(columns ...string) (tx *DB) {
 	return
 }
 
+// MapColumns modify the column names in the query results to facilitate align to the corresponding structural fields
+func (db *DB) MapColumns(m map[string]string) (tx *DB) {
+	tx = db.getInstance()
+	tx.Statement.ColumnMapping = m
+	return
+}
+
 // Where add conditions
+//
+// See the [docs] for details on the various formats that where clauses can take. By default, where clauses chain with AND.
+//
+//	// Find the first user with name jinzhu
+//	db.Where("name = ?", "jinzhu").First(&user)
+//	// Find the first user with name jinzhu and age 20
+//	db.Where(&User{Name: "jinzhu", Age: 20}).First(&user)
+//	// Find the first user with name jinzhu and age not equal to 20
+//	db.Where("name = ?", "jinzhu").Where("age <> ?", "20").First(&user)
+//
+// [docs]: https://gorm.io/docs/query.html#Conditions
 func (db *DB) Where(query interface{}, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	if conds := tx.Statement.BuildCondition(query, args...); len(conds) > 0 {
@@ -152,6 +213,11 @@ func (db *DB) Where(query interface{}, args ...interface{}) (tx *DB) {
 }
 
 // Not add NOT conditions
+//
+// Not works similarly to where, and has the same syntax.
+//
+//	// Find the first user with name not equal to jinzhu
+//	db.Not("name = ?", "jinzhu").First(&user)
 func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	if conds := tx.Statement.BuildCondition(query, args...); len(conds) > 0 {
@@ -161,6 +227,11 @@ func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) {
 }
 
 // Or add OR conditions
+//
+// Or is used to chain together queries with an OR.
+//
+//	// Find the first user with name equal to jinzhu or john
+//	db.Where("name = ?", "jinzhu").Or("name = ?", "john").First(&user)
 func (db *DB) Or(query interface{}, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	if conds := tx.Statement.BuildCondition(query, args...); len(conds) > 0 {
@@ -170,15 +241,45 @@ func (db *DB) Or(query interface{}, args ...interface{}) (tx *DB) {
 }
 
 // Joins specify Joins conditions
-//     db.Joins("Account").Find(&user)
-//     db.Joins("JOIN emails ON emails.user_id = users.id AND emails.email = ?", "jinzhu@example.org").Find(&user)
+//
+//	db.Joins("Account").Find(&user)
+//	db.Joins("JOIN emails ON emails.user_id = users.id AND emails.email = ?", "jinzhu@example.org").Find(&user)
+//	db.Joins("Account", DB.Select("id").Where("user_id = users.id AND name = ?", "someName").Model(&Account{}))
 func (db *DB) Joins(query string, args ...interface{}) (tx *DB) {
+	return joins(db, clause.LeftJoin, query, args...)
+}
+
+// InnerJoins specify inner joins conditions
+// db.InnerJoins("Account").Find(&user)
+func (db *DB) InnerJoins(query string, args ...interface{}) (tx *DB) {
+	return joins(db, clause.InnerJoin, query, args...)
+}
+
+func joins(db *DB, joinType clause.JoinType, query string, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
-	tx.Statement.Joins = append(tx.Statement.Joins, join{Name: query, Conds: args})
+
+	if len(args) == 1 {
+		if db, ok := args[0].(*DB); ok {
+			j := join{
+				Name: query, Conds: args, Selects: db.Statement.Selects,
+				Omits: db.Statement.Omits, JoinType: joinType,
+			}
+			if where, ok := db.Statement.Clauses["WHERE"].Expression.(clause.Where); ok {
+				j.On = &where
+			}
+			tx.Statement.Joins = append(tx.Statement.Joins, j)
+			return
+		}
+	}
+
+	tx.Statement.Joins = append(tx.Statement.Joins, join{Name: query, Conds: args, JoinType: joinType})
 	return
 }
 
 // Group specify the group method on the find
+//
+//	// Select the sum age of users with given names
+//	db.Model(&User{}).Select("name, sum(age) as total").Group("name").Find(&results)
 func (db *DB) Group(name string) (tx *DB) {
 	tx = db.getInstance()
 
@@ -190,6 +291,9 @@ func (db *DB) Group(name string) (tx *DB) {
 }
 
 // Having specify HAVING conditions for GROUP BY
+//
+//	// Select the sum age of users with name jinzhu
+//	db.Model(&User{}).Select("name, sum(age) as total").Group("name").Having("name = ?", "jinzhu").Find(&result)
 func (db *DB) Having(query interface{}, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.AddClause(clause.GroupBy{
@@ -198,35 +302,58 @@ func (db *DB) Having(query interface{}, args ...interface{}) (tx *DB) {
 	return
 }
 
-// Order specify order when retrieve records from database
-//     db.Order("name DESC")
-//     db.Order(clause.OrderByColumn{Column: clause.Column{Name: "name"}, Desc: true})
+// Order specify order when retrieving records from database
+//
+//	db.Order("name DESC")
+//	db.Order(clause.OrderByColumn{Column: clause.Column{Name: "name"}, Desc: true})
+//	db.Order(clause.OrderBy{Columns: []clause.OrderByColumn{
+//		{Column: clause.Column{Name: "name"}, Desc: true},
+//		{Column: clause.Column{Name: "age"}, Desc: true},
+//	}})
 func (db *DB) Order(value interface{}) (tx *DB) {
 	tx = db.getInstance()
 
 	switch v := value.(type) {
+	case clause.OrderBy:
+		tx.Statement.AddClause(v)
 	case clause.OrderByColumn:
 		tx.Statement.AddClause(clause.OrderBy{
 			Columns: []clause.OrderByColumn{v},
 		})
-	default:
-		tx.Statement.AddClause(clause.OrderBy{
-			Columns: []clause.OrderByColumn{{
-				Column: clause.Column{Name: fmt.Sprint(value), Raw: true},
-			}},
-		})
+	case string:
+		if v != "" {
+			tx.Statement.AddClause(clause.OrderBy{
+				Columns: []clause.OrderByColumn{{
+					Column: clause.Column{Name: v, Raw: true},
+				}},
+			})
+		}
 	}
 	return
 }
 
 // Limit specify the number of records to be retrieved
+//
+// Limit conditions can be cancelled by using `Limit(-1)`.
+//
+//	// retrieve 3 users
+//	db.Limit(3).Find(&users)
+//	// retrieve 3 users into users1, and all users into users2
+//	db.Limit(3).Find(&users1).Limit(-1).Find(&users2)
 func (db *DB) Limit(limit int) (tx *DB) {
 	tx = db.getInstance()
-	tx.Statement.AddClause(clause.Limit{Limit: limit})
+	tx.Statement.AddClause(clause.Limit{Limit: &limit})
 	return
 }
 
 // Offset specify the number of records to skip before starting to return the records
+//
+// Offset conditions can be cancelled by using `Offset(-1)`.
+//
+//	// select the third user
+//	db.Offset(2).First(&user)
+//	// select the first user by cancelling an earlier chained offset
+//	db.Offset(5).Offset(-1).First(&user)
 func (db *DB) Offset(offset int) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.AddClause(clause.Limit{Offset: offset})
@@ -234,25 +361,37 @@ func (db *DB) Offset(offset int) (tx *DB) {
 }
 
 // Scopes pass current database connection to arguments `func(DB) DB`, which could be used to add conditions dynamically
-//     func AmountGreaterThan1000(db *gorm.DB) *gorm.DB {
-//         return db.Where("amount > ?", 1000)
-//     }
 //
-//     func OrderStatus(status []string) func (db *gorm.DB) *gorm.DB {
-//         return func (db *gorm.DB) *gorm.DB {
-//             return db.Scopes(AmountGreaterThan1000).Where("status in (?)", status)
-//         }
-//     }
+//	func AmountGreaterThan1000(db *gorm.DB) *gorm.DB {
+//	    return db.Where("amount > ?", 1000)
+//	}
 //
-//     db.Scopes(AmountGreaterThan1000, OrderStatus([]string{"paid", "shipped"})).Find(&orders)
+//	func OrderStatus(status []string) func (db *gorm.DB) *gorm.DB {
+//	    return func (db *gorm.DB) *gorm.DB {
+//	        return db.Scopes(AmountGreaterThan1000).Where("status in (?)", status)
+//	    }
+//	}
+//
+//	db.Scopes(AmountGreaterThan1000, OrderStatus([]string{"paid", "shipped"})).Find(&orders)
 func (db *DB) Scopes(funcs ...func(*DB) *DB) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.scopes = append(tx.Statement.scopes, funcs...)
 	return tx
 }
 
+func (db *DB) executeScopes() (tx *DB) {
+	scopes := db.Statement.scopes
+	db.Statement.scopes = nil
+	for _, scope := range scopes {
+		db = scope(db)
+	}
+	return db
+}
+
 // Preload preload associations with given conditions
-//    db.Preload("Orders", "state NOT IN (?)", "cancelled").Find(&users)
+//
+//	// get all users, and preload all non-cancelled orders
+//	db.Preload("Orders", "state NOT IN (?)", "cancelled").Find(&users)
 func (db *DB) Preload(query string, args ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	if tx.Statement.Preloads == nil {
@@ -262,18 +401,57 @@ func (db *DB) Preload(query string, args ...interface{}) (tx *DB) {
 	return
 }
 
+// Attrs provide attributes used in [FirstOrCreate] or [FirstOrInit]
+//
+// Attrs only adds attributes if the record is not found.
+//
+//	// assign an email if the record is not found
+//	db.Where(User{Name: "non_existing"}).Attrs(User{Email: "fake@fake.org"}).FirstOrInit(&user)
+//	// user -> User{Name: "non_existing", Email: "fake@fake.org"}
+//
+//	// assign an email if the record is not found, otherwise ignore provided email
+//	db.Where(User{Name: "jinzhu"}).Attrs(User{Email: "fake@fake.org"}).FirstOrInit(&user)
+//	// user -> User{Name: "jinzhu", Age: 20}
+//
+// [FirstOrCreate]: https://gorm.io/docs/advanced_query.html#FirstOrCreate
+// [FirstOrInit]: https://gorm.io/docs/advanced_query.html#FirstOrInit
 func (db *DB) Attrs(attrs ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.attrs = attrs
 	return
 }
 
+// Assign provide attributes used in [FirstOrCreate] or [FirstOrInit]
+//
+// Assign adds attributes even if the record is found. If using FirstOrCreate, this means that
+// records will be updated even if they are found.
+//
+//	// assign an email regardless of if the record is not found
+//	db.Where(User{Name: "non_existing"}).Assign(User{Email: "fake@fake.org"}).FirstOrInit(&user)
+//	// user -> User{Name: "non_existing", Email: "fake@fake.org"}
+//
+//	// assign email regardless of if record is found
+//	db.Where(User{Name: "jinzhu"}).Assign(User{Email: "fake@fake.org"}).FirstOrInit(&user)
+//	// user -> User{Name: "jinzhu", Age: 20, Email: "fake@fake.org"}
+//
+// [FirstOrCreate]: https://gorm.io/docs/advanced_query.html#FirstOrCreate
+// [FirstOrInit]: https://gorm.io/docs/advanced_query.html#FirstOrInit
 func (db *DB) Assign(attrs ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.assigns = attrs
 	return
 }
 
+// Unscoped disables the global scope of soft deletion in a query.
+// By default, GORM uses soft deletion, marking records as "deleted"
+// by setting a timestamp on a specific field (e.g., `deleted_at`).
+// Unscoped allows queries to include records marked as deleted,
+// overriding the soft deletion behavior.
+// Example:
+//
+//	var users []User
+//	db.Unscoped().Find(&users)
+//	// Retrieves all users, including deleted ones.
 func (db *DB) Unscoped() (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Unscoped = true

clause/benchmarks_test.go

@@ -29,10 +29,12 @@ func BenchmarkSelect(b *testing.B) {
 func BenchmarkComplexSelect(b *testing.B) {
 	user, _ := schema.Parse(&tests.User{}, &sync.Map{}, db.NamingStrategy)
 
+	limit10 := 10
 	for i := 0; i < b.N; i++ {
 		stmt := gorm.Statement{DB: db, Table: user.Table, Schema: user, Clauses: map[string]clause.Clause{}}
 		clauses := []clause.Interface{
-			clause.Select{}, clause.From{},
+			clause.Select{},
+			clause.From{},
 			clause.Where{Exprs: []clause.Expression{
 				clause.Eq{Column: clause.PrimaryColumn, Value: "1"},
 				clause.Gt{Column: "age", Value: 18},
@@ -42,7 +44,7 @@ func BenchmarkComplexSelect(b *testing.B) {
 				clause.Or(clause.Gt{Column: "score", Value: 100}, clause.Like{Column: "name", Value: "%linus%"}),
 			}},
 			clause.GroupBy{Columns: []clause.Column{{Name: "role"}}, Having: []clause.Expression{clause.Eq{"role", "admin"}}},
-			clause.Limit{Limit: 10, Offset: 20},
+			clause.Limit{Limit: &limit10, Offset: 20},
 			clause.OrderBy{Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}}},
 		}
 

clause/clause.go

@@ -20,6 +20,7 @@ type Builder interface {
 	Writer
 	WriteQuoted(field interface{})
 	AddVar(Writer, ...interface{})
+	AddError(error) error
 }
 
 // Clause

clause/expression.go

@@ -67,6 +67,12 @@ func (expr Expr) Build(builder Builder) {
 			builder.WriteByte(v)
 		}
 	}
+
+	if idx < len(expr.Vars) {
+		for _, v := range expr.Vars[idx:] {
+			builder.AddVar(builder, sql.NamedArg{Value: v})
+		}
+	}
 }
 
 // NamedExpr raw expression for named expr
@@ -120,8 +126,8 @@ func (expr NamedExpr) Build(builder Builder) {
 	for _, v := range []byte(expr.SQL) {
 		if v == '@' && !inName {
 			inName = true
-			name = []byte{}
-		} else if v == ' ' || v == ',' || v == ')' || v == '"' || v == '\'' || v == '`' || v == '\n' {
+			name = name[:0]
+		} else if v == ' ' || v == ',' || v == ')' || v == '"' || v == '\'' || v == '`' || v == '\r' || v == '\n' || v == ';' {
 			if inName {
 				if nv, ok := namedMap[string(name)]; ok {
 					builder.AddVar(builder, nv)
@@ -173,7 +179,12 @@ func (expr NamedExpr) Build(builder Builder) {
 	}
 
 	if inName {
-		builder.AddVar(builder, namedMap[string(name)])
+		if nv, ok := namedMap[string(name)]; ok {
+			builder.AddVar(builder, nv)
+		} else {
+			builder.WriteByte('@')
+			builder.WriteString(string(name))
+		}
 	}
 }
 
@@ -205,11 +216,12 @@ func (in IN) Build(builder Builder) {
 }
 
 func (in IN) NegationBuild(builder Builder) {
+	builder.WriteQuoted(in.Column)
 	switch len(in.Values) {
 	case 0:
+		builder.WriteString(" IS NOT NULL")
 	case 1:
 		if _, ok := in.Values[0].([]interface{}); !ok {
-			builder.WriteQuoted(in.Column)
 			builder.WriteString(" <> ")
 			builder.AddVar(builder, in.Values[0])
 			break
@@ -217,7 +229,6 @@ func (in IN) NegationBuild(builder Builder) {
 
 		fallthrough
 	default:
-		builder.WriteQuoted(in.Column)
 		builder.WriteString(" NOT IN (")
 		builder.AddVar(builder, in.Values...)
 		builder.WriteByte(')')
@@ -233,11 +244,28 @@ type Eq struct {
 func (eq Eq) Build(builder Builder) {
 	builder.WriteQuoted(eq.Column)
 
-	if eqNil(eq.Value) {
-		builder.WriteString(" IS NULL")
-	} else {
-		builder.WriteString(" = ")
-		builder.AddVar(builder, eq.Value)
+	switch eq.Value.(type) {
+	case []string, []int, []int32, []int64, []uint, []uint32, []uint64, []interface{}:
+		rv := reflect.ValueOf(eq.Value)
+		if rv.Len() == 0 {
+			builder.WriteString(" IN (NULL)")
+		} else {
+			builder.WriteString(" IN (")
+			for i := 0; i < rv.Len(); i++ {
+				if i > 0 {
+					builder.WriteByte(',')
+				}
+				builder.AddVar(builder, rv.Index(i).Interface())
+			}
+			builder.WriteByte(')')
+		}
+	default:
+		if eqNil(eq.Value) {
+			builder.WriteString(" IS NULL")
+		} else {
+			builder.WriteString(" = ")
+			builder.AddVar(builder, eq.Value)
+		}
 	}
 }
 
@@ -251,11 +279,24 @@ type Neq Eq
 func (neq Neq) Build(builder Builder) {
 	builder.WriteQuoted(neq.Column)
 
-	if eqNil(neq.Value) {
-		builder.WriteString(" IS NOT NULL")
-	} else {
-		builder.WriteString(" <> ")
-		builder.AddVar(builder, neq.Value)
+	switch neq.Value.(type) {
+	case []string, []int, []int32, []int64, []uint, []uint32, []uint64, []interface{}:
+		builder.WriteString(" NOT IN (")
+		rv := reflect.ValueOf(neq.Value)
+		for i := 0; i < rv.Len(); i++ {
+			if i > 0 {
+				builder.WriteByte(',')
+			}
+			builder.AddVar(builder, rv.Index(i).Interface())
+		}
+		builder.WriteByte(')')
+	default:
+		if eqNil(neq.Value) {
+			builder.WriteString(" IS NOT NULL")
+		} else {
+			builder.WriteString(" <> ")
+			builder.AddVar(builder, neq.Value)
+		}
 	}
 }
 
@@ -331,7 +372,7 @@ func (like Like) NegationBuild(builder Builder) {
 }
 
 func eqNil(value interface{}) bool {
-	if valuer, ok := value.(driver.Valuer); ok {
+	if valuer, ok := value.(driver.Valuer); ok && !eqNilReflect(valuer) {
 		value, _ = valuer.Value()
 	}
 

clause/expression_test.go

@@ -60,6 +60,11 @@ func TestNamedExpr(t *testing.T) {
 		Vars:         []interface{}{sql.Named("name", "jinzhu")},
 		Result:       "name1 = ? AND name2 = ?",
 		ExpectedVars: []interface{}{"jinzhu", "jinzhu"},
+	}, {
+		SQL:          "name1 = @name AND name2 = @@name",
+		Vars:         []interface{}{map[string]interface{}{"name": "jinzhu"}},
+		Result:       "name1 = ? AND name2 = @@name",
+		ExpectedVars: []interface{}{"jinzhu"},
 	}, {
 		SQL:          "name1 = @name1 AND name2 = @name2 AND name3 = @name1",
 		Vars:         []interface{}{sql.Named("name1", "jinzhu"), sql.Named("name2", "jinzhu2")},
@@ -73,17 +78,60 @@ func TestNamedExpr(t *testing.T) {
 	}, {
 		SQL:          "@@test AND name1 = @name1 AND name2 = @name2 AND name3 = @name1 @notexist",
 		Vars:         []interface{}{sql.Named("name1", "jinzhu"), sql.Named("name2", "jinzhu2")},
-		Result:       "@@test AND name1 = ? AND name2 = ? AND name3 = ? ?",
-		ExpectedVars: []interface{}{"jinzhu", "jinzhu2", "jinzhu", nil},
+		Result:       "@@test AND name1 = ? AND name2 = ? AND name3 = ? @notexist",
+		ExpectedVars: []interface{}{"jinzhu", "jinzhu2", "jinzhu"},
 	}, {
-		SQL:          "@@test AND name1 = @Name1 AND name2 = @Name2 AND name3 = @Name1 @Notexist",
+		SQL:          "@@test AND name1 = @Name1 AND name2 = @Name2 AND name3 = @Name1 @notexist",
 		Vars:         []interface{}{NamedArgument{Name1: "jinzhu", Base: Base{Name2: "jinzhu2"}}},
-		Result:       "@@test AND name1 = ? AND name2 = ? AND name3 = ? ?",
-		ExpectedVars: []interface{}{"jinzhu", "jinzhu2", "jinzhu", nil},
+		Result:       "@@test AND name1 = ? AND name2 = ? AND name3 = ? @notexist",
+		ExpectedVars: []interface{}{"jinzhu", "jinzhu2", "jinzhu"},
 	}, {
 		SQL:    "create table ? (? ?, ? ?)",
 		Vars:   []interface{}{},
 		Result: "create table ? (? ?, ? ?)",
+	}, {
+		SQL:          "name1 = @name AND name2 = @name;",
+		Vars:         []interface{}{sql.Named("name", "jinzhu")},
+		Result:       "name1 = ? AND name2 = ?;",
+		ExpectedVars: []interface{}{"jinzhu", "jinzhu"},
+	}, {
+		SQL:          "name1 = @name1\r\n AND name2 = @name2",
+		Vars:         []interface{}{map[string]interface{}{"name1": "jinzhu", "name2": "jinzhu"}},
+		Result:       "name1 = ?\r\n AND name2 = ?",
+		ExpectedVars: []interface{}{"jinzhu", "jinzhu"},
+	}, {
+		SQL:          "name1 = @name1\r AND name2 = @name2",
+		Vars:         []interface{}{map[string]interface{}{"name1": "jinzhu", "name2": "jinzhu"}},
+		Result:       "name1 = ?\r AND name2 = ?",
+		ExpectedVars: []interface{}{"jinzhu", "jinzhu"},
+	}, {
+		SQL:    "?",
+		Vars:   []interface{}{clause.Column{Table: "table", Name: "col"}},
+		Result: "`table`.`col`",
+	}, {
+		SQL:    "?",
+		Vars:   []interface{}{clause.Column{Table: "table", Name: "col", Raw: true}},
+		Result: "table.col",
+	}, {
+		SQL:    "?",
+		Vars:   []interface{}{clause.Column{Table: "table", Name: clause.PrimaryKey, Raw: true}},
+		Result: "table.id",
+	}, {
+		SQL:    "?",
+		Vars:   []interface{}{clause.Column{Table: "table", Name: "col", Alias: "alias"}},
+		Result: "`table`.`col` AS `alias`",
+	}, {
+		SQL:    "?",
+		Vars:   []interface{}{clause.Column{Table: "table", Name: "col", Alias: "alias", Raw: true}},
+		Result: "table.col AS alias",
+	}, {
+		SQL:    "?",
+		Vars:   []interface{}{clause.Table{Name: "table", Alias: "alias"}},
+		Result: "`table` `alias`",
+	}, {
+		SQL:    "?",
+		Vars:   []interface{}{clause.Table{Name: "table", Alias: "alias", Raw: true}},
+		Result: "table alias",
 	}}
 
 	for idx, result := range results {
@@ -105,13 +153,15 @@ func TestNamedExpr(t *testing.T) {
 func TestExpression(t *testing.T) {
 	column := "column-name"
 	results := []struct {
-		Expressions []clause.Expression
-		Result      string
+		Expressions  []clause.Expression
+		ExpectedVars []interface{}
+		Result       string
 	}{{
 		Expressions: []clause.Expression{
 			clause.Eq{Column: column, Value: "column-value"},
 		},
-		Result: "`column-name` = ?",
+		ExpectedVars: []interface{}{"column-value"},
+		Result:       "`column-name` = ?",
 	}, {
 		Expressions: []clause.Expression{
 			clause.Eq{Column: column, Value: nil},
@@ -126,7 +176,8 @@ func TestExpression(t *testing.T) {
 		Expressions: []clause.Expression{
 			clause.Neq{Column: column, Value: "column-value"},
 		},
-		Result: "`column-name` <> ?",
+		ExpectedVars: []interface{}{"column-value"},
+		Result:       "`column-name` <> ?",
 	}, {
 		Expressions: []clause.Expression{
 			clause.Neq{Column: column, Value: nil},
@@ -136,6 +187,35 @@ func TestExpression(t *testing.T) {
 			clause.Neq{Column: column, Value: (interface{})(nil)},
 		},
 		Result: "`column-name` IS NOT NULL",
+	}, {
+		Expressions: []clause.Expression{
+			clause.Eq{Column: column, Value: []string{"a", "b"}},
+		},
+		ExpectedVars: []interface{}{"a", "b"},
+		Result:       "`column-name` IN (?,?)",
+	}, {
+		Expressions: []clause.Expression{
+			clause.Neq{Column: column, Value: []string{"a", "b"}},
+		},
+		ExpectedVars: []interface{}{"a", "b"},
+		Result:       "`column-name` NOT IN (?,?)",
+	}, {
+		Expressions: []clause.Expression{
+			clause.Eq{Column: column, Value: []string{}},
+		},
+		Result: "`column-name` IN (NULL)",
+	}, {
+		Expressions: []clause.Expression{
+			clause.Eq{Column: clause.Expr{SQL: "SUM(?)", Vars: []interface{}{clause.Column{Name: "id"}}}, Value: 100},
+		},
+		ExpectedVars: []interface{}{100},
+		Result:       "SUM(`id`) = ?",
+	}, {
+		Expressions: []clause.Expression{
+			clause.Gte{Column: clause.Expr{SQL: "SUM(?)", Vars: []interface{}{clause.Column{Table: "users", Name: "id"}}}, Value: 100},
+		},
+		ExpectedVars: []interface{}{100},
+		Result:       "SUM(`users`.`id`) >= ?",
 	}}
 
 	for idx, result := range results {
@@ -147,6 +227,10 @@ func TestExpression(t *testing.T) {
 				if stmt.SQL.String() != result.Result {
 					t.Errorf("generated SQL is not equal, expects %v, but got %v", result.Result, stmt.SQL.String())
 				}
+
+				if !reflect.DeepEqual(result.ExpectedVars, stmt.Vars) {
+					t.Errorf("generated vars is not equal, expects %v, but got %v", result.ExpectedVars, stmt.Vars)
+				}
 			})
 		}
 	}

clause/group_by.go

@@ -39,4 +39,10 @@ func (groupBy GroupBy) MergeClause(clause *Clause) {
 		groupBy.Having = append(copiedHaving, groupBy.Having...)
 	}
 	clause.Expression = groupBy
+
+	if len(groupBy.Columns) == 0 {
+		clause.Name = ""
+	} else {
+		clause.Name = groupBy.Name()
+	}
 }

clause/group_by_test.go

@@ -18,7 +18,8 @@ func TestGroupBy(t *testing.T) {
 				Columns: []clause.Column{{Name: "role"}},
 				Having:  []clause.Expression{clause.Eq{"role", "admin"}},
 			}},
-			"SELECT * FROM `users` GROUP BY `role` HAVING `role` = ?", []interface{}{"admin"},
+			"SELECT * FROM `users` GROUP BY `role` HAVING `role` = ?",
+			[]interface{}{"admin"},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.GroupBy{
@@ -28,7 +29,8 @@ func TestGroupBy(t *testing.T) {
 				Columns: []clause.Column{{Name: "gender"}},
 				Having:  []clause.Expression{clause.Neq{"gender", "U"}},
 			}},
-			"SELECT * FROM `users` GROUP BY `role`,`gender` HAVING `role` = ? AND `gender` <> ?", []interface{}{"admin", "U"},
+			"SELECT * FROM `users` GROUP BY `role`,`gender` HAVING `role` = ? AND `gender` <> ?",
+			[]interface{}{"admin", "U"},
 		},
 	}
 

clause/joins.go

@@ -1,5 +1,7 @@
 package clause
 
+import "gorm.io/gorm/utils"
+
 type JoinType string
 
 const (
@@ -9,7 +11,31 @@ const (
 	RightJoin JoinType = "RIGHT"
 )
 
-// Join join clause for from
+type JoinTarget struct {
+	Type        JoinType
+	Association string
+	Subquery    Expression
+	Table       string
+}
+
+func Has(name string) JoinTarget {
+	return JoinTarget{Type: InnerJoin, Association: name}
+}
+
+func (jt JoinType) Association(name string) JoinTarget {
+	return JoinTarget{Type: jt, Association: name}
+}
+
+func (jt JoinType) AssociationFrom(name string, subquery Expression) JoinTarget {
+	return JoinTarget{Type: jt, Association: name, Subquery: subquery}
+}
+
+func (jt JoinTarget) As(name string) JoinTarget {
+	jt.Table = name
+	return jt
+}
+
+// Join clause for from
 type Join struct {
 	Type       JoinType
 	Table      Table
@@ -18,6 +44,12 @@ type Join struct {
 	Expression Expression
 }
 
+func JoinTable(names ...string) Table {
+	return Table{
+		Name: utils.JoinNestedRelationNames(names),
+	}
+}
+
 func (join Join) Build(builder Builder) {
 	if join.Expression != nil {
 		join.Expression.Build(builder)

clause/joins_test.go

@@ -0,0 +1,101 @@
+package clause_test
+
+import (
+	"sync"
+	"testing"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils/tests"
+)
+
+func TestJoin(t *testing.T) {
+	results := []struct {
+		name string
+		join clause.Join
+		sql  string
+	}{
+		{
+			name: "LEFT JOIN",
+			join: clause.Join{
+				Type:  clause.LeftJoin,
+				Table: clause.Table{Name: "user"},
+				ON: clause.Where{
+					Exprs: []clause.Expression{clause.Eq{clause.Column{Table: "user_info", Name: "user_id"}, clause.PrimaryColumn}},
+				},
+			},
+			sql: "LEFT JOIN `user` ON `user_info`.`user_id` = `users`.`id`",
+		},
+		{
+			name: "RIGHT JOIN",
+			join: clause.Join{
+				Type:  clause.RightJoin,
+				Table: clause.Table{Name: "user"},
+				ON: clause.Where{
+					Exprs: []clause.Expression{clause.Eq{clause.Column{Table: "user_info", Name: "user_id"}, clause.PrimaryColumn}},
+				},
+			},
+			sql: "RIGHT JOIN `user` ON `user_info`.`user_id` = `users`.`id`",
+		},
+		{
+			name: "INNER JOIN",
+			join: clause.Join{
+				Type:  clause.InnerJoin,
+				Table: clause.Table{Name: "user"},
+				ON: clause.Where{
+					Exprs: []clause.Expression{clause.Eq{clause.Column{Table: "user_info", Name: "user_id"}, clause.PrimaryColumn}},
+				},
+			},
+			sql: "INNER JOIN `user` ON `user_info`.`user_id` = `users`.`id`",
+		},
+		{
+			name: "CROSS JOIN",
+			join: clause.Join{
+				Type:  clause.CrossJoin,
+				Table: clause.Table{Name: "user"},
+				ON: clause.Where{
+					Exprs: []clause.Expression{clause.Eq{clause.Column{Table: "user_info", Name: "user_id"}, clause.PrimaryColumn}},
+				},
+			},
+			sql: "CROSS JOIN `user` ON `user_info`.`user_id` = `users`.`id`",
+		},
+		{
+			name: "USING",
+			join: clause.Join{
+				Type:  clause.InnerJoin,
+				Table: clause.Table{Name: "user"},
+				Using: []string{"id"},
+			},
+			sql: "INNER JOIN `user` USING (`id`)",
+		},
+		{
+			name: "Expression",
+			join: clause.Join{
+				// Invalid
+				Type:  clause.LeftJoin,
+				Table: clause.Table{Name: "user"},
+				ON: clause.Where{
+					Exprs: []clause.Expression{clause.Eq{clause.Column{Table: "user_info", Name: "user_id"}, clause.PrimaryColumn}},
+				},
+				// Valid
+				Expression: clause.Join{
+					Type:  clause.InnerJoin,
+					Table: clause.Table{Name: "user"},
+					Using: []string{"id"},
+				},
+			},
+			sql: "INNER JOIN `user` USING (`id`)",
+		},
+	}
+	for _, result := range results {
+		t.Run(result.name, func(t *testing.T) {
+			user, _ := schema.Parse(&tests.User{}, &sync.Map{}, db.NamingStrategy)
+			stmt := &gorm.Statement{DB: db, Table: user.Table, Schema: user, Clauses: map[string]clause.Clause{}}
+			result.join.Build(stmt)
+			if result.sql != stmt.SQL.String() {
+				t.Errorf("want: %s, got: %s", result.sql, stmt.SQL.String())
+			}
+		})
+	}
+}

clause/limit.go

@@ -1,10 +1,8 @@
 package clause
 
-import "strconv"
-
 // Limit limit clause
 type Limit struct {
-	Limit  int
+	Limit  *int
 	Offset int
 }
 
@@ -15,16 +13,16 @@ func (limit Limit) Name() string {
 
 // Build build where clause
 func (limit Limit) Build(builder Builder) {
-	if limit.Limit > 0 {
+	if limit.Limit != nil && *limit.Limit >= 0 {
 		builder.WriteString("LIMIT ")
-		builder.WriteString(strconv.Itoa(limit.Limit))
+		builder.AddVar(builder, *limit.Limit)
 	}
 	if limit.Offset > 0 {
-		if limit.Limit > 0 {
-			builder.WriteString(" ")
+		if limit.Limit != nil && *limit.Limit >= 0 {
+			builder.WriteByte(' ')
 		}
 		builder.WriteString("OFFSET ")
-		builder.WriteString(strconv.Itoa(limit.Offset))
+		builder.AddVar(builder, limit.Offset)
 	}
 }
 
@@ -33,7 +31,7 @@ func (limit Limit) MergeClause(clause *Clause) {
 	clause.Name = ""
 
 	if v, ok := clause.Expression.(Limit); ok {
-		if limit.Limit == 0 && v.Limit != 0 {
+		if (limit.Limit == nil || *limit.Limit == 0) && v.Limit != nil {
 			limit.Limit = v.Limit
 		}
 

clause/limit_test.go

@@ -8,6 +8,10 @@ import (
 )
 
 func TestLimit(t *testing.T) {
+	limit0 := 0
+	limit10 := 10
+	limit50 := 50
+	limitNeg10 := -10
 	results := []struct {
 		Clauses []clause.Interface
 		Result  string
@@ -15,38 +19,56 @@ func TestLimit(t *testing.T) {
 	}{
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{
-				Limit:  10,
+				Limit:  &limit10,
 				Offset: 20,
 			}},
-			"SELECT * FROM `users` LIMIT 10 OFFSET 20", nil,
+			"SELECT * FROM `users` LIMIT ? OFFSET ?",
+			[]interface{}{limit10, 20},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit0}},
+			"SELECT * FROM `users` LIMIT ?",
+			[]interface{}{limit0},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit0}, clause.Limit{Offset: 0}},
+			"SELECT * FROM `users` LIMIT ?",
+			[]interface{}{limit0},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Offset: 20}},
-			"SELECT * FROM `users` OFFSET 20", nil,
+			"SELECT * FROM `users` OFFSET ?",
+			[]interface{}{20},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Offset: 20}, clause.Limit{Offset: 30}},
-			"SELECT * FROM `users` OFFSET 30", nil,
+			"SELECT * FROM `users` OFFSET ?",
+			[]interface{}{30},
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Offset: 20}, clause.Limit{Limit: 10}},
-			"SELECT * FROM `users` LIMIT 10 OFFSET 20", nil,
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Offset: 20}, clause.Limit{Limit: &limit10}},
+			"SELECT * FROM `users` LIMIT ? OFFSET ?",
+			[]interface{}{limit10, 20},
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: 10, Offset: 20}, clause.Limit{Offset: 30}},
-			"SELECT * FROM `users` LIMIT 10 OFFSET 30", nil,
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit10, Offset: 20}, clause.Limit{Offset: 30}},
+			"SELECT * FROM `users` LIMIT ? OFFSET ?",
+			[]interface{}{limit10, 30},
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: 10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Offset: -10}},
-			"SELECT * FROM `users` LIMIT 10", nil,
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Offset: -10}},
+			"SELECT * FROM `users` LIMIT ?",
+			[]interface{}{limit10},
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: 10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Limit: -10}},
-			"SELECT * FROM `users` OFFSET 30", nil,
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Limit: &limitNeg10}},
+			"SELECT * FROM `users` OFFSET ?",
+			[]interface{}{30},
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: 10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Limit: 50}},
-			"SELECT * FROM `users` LIMIT 50 OFFSET 30", nil,
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Limit: &limit50}},
+			"SELECT * FROM `users` LIMIT ? OFFSET ?",
+			[]interface{}{limit50, 30},
 		},
 	}
 

clause/locking.go

@@ -1,5 +1,12 @@
 package clause
 
+const (
+	LockingStrengthUpdate    = "UPDATE"
+	LockingStrengthShare     = "SHARE"
+	LockingOptionsSkipLocked = "SKIP LOCKED"
+	LockingOptionsNoWait     = "NOWAIT"
+)
+
 type Locking struct {
 	Strength string
 	Table    Table

clause/locking_test.go

@@ -14,17 +14,21 @@ func TestLocking(t *testing.T) {
 		Vars    []interface{}
 	}{
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: "UPDATE"}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate}},
 			"SELECT * FROM `users` FOR UPDATE", nil,
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: "SHARE", Table: clause.Table{Name: clause.CurrentTable}}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthShare, Table: clause.Table{Name: clause.CurrentTable}}},
 			"SELECT * FROM `users` FOR SHARE OF `users`", nil,
 		},
 		{
-			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: "UPDATE"}, clause.Locking{Strength: "UPDATE", Options: "NOWAIT"}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate, Options: clause.LockingOptionsNoWait}},
 			"SELECT * FROM `users` FOR UPDATE NOWAIT", nil,
 		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Locking{Strength: clause.LockingStrengthUpdate, Options: clause.LockingOptionsSkipLocked}},
+			"SELECT * FROM `users` FOR UPDATE SKIP LOCKED", nil,
+		},
 	}
 
 	for idx, result := range results {

clause/on_conflict.go

@@ -3,6 +3,7 @@ package clause
 type OnConflict struct {
 	Columns      []Column
 	Where        Where
+	TargetWhere  Where
 	OnConstraint string
 	DoNothing    bool
 	DoUpdates    Set
@@ -15,21 +16,27 @@ func (OnConflict) Name() string {
 
 // Build build onConflict clause
 func (onConflict OnConflict) Build(builder Builder) {
-	if len(onConflict.Columns) > 0 {
-		builder.WriteByte('(')
-		for idx, column := range onConflict.Columns {
-			if idx > 0 {
-				builder.WriteByte(',')
-			}
-			builder.WriteQuoted(column)
-		}
-		builder.WriteString(`) `)
-	}
-
 	if onConflict.OnConstraint != "" {
 		builder.WriteString("ON CONSTRAINT ")
 		builder.WriteString(onConflict.OnConstraint)
 		builder.WriteByte(' ')
+	} else {
+		if len(onConflict.Columns) > 0 {
+			builder.WriteByte('(')
+			for idx, column := range onConflict.Columns {
+				if idx > 0 {
+					builder.WriteByte(',')
+				}
+				builder.WriteQuoted(column)
+			}
+			builder.WriteString(`) `)
+		}
+
+		if len(onConflict.TargetWhere.Exprs) > 0 {
+			builder.WriteString(" WHERE ")
+			onConflict.TargetWhere.Build(builder)
+			builder.WriteByte(' ')
+		}
 	}
 
 	if onConflict.DoNothing {
@@ -40,7 +47,7 @@ func (onConflict OnConflict) Build(builder Builder) {
 	}
 
 	if len(onConflict.Where.Exprs) > 0 {
-		builder.WriteString("WHERE ")
+		builder.WriteString(" WHERE ")
 		onConflict.Where.Build(builder)
 		builder.WriteByte(' ')
 	}

clause/order_by_test.go

@@ -45,7 +45,8 @@ func TestOrderBy(t *testing.T) {
 					Expression: clause.Expr{SQL: "FIELD(id, ?)", Vars: []interface{}{[]int{1, 2, 3}}, WithoutParentheses: true},
 				},
 			},
-			"SELECT * FROM `users` ORDER BY FIELD(id, ?,?,?)", []interface{}{1, 2, 3},
+			"SELECT * FROM `users` ORDER BY FIELD(id, ?,?,?)",
+			[]interface{}{1, 2, 3},
 		},
 	}
 

clause/returning.go

@@ -11,20 +11,27 @@ func (returning Returning) Name() string {
 
 // Build build where clause
 func (returning Returning) Build(builder Builder) {
-	for idx, column := range returning.Columns {
-		if idx > 0 {
-			builder.WriteByte(',')
-		}
+	if len(returning.Columns) > 0 {
+		for idx, column := range returning.Columns {
+			if idx > 0 {
+				builder.WriteByte(',')
+			}
 
-		builder.WriteQuoted(column)
+			builder.WriteQuoted(column)
+		}
+	} else {
+		builder.WriteByte('*')
 	}
 }
 
 // MergeClause merge order by clauses
 func (returning Returning) MergeClause(clause *Clause) {
-	if v, ok := clause.Expression.(Returning); ok {
-		returning.Columns = append(v.Columns, returning.Columns...)
+	if v, ok := clause.Expression.(Returning); ok && len(returning.Columns) > 0 {
+		if v.Columns != nil {
+			returning.Columns = append(v.Columns, returning.Columns...)
+		} else {
+			returning.Columns = nil
+		}
 	}
-
 	clause.Expression = returning
 }

clause/returning_test.go

@@ -26,6 +26,22 @@ func TestReturning(t *testing.T) {
 			}},
 			"SELECT * FROM `users` RETURNING `users`.`id`,`name`,`age`", nil,
 		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Returning{
+				[]clause.Column{clause.PrimaryColumn},
+			}, clause.Returning{}, clause.Returning{
+				[]clause.Column{{Name: "name"}, {Name: "age"}},
+			}},
+			"SELECT * FROM `users` RETURNING *", nil,
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Returning{
+				[]clause.Column{clause.PrimaryColumn},
+			}, clause.Returning{
+				[]clause.Column{{Name: "name"}, {Name: "age"}},
+			}, clause.Returning{}},
+			"SELECT * FROM `users` RETURNING *", nil,
+		},
 	}
 
 	for idx, result := range results {

clause/select.go

@@ -43,3 +43,17 @@ func (s Select) MergeClause(clause *Clause) {
 		clause.Expression = s
 	}
 }
+
+// CommaExpression represents a group of expressions separated by commas.
+type CommaExpression struct {
+	Exprs []Expression
+}
+
+func (comma CommaExpression) Build(builder Builder) {
+	for idx, expr := range comma.Exprs {
+		if idx > 0 {
+			_, _ = builder.WriteString(", ")
+		}
+		expr.Build(builder)
+	}
+}

clause/select_test.go

@@ -31,6 +31,37 @@ func TestSelect(t *testing.T) {
 			}, clause.From{}},
 			"SELECT `name` FROM `users`", nil,
 		},
+		{
+			[]clause.Interface{clause.Select{
+				Expression: clause.CommaExpression{
+					Exprs: []clause.Expression{
+						clause.NamedExpr{"?", []interface{}{clause.Column{Name: "id"}}},
+						clause.NamedExpr{"?", []interface{}{clause.Column{Name: "name"}}},
+						clause.NamedExpr{"LENGTH(?)", []interface{}{clause.Column{Name: "mobile"}}},
+					},
+				},
+			}, clause.From{}},
+			"SELECT `id`, `name`, LENGTH(`mobile`) FROM `users`", nil,
+		},
+		{
+			[]clause.Interface{clause.Select{
+				Expression: clause.CommaExpression{
+					Exprs: []clause.Expression{
+						clause.Expr{
+							SQL: "? as name",
+							Vars: []interface{}{
+								clause.Eq{
+									Column: clause.Column{Name: "age"},
+									Value:  18,
+								},
+							},
+						},
+					},
+				},
+			}, clause.From{}},
+			"SELECT `age` = ? as name FROM `users`",
+			[]interface{}{18},
+		},
 	}
 
 	for idx, result := range results {

clause/set.go

@@ -24,9 +24,9 @@ func (set Set) Build(builder Builder) {
 			builder.AddVar(builder, assignment.Value)
 		}
 	} else {
-		builder.WriteQuoted(PrimaryColumn)
+		builder.WriteQuoted(Column{Name: PrimaryKey})
 		builder.WriteByte('=')
-		builder.WriteQuoted(PrimaryColumn)
+		builder.WriteQuoted(Column{Name: PrimaryKey})
 	}
 }
 

clause/set_test.go

@@ -20,7 +20,8 @@ func TestSet(t *testing.T) {
 				clause.Update{},
 				clause.Set([]clause.Assignment{{clause.PrimaryColumn, 1}}),
 			},
-			"UPDATE `users` SET `users`.`id`=?", []interface{}{1},
+			"UPDATE `users` SET `users`.`id`=?",
+			[]interface{}{1},
 		},
 		{
 			[]clause.Interface{
@@ -28,7 +29,8 @@ func TestSet(t *testing.T) {
 				clause.Set([]clause.Assignment{{clause.PrimaryColumn, 1}}),
 				clause.Set([]clause.Assignment{{clause.Column{Name: "name"}, "jinzhu"}}),
 			},
-			"UPDATE `users` SET `name`=?", []interface{}{"jinzhu"},
+			"UPDATE `users` SET `name`=?",
+			[]interface{}{"jinzhu"},
 		},
 	}
 

clause/values_test.go

@@ -21,7 +21,8 @@ func TestValues(t *testing.T) {
 					Values:  [][]interface{}{{"jinzhu", 18}, {"josh", 1}},
 				},
 			},
-			"INSERT INTO `users` (`name`,`age`) VALUES (?,?),(?,?)", []interface{}{"jinzhu", 18, "josh", 1},
+			"INSERT INTO `users` (`name`,`age`) VALUES (?,?),(?,?)",
+			[]interface{}{"jinzhu", 18, "josh", 1},
 		},
 	}
 

clause/where.go

@@ -4,6 +4,11 @@ import (
 	"strings"
 )
 
+const (
+	AndWithSpace = " AND "
+	OrWithSpace  = " OR "
+)
+
 // Where where clause
 type Where struct {
 	Exprs []Expression
@@ -16,6 +21,12 @@ func (where Where) Name() string {
 
 // Build build where clause
 func (where Where) Build(builder Builder) {
+	if len(where.Exprs) == 1 {
+		if andCondition, ok := where.Exprs[0].(AndConditions); ok {
+			where.Exprs = andCondition.Exprs
+		}
+	}
+
 	// Switch position if the first query expression is a single Or condition
 	for idx, expr := range where.Exprs {
 		if v, ok := expr.(OrConditions); !ok || len(v.Exprs) > 1 {
@@ -26,7 +37,7 @@ func (where Where) Build(builder Builder) {
 		}
 	}
 
-	buildExprs(where.Exprs, builder, " AND ")
+	buildExprs(where.Exprs, builder, AndWithSpace)
 }
 
 func buildExprs(exprs []Expression, builder Builder, joinCond string) {
@@ -35,7 +46,7 @@ func buildExprs(exprs []Expression, builder Builder, joinCond string) {
 	for idx, expr := range exprs {
 		if idx > 0 {
 			if v, ok := expr.(OrConditions); ok && len(v.Exprs) == 1 {
-				builder.WriteString(" OR ")
+				builder.WriteString(OrWithSpace)
 			} else {
 				builder.WriteString(joinCond)
 			}
@@ -46,27 +57,30 @@ func buildExprs(exprs []Expression, builder Builder, joinCond string) {
 			case OrConditions:
 				if len(v.Exprs) == 1 {
 					if e, ok := v.Exprs[0].(Expr); ok {
-						sql := strings.ToLower(e.SQL)
-						wrapInParentheses = strings.Contains(sql, "and") || strings.Contains(sql, "or")
+						sql := strings.ToUpper(e.SQL)
+						wrapInParentheses = strings.Contains(sql, AndWithSpace) || strings.Contains(sql, OrWithSpace)
 					}
 				}
 			case AndConditions:
 				if len(v.Exprs) == 1 {
 					if e, ok := v.Exprs[0].(Expr); ok {
-						sql := strings.ToLower(e.SQL)
-						wrapInParentheses = strings.Contains(sql, "and") || strings.Contains(sql, "or")
+						sql := strings.ToUpper(e.SQL)
+						wrapInParentheses = strings.Contains(sql, AndWithSpace) || strings.Contains(sql, OrWithSpace)
 					}
 				}
 			case Expr:
-				sql := strings.ToLower(v.SQL)
-				wrapInParentheses = strings.Contains(sql, "and") || strings.Contains(sql, "or")
+				sql := strings.ToUpper(v.SQL)
+				wrapInParentheses = strings.Contains(sql, AndWithSpace) || strings.Contains(sql, OrWithSpace)
+			case NamedExpr:
+				sql := strings.ToUpper(v.SQL)
+				wrapInParentheses = strings.Contains(sql, AndWithSpace) || strings.Contains(sql, OrWithSpace)
 			}
 		}
 
 		if wrapInParentheses {
-			builder.WriteString(`(`)
+			builder.WriteByte('(')
 			expr.Build(builder)
-			builder.WriteString(`)`)
+			builder.WriteByte(')')
 			wrapInParentheses = false
 		} else {
 			expr.Build(builder)
@@ -89,9 +103,14 @@ func (where Where) MergeClause(clause *Clause) {
 func And(exprs ...Expression) Expression {
 	if len(exprs) == 0 {
 		return nil
-	} else if len(exprs) == 1 {
-		return exprs[0]
 	}
+
+	if len(exprs) == 1 {
+		if _, ok := exprs[0].(OrConditions); !ok {
+			return exprs[0]
+		}
+	}
+
 	return AndConditions{Exprs: exprs}
 }
 
@@ -102,10 +121,10 @@ type AndConditions struct {
 func (and AndConditions) Build(builder Builder) {
 	if len(and.Exprs) > 1 {
 		builder.WriteByte('(')
-		buildExprs(and.Exprs, builder, " AND ")
+		buildExprs(and.Exprs, builder, AndWithSpace)
 		builder.WriteByte(')')
 	} else {
-		buildExprs(and.Exprs, builder, " AND ")
+		buildExprs(and.Exprs, builder, AndWithSpace)
 	}
 }
 
@@ -123,10 +142,10 @@ type OrConditions struct {
 func (or OrConditions) Build(builder Builder) {
 	if len(or.Exprs) > 1 {
 		builder.WriteByte('(')
-		buildExprs(or.Exprs, builder, " OR ")
+		buildExprs(or.Exprs, builder, OrWithSpace)
 		builder.WriteByte(')')
 	} else {
-		buildExprs(or.Exprs, builder, " OR ")
+		buildExprs(or.Exprs, builder, OrWithSpace)
 	}
 }
 
@@ -134,6 +153,11 @@ func Not(exprs ...Expression) Expression {
 	if len(exprs) == 0 {
 		return nil
 	}
+	if len(exprs) == 1 {
+		if andCondition, ok := exprs[0].(AndConditions); ok {
+			exprs = andCondition.Exprs
+		}
+	}
 	return NotConditions{Exprs: exprs}
 }
 
@@ -142,23 +166,67 @@ type NotConditions struct {
 }
 
 func (not NotConditions) Build(builder Builder) {
-	if len(not.Exprs) > 1 {
-		builder.WriteByte('(')
+	anyNegationBuilder := false
+	for _, c := range not.Exprs {
+		if _, ok := c.(NegationExpressionBuilder); ok {
+			anyNegationBuilder = true
+			break
+		}
 	}
 
-	for idx, c := range not.Exprs {
-		if idx > 0 {
-			builder.WriteString(" AND ")
+	if anyNegationBuilder {
+		if len(not.Exprs) > 1 {
+			builder.WriteByte('(')
 		}
 
-		if negationBuilder, ok := c.(NegationExpressionBuilder); ok {
-			negationBuilder.NegationBuild(builder)
-		} else {
-			builder.WriteString("NOT ")
+		for idx, c := range not.Exprs {
+			if idx > 0 {
+				builder.WriteString(AndWithSpace)
+			}
+
+			if negationBuilder, ok := c.(NegationExpressionBuilder); ok {
+				negationBuilder.NegationBuild(builder)
+			} else {
+				builder.WriteString("NOT ")
+				e, wrapInParentheses := c.(Expr)
+				if wrapInParentheses {
+					sql := strings.ToUpper(e.SQL)
+					if wrapInParentheses = strings.Contains(sql, AndWithSpace) || strings.Contains(sql, OrWithSpace); wrapInParentheses {
+						builder.WriteByte('(')
+					}
+				}
+
+				c.Build(builder)
+
+				if wrapInParentheses {
+					builder.WriteByte(')')
+				}
+			}
+		}
+
+		if len(not.Exprs) > 1 {
+			builder.WriteByte(')')
+		}
+	} else {
+		builder.WriteString("NOT ")
+		if len(not.Exprs) > 1 {
+			builder.WriteByte('(')
+		}
+
+		for idx, c := range not.Exprs {
+			if idx > 0 {
+				switch c.(type) {
+				case OrConditions:
+					builder.WriteString(OrWithSpace)
+				default:
+					builder.WriteString(AndWithSpace)
+				}
+			}
+
 			e, wrapInParentheses := c.(Expr)
 			if wrapInParentheses {
-				sql := strings.ToLower(e.SQL)
-				if wrapInParentheses = strings.Contains(sql, "and") || strings.Contains(sql, "or"); wrapInParentheses {
+				sql := strings.ToUpper(e.SQL)
+				if wrapInParentheses = strings.Contains(sql, AndWithSpace) || strings.Contains(sql, OrWithSpace); wrapInParentheses {
 					builder.WriteByte('(')
 				}
 			}
@@ -169,9 +237,9 @@ func (not NotConditions) Build(builder Builder) {
 				builder.WriteByte(')')
 			}
 		}
-	}
 
-	if len(not.Exprs) > 1 {
-		builder.WriteByte(')')
+		if len(not.Exprs) > 1 {
+			builder.WriteByte(')')
+		}
 	}
 }

clause/where_test.go

@@ -17,25 +17,29 @@ func TestWhere(t *testing.T) {
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
 				Exprs: []clause.Expression{clause.Eq{Column: clause.PrimaryColumn, Value: "1"}, clause.Gt{Column: "age", Value: 18}, clause.Or(clause.Neq{Column: "name", Value: "jinzhu"})},
 			}},
-			"SELECT * FROM `users` WHERE `users`.`id` = ? AND `age` > ? OR `name` <> ?", []interface{}{"1", 18, "jinzhu"},
+			"SELECT * FROM `users` WHERE `users`.`id` = ? AND `age` > ? OR `name` <> ?",
+			[]interface{}{"1", 18, "jinzhu"},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
 				Exprs: []clause.Expression{clause.Or(clause.Neq{Column: "name", Value: "jinzhu"}), clause.Eq{Column: clause.PrimaryColumn, Value: "1"}, clause.Gt{Column: "age", Value: 18}},
 			}},
-			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ? AND `age` > ?", []interface{}{"1", "jinzhu", 18},
+			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ? AND `age` > ?",
+			[]interface{}{"1", "jinzhu", 18},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
 				Exprs: []clause.Expression{clause.Or(clause.Neq{Column: "name", Value: "jinzhu"}), clause.Eq{Column: clause.PrimaryColumn, Value: "1"}, clause.Gt{Column: "age", Value: 18}},
 			}},
-			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ? AND `age` > ?", []interface{}{"1", "jinzhu", 18},
+			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ? AND `age` > ?",
+			[]interface{}{"1", "jinzhu", 18},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
 				Exprs: []clause.Expression{clause.Or(clause.Eq{Column: clause.PrimaryColumn, Value: "1"}), clause.Or(clause.Neq{Column: "name", Value: "jinzhu"})},
 			}},
-			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ?", []interface{}{"1", "jinzhu"},
+			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ?",
+			[]interface{}{"1", "jinzhu"},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
@@ -43,7 +47,8 @@ func TestWhere(t *testing.T) {
 			}, clause.Where{
 				Exprs: []clause.Expression{clause.Or(clause.Gt{Column: "score", Value: 100}, clause.Like{Column: "name", Value: "%linus%"})},
 			}},
-			"SELECT * FROM `users` WHERE `users`.`id` = ? AND `age` > ? OR `name` <> ? AND (`score` > ? OR `name` LIKE ?)", []interface{}{"1", 18, "jinzhu", 100, "%linus%"},
+			"SELECT * FROM `users` WHERE `users`.`id` = ? AND `age` > ? OR `name` <> ? AND (`score` > ? OR `name` LIKE ?)",
+			[]interface{}{"1", 18, "jinzhu", 100, "%linus%"},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
@@ -51,13 +56,78 @@ func TestWhere(t *testing.T) {
 			}, clause.Where{
 				Exprs: []clause.Expression{clause.Or(clause.Not(clause.Gt{Column: "score", Value: 100}), clause.Like{Column: "name", Value: "%linus%"})},
 			}},
-			"SELECT * FROM `users` WHERE (`users`.`id` <> ? AND `age` <= ?) OR `name` <> ? AND (`score` <= ? OR `name` LIKE ?)", []interface{}{"1", 18, "jinzhu", 100, "%linus%"},
+			"SELECT * FROM `users` WHERE (`users`.`id` <> ? AND `age` <= ?) OR `name` <> ? AND (`score` <= ? OR `name` LIKE ?)",
+			[]interface{}{"1", 18, "jinzhu", 100, "%linus%"},
 		},
 		{
 			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
 				Exprs: []clause.Expression{clause.And(clause.Eq{Column: "age", Value: 18}, clause.Or(clause.Neq{Column: "name", Value: "jinzhu"}))},
 			}},
-			"SELECT * FROM `users` WHERE (`age` = ? OR `name` <> ?)", []interface{}{18, "jinzhu"},
+			"SELECT * FROM `users` WHERE `age` = ? OR `name` <> ?",
+			[]interface{}{18, "jinzhu"},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
+				Exprs: []clause.Expression{clause.Not(clause.Eq{Column: clause.PrimaryColumn, Value: "1"}, clause.Gt{Column: "age", Value: 18}), clause.And(clause.Expr{SQL: "`score` <= ?", Vars: []interface{}{100}, WithoutParentheses: false})},
+			}},
+			"SELECT * FROM `users` WHERE (`users`.`id` <> ? AND `age` <= ?) AND `score` <= ?",
+			[]interface{}{"1", 18, 100},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
+				Exprs: []clause.Expression{clause.Not(clause.Eq{Column: clause.PrimaryColumn, Value: "1"}, clause.Gt{Column: "age", Value: 18}), clause.Expr{SQL: "`score` <= ?", Vars: []interface{}{100}, WithoutParentheses: false}},
+			}},
+			"SELECT * FROM `users` WHERE (`users`.`id` <> ? AND `age` <= ?) AND `score` <= ?",
+			[]interface{}{"1", 18, 100},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
+				Exprs: []clause.Expression{clause.Not(clause.Eq{Column: clause.PrimaryColumn, Value: "1"}, clause.Gt{Column: "age", Value: 18}), clause.Or(clause.Expr{SQL: "`score` <= ?", Vars: []interface{}{100}, WithoutParentheses: false})},
+			}},
+			"SELECT * FROM `users` WHERE (`users`.`id` <> ? AND `age` <= ?) OR `score` <= ?",
+			[]interface{}{"1", 18, 100},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
+				Exprs: []clause.Expression{
+					clause.And(clause.Not(clause.Eq{Column: clause.PrimaryColumn, Value: "1"}),
+						clause.And(clause.Expr{SQL: "`score` <= ?", Vars: []interface{}{100}, WithoutParentheses: false})),
+				},
+			}},
+			"SELECT * FROM `users` WHERE `users`.`id` <> ? AND `score` <= ?",
+			[]interface{}{"1", 100},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
+				Exprs: []clause.Expression{clause.Not(clause.Eq{Column: clause.PrimaryColumn, Value: "1"},
+					clause.And(clause.Expr{SQL: "`score` <= ?", Vars: []interface{}{100}, WithoutParentheses: false}))},
+			}},
+			"SELECT * FROM `users` WHERE (`users`.`id` <> ? AND NOT `score` <= ?)",
+			[]interface{}{"1", 100},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
+				Exprs: []clause.Expression{clause.Not(clause.Expr{SQL: "`score` <= ?", Vars: []interface{}{100}},
+					clause.Expr{SQL: "`age` <= ?", Vars: []interface{}{60}})},
+			}},
+			"SELECT * FROM `users` WHERE NOT (`score` <= ? AND `age` <= ?)",
+			[]interface{}{100, 60},
+		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
+				Exprs: []clause.Expression{
+					clause.Not(clause.AndConditions{
+						Exprs: []clause.Expression{
+							clause.Eq{Column: clause.PrimaryColumn, Value: "1"},
+							clause.Gt{Column: "age", Value: 18},
+						}}, clause.OrConditions{
+						Exprs: []clause.Expression{
+							clause.Lt{Column: "score", Value: 100},
+						},
+					}),
+				}}},
+			"SELECT * FROM `users` WHERE NOT ((`users`.`id` = ? AND `age` > ?) OR `score` < ?)",
+			[]interface{}{"1", 18, 100},
 		},
 	}
 

clause/with.go

@@ -1,4 +1,3 @@
 package clause
 
-type With struct {
-}
+type With struct{}

errors.go

@@ -2,13 +2,15 @@ package gorm
 
 import (
 	"errors"
+
+	"gorm.io/gorm/logger"
 )
 
 var (
 	// ErrRecordNotFound record not found error
-	ErrRecordNotFound = errors.New("record not found")
+	ErrRecordNotFound = logger.ErrRecordNotFound
 	// ErrInvalidTransaction invalid transaction when you are trying to `Commit` or `Rollback`
-	ErrInvalidTransaction = errors.New("no valid transaction")
+	ErrInvalidTransaction = errors.New("invalid transaction")
 	// ErrNotImplemented not implemented
 	ErrNotImplemented = errors.New("not implemented")
 	// ErrMissingWhereClause missing where clause
@@ -19,6 +21,10 @@ var (
 	ErrPrimaryKeyRequired = errors.New("primary key required")
 	// ErrModelValueRequired model value required
 	ErrModelValueRequired = errors.New("model value required")
+	// ErrModelAccessibleFieldsRequired model accessible fields required
+	ErrModelAccessibleFieldsRequired = errors.New("model accessible fields required")
+	// ErrSubQueryRequired sub query required
+	ErrSubQueryRequired = errors.New("sub query required")
 	// ErrInvalidData unsupported data
 	ErrInvalidData = errors.New("unsupported data")
 	// ErrUnsupportedDriver unsupported driver
@@ -31,10 +37,18 @@ var (
 	ErrEmptySlice = errors.New("empty slice found")
 	// ErrDryRunModeUnsupported dry run mode unsupported
 	ErrDryRunModeUnsupported = errors.New("dry run mode unsupported")
-	// ErrInvaildDB invalid db
-	ErrInvaildDB = errors.New("invalid db")
+	// ErrInvalidDB invalid db
+	ErrInvalidDB = errors.New("invalid db")
 	// ErrInvalidValue invalid value
-	ErrInvalidValue = errors.New("invalid value")
+	ErrInvalidValue = errors.New("invalid value, should be pointer to struct or slice")
 	// ErrInvalidValueOfLength invalid values do not match length
 	ErrInvalidValueOfLength = errors.New("invalid association values, length doesn't match")
+	// ErrPreloadNotAllowed preload is not allowed when count is used
+	ErrPreloadNotAllowed = errors.New("preload is not allowed when count is used")
+	// ErrDuplicatedKey occurs when there is a unique key constraint violation
+	ErrDuplicatedKey = errors.New("duplicated key not allowed")
+	// ErrForeignKeyViolated occurs when there is a foreign key constraint violation
+	ErrForeignKeyViolated = errors.New("violates foreign key constraint")
+	// ErrCheckConstraintViolated occurs when there is a check constraint violation
+	ErrCheckConstraintViolated = errors.New("violates check constraint")
 )

finisher_api.go

@@ -1,9 +1,11 @@
 package gorm
 
 import (
+	"context"
 	"database/sql"
 	"errors"
 	"fmt"
+	"hash/maphash"
 	"reflect"
 	"strings"
 
@@ -13,7 +15,7 @@ import (
 	"gorm.io/gorm/utils"
 )
 
-// Create insert the value into database
+// Create inserts value, returning the inserted data's primary key in value's id
 func (db *DB) Create(value interface{}) (tx *DB) {
 	if db.CreateBatchSize > 0 {
 		return db.CreateInBatches(value, db.CreateBatchSize)
@@ -21,11 +23,10 @@ func (db *DB) Create(value interface{}) (tx *DB) {
 
 	tx = db.getInstance()
 	tx.Statement.Dest = value
-	tx.callbacks.Create().Execute(tx)
-	return
+	return tx.callbacks.Create().Execute(tx)
 }
 
-// CreateInBatches insert the value in batches into database
+// CreateInBatches inserts value in batches of batchSize
 func (db *DB) CreateInBatches(value interface{}, batchSize int) (tx *DB) {
 	reflectValue := reflect.Indirect(reflect.ValueOf(value))
 
@@ -34,9 +35,10 @@ func (db *DB) CreateInBatches(value interface{}, batchSize int) (tx *DB) {
 		var rowsAffected int64
 		tx = db.getInstance()
 
+		// the reflection length judgment of the optimized value
+		reflectLen := reflectValue.Len()
+
 		callFc := func(tx *DB) error {
-			// the reflection length judgment of the optimized value
-			reflectLen := reflectValue.Len()
 			for i := 0; i < reflectLen; i += batchSize {
 				ends := i + batchSize
 				if ends > reflectLen {
@@ -54,7 +56,7 @@ func (db *DB) CreateInBatches(value interface{}, batchSize int) (tx *DB) {
 			return nil
 		}
 
-		if tx.SkipDefaultTransaction {
+		if tx.SkipDefaultTransaction || reflectLen <= batchSize {
 			tx.AddError(callFc(tx.Session(&Session{})))
 		} else {
 			tx.AddError(tx.Transaction(callFc))
@@ -64,29 +66,32 @@ func (db *DB) CreateInBatches(value interface{}, batchSize int) (tx *DB) {
 	default:
 		tx = db.getInstance()
 		tx.Statement.Dest = value
-		tx.callbacks.Create().Execute(tx)
+		tx = tx.callbacks.Create().Execute(tx)
 	}
 	return
 }
 
-// Save update value in database, if the value doesn't have primary key, will insert it
+// Save updates value in database. If value doesn't contain a matching primary key, value is inserted.
 func (db *DB) Save(value interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Dest = value
 
 	reflectValue := reflect.Indirect(reflect.ValueOf(value))
+	for reflectValue.Kind() == reflect.Ptr || reflectValue.Kind() == reflect.Interface {
+		reflectValue = reflect.Indirect(reflectValue)
+	}
+
 	switch reflectValue.Kind() {
 	case reflect.Slice, reflect.Array:
 		if _, ok := tx.Statement.Clauses["ON CONFLICT"]; !ok {
 			tx = tx.Clauses(clause.OnConflict{UpdateAll: true})
 		}
-		tx.callbacks.Create().Execute(tx.InstanceSet("gorm:update_track_time", true))
+		tx = tx.callbacks.Create().Execute(tx.Set("gorm:update_track_time", true))
 	case reflect.Struct:
 		if err := tx.Statement.Parse(value); err == nil && tx.Statement.Schema != nil {
 			for _, pf := range tx.Statement.Schema.PrimaryFields {
-				if _, isZero := pf.ValueOf(reflectValue); isZero {
-					tx.callbacks.Create().Execute(tx)
-					return
+				if _, isZero := pf.ValueOf(tx.Statement.Context, reflectValue); isZero {
+					return tx.callbacks.Create().Execute(tx)
 				}
 			}
 		}
@@ -99,20 +104,19 @@ func (db *DB) Save(value interface{}) (tx *DB) {
 			tx.Statement.Selects = append(tx.Statement.Selects, "*")
 		}
 
-		tx.callbacks.Update().Execute(tx)
+		updateTx := tx.callbacks.Update().Execute(tx.Session(&Session{Initialized: true}))
 
-		if tx.Error == nil && tx.RowsAffected == 0 && !tx.DryRun && !selectedUpdate {
-			result := reflect.New(tx.Statement.Schema.ModelType).Interface()
-			if err := tx.Session(&Session{}).First(result).Error; errors.Is(err, ErrRecordNotFound) {
-				return tx.Create(value)
-			}
+		if updateTx.Error == nil && updateTx.RowsAffected == 0 && !updateTx.DryRun && !selectedUpdate {
+			return tx.Session(&Session{SkipHooks: true}).Clauses(clause.OnConflict{UpdateAll: true}).Create(value)
 		}
+
+		return updateTx
 	}
 
 	return
 }
 
-// First find first record that match given conditions, order by primary key
+// First finds the first record ordered by primary key, matching given conditions conds
 func (db *DB) First(dest interface{}, conds ...interface{}) (tx *DB) {
 	tx = db.Limit(1).Order(clause.OrderByColumn{
 		Column: clause.Column{Table: clause.CurrentTable, Name: clause.PrimaryKey},
@@ -124,11 +128,10 @@ func (db *DB) First(dest interface{}, conds ...interface{}) (tx *DB) {
 	}
 	tx.Statement.RaiseErrorOnNotFound = true
 	tx.Statement.Dest = dest
-	tx.callbacks.Query().Execute(tx)
-	return
+	return tx.callbacks.Query().Execute(tx)
 }
 
-// Take return a record that match given conditions, the order will depend on the database implementation
+// Take finds the first record returned by the database in no specified order, matching given conditions conds
 func (db *DB) Take(dest interface{}, conds ...interface{}) (tx *DB) {
 	tx = db.Limit(1)
 	if len(conds) > 0 {
@@ -138,11 +141,10 @@ func (db *DB) Take(dest interface{}, conds ...interface{}) (tx *DB) {
 	}
 	tx.Statement.RaiseErrorOnNotFound = true
 	tx.Statement.Dest = dest
-	tx.callbacks.Query().Execute(tx)
-	return
+	return tx.callbacks.Query().Execute(tx)
 }
 
-// Last find last record that match given conditions, order by primary key
+// Last finds the last record ordered by primary key, matching given conditions conds
 func (db *DB) Last(dest interface{}, conds ...interface{}) (tx *DB) {
 	tx = db.Limit(1).Order(clause.OrderByColumn{
 		Column: clause.Column{Table: clause.CurrentTable, Name: clause.PrimaryKey},
@@ -155,11 +157,10 @@ func (db *DB) Last(dest interface{}, conds ...interface{}) (tx *DB) {
 	}
 	tx.Statement.RaiseErrorOnNotFound = true
 	tx.Statement.Dest = dest
-	tx.callbacks.Query().Execute(tx)
-	return
+	return tx.callbacks.Query().Execute(tx)
 }
 
-// Find find records that match given conditions
+// Find finds all records matching given conditions conds
 func (db *DB) Find(dest interface{}, conds ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	if len(conds) > 0 {
@@ -168,11 +169,10 @@ func (db *DB) Find(dest interface{}, conds ...interface{}) (tx *DB) {
 		}
 	}
 	tx.Statement.Dest = dest
-	tx.callbacks.Query().Execute(tx)
-	return
+	return tx.callbacks.Query().Execute(tx)
 }
 
-// FindInBatches find records in batches
+// FindInBatches finds all records in batches of batchSize
 func (db *DB) FindInBatches(dest interface{}, batchSize int, fc func(tx *DB, batch int) error) *DB {
 	var (
 		tx = db.Order(clause.OrderByColumn{
@@ -183,34 +183,69 @@ func (db *DB) FindInBatches(dest interface{}, batchSize int, fc func(tx *DB, bat
 		batch        int
 	)
 
+	// user specified offset or limit
+	var totalSize int
+	if c, ok := tx.Statement.Clauses["LIMIT"]; ok {
+		if limit, ok := c.Expression.(clause.Limit); ok {
+			if limit.Limit != nil {
+				totalSize = *limit.Limit
+			}
+
+			if totalSize > 0 && batchSize > totalSize {
+				batchSize = totalSize
+			}
+
+			// reset to offset to 0 in next batch
+			tx = tx.Offset(-1).Session(&Session{})
+		}
+	}
+
 	for {
 		result := queryDB.Limit(batchSize).Find(dest)
 		rowsAffected += result.RowsAffected
 		batch++
 
 		if result.Error == nil && result.RowsAffected != 0 {
-			tx.AddError(fc(result, batch))
+			fcTx := result.Session(&Session{NewDB: true})
+			fcTx.RowsAffected = result.RowsAffected
+			tx.AddError(fc(fcTx, batch))
+		} else if result.Error != nil {
+			tx.AddError(result.Error)
 		}
 
 		if tx.Error != nil || int(result.RowsAffected) < batchSize {
 			break
-		} else {
-			resultsValue := reflect.Indirect(reflect.ValueOf(dest))
-			if result.Statement.Schema.PrioritizedPrimaryField == nil {
-				tx.AddError(ErrPrimaryKeyRequired)
+		}
+
+		if totalSize > 0 {
+			if totalSize <= int(rowsAffected) {
 				break
-			} else {
-				primaryValue, _ := result.Statement.Schema.PrioritizedPrimaryField.ValueOf(resultsValue.Index(resultsValue.Len() - 1))
-				queryDB = tx.Clauses(clause.Gt{Column: clause.Column{Table: clause.CurrentTable, Name: clause.PrimaryKey}, Value: primaryValue})
+			}
+			if totalSize/batchSize == batch {
+				batchSize = totalSize % batchSize
 			}
 		}
+
+		// Optimize for-break
+		resultsValue := reflect.Indirect(reflect.ValueOf(dest))
+		if result.Statement.Schema.PrioritizedPrimaryField == nil {
+			tx.AddError(ErrPrimaryKeyRequired)
+			break
+		}
+
+		primaryValue, zero := result.Statement.Schema.PrioritizedPrimaryField.ValueOf(tx.Statement.Context, resultsValue.Index(resultsValue.Len()-1))
+		if zero {
+			tx.AddError(ErrPrimaryKeyRequired)
+			break
+		}
+		queryDB = tx.Clauses(clause.Gt{Column: clause.Column{Table: clause.CurrentTable, Name: clause.PrimaryKey}, Value: primaryValue})
 	}
 
 	tx.RowsAffected = rowsAffected
 	return tx
 }
 
-func (tx *DB) assignInterfacesToValue(values ...interface{}) {
+func (db *DB) assignInterfacesToValue(values ...interface{}) {
 	for _, value := range values {
 		switch v := value.(type) {
 		case []clause.Expression:
@@ -218,40 +253,40 @@ func (tx *DB) assignInterfacesToValue(values ...interface{}) {
 				if eq, ok := expr.(clause.Eq); ok {
 					switch column := eq.Column.(type) {
 					case string:
-						if field := tx.Statement.Schema.LookUpField(column); field != nil {
-							tx.AddError(field.Set(tx.Statement.ReflectValue, eq.Value))
+						if field := db.Statement.Schema.LookUpField(column); field != nil {
+							db.AddError(field.Set(db.Statement.Context, db.Statement.ReflectValue, eq.Value))
 						}
 					case clause.Column:
-						if field := tx.Statement.Schema.LookUpField(column.Name); field != nil {
-							tx.AddError(field.Set(tx.Statement.ReflectValue, eq.Value))
+						if field := db.Statement.Schema.LookUpField(column.Name); field != nil {
+							db.AddError(field.Set(db.Statement.Context, db.Statement.ReflectValue, eq.Value))
 						}
 					}
 				} else if andCond, ok := expr.(clause.AndConditions); ok {
-					tx.assignInterfacesToValue(andCond.Exprs)
+					db.assignInterfacesToValue(andCond.Exprs)
 				}
 			}
 		case clause.Expression, map[string]string, map[interface{}]interface{}, map[string]interface{}:
-			if exprs := tx.Statement.BuildCondition(value); len(exprs) > 0 {
-				tx.assignInterfacesToValue(exprs)
+			if exprs := db.Statement.BuildCondition(value); len(exprs) > 0 {
+				db.assignInterfacesToValue(exprs)
 			}
 		default:
-			if s, err := schema.Parse(value, tx.cacheStore, tx.NamingStrategy); err == nil {
+			if s, err := schema.Parse(value, db.cacheStore, db.NamingStrategy); err == nil {
 				reflectValue := reflect.Indirect(reflect.ValueOf(value))
 				switch reflectValue.Kind() {
 				case reflect.Struct:
 					for _, f := range s.Fields {
 						if f.Readable {
-							if v, isZero := f.ValueOf(reflectValue); !isZero {
-								if field := tx.Statement.Schema.LookUpField(f.Name); field != nil {
-									tx.AddError(field.Set(tx.Statement.ReflectValue, v))
+							if v, isZero := f.ValueOf(db.Statement.Context, reflectValue); !isZero {
+								if field := db.Statement.Schema.LookUpField(f.Name); field != nil {
+									db.AddError(field.Set(db.Statement.Context, db.Statement.ReflectValue, v))
 								}
 							}
 						}
 					}
 				}
 			} else if len(values) > 0 {
-				if exprs := tx.Statement.BuildCondition(values[0], values[1:]...); len(exprs) > 0 {
-					tx.assignInterfacesToValue(exprs)
+				if exprs := db.Statement.BuildCondition(values[0], values[1:]...); len(exprs) > 0 {
+					db.assignInterfacesToValue(exprs)
 				}
 				return
 			}
@@ -259,12 +294,24 @@ func (tx *DB) assignInterfacesToValue(values ...interface{}) {
 	}
 }
 
+// FirstOrInit finds the first matching record, otherwise if not found initializes a new instance with given conds.
+// Each conds must be a struct or map.
+//
+// FirstOrInit never modifies the database. It is often used with Assign and Attrs.
+//
+//	// assign an email if the record is not found
+//	db.Where(User{Name: "non_existing"}).Attrs(User{Email: "fake@fake.org"}).FirstOrInit(&user)
+//	// user -> User{Name: "non_existing", Email: "fake@fake.org"}
+//
+//	// assign email regardless of if record is found
+//	db.Where(User{Name: "jinzhu"}).Assign(User{Email: "fake@fake.org"}).FirstOrInit(&user)
+//	// user -> User{Name: "jinzhu", Age: 20, Email: "fake@fake.org"}
 func (db *DB) FirstOrInit(dest interface{}, conds ...interface{}) (tx *DB) {
 	queryTx := db.Limit(1).Order(clause.OrderByColumn{
 		Column: clause.Column{Table: clause.CurrentTable, Name: clause.PrimaryKey},
 	})
 
-	if tx = queryTx.Find(dest, conds...); queryTx.RowsAffected == 0 {
+	if tx = queryTx.Find(dest, conds...); tx.RowsAffected == 0 {
 		if c, ok := tx.Statement.Clauses["WHERE"]; ok {
 			if where, ok := c.Expression.(clause.Where); ok {
 				tx.assignInterfacesToValue(where.Exprs)
@@ -284,40 +331,64 @@ func (db *DB) FirstOrInit(dest interface{}, conds ...interface{}) (tx *DB) {
 	return
 }
 
+// FirstOrCreate finds the first matching record, otherwise if not found creates a new instance with given conds.
+// Each conds must be a struct or map.
+//
+// Using FirstOrCreate in conjunction with Assign will result in an update to the database even if the record exists.
+//
+//	// assign an email if the record is not found
+//	result := db.Where(User{Name: "non_existing"}).Attrs(User{Email: "fake@fake.org"}).FirstOrCreate(&user)
+//	// user -> User{Name: "non_existing", Email: "fake@fake.org"}
+//	// result.RowsAffected -> 1
+//
+//	// assign email regardless of if record is found
+//	result := db.Where(User{Name: "jinzhu"}).Assign(User{Email: "fake@fake.org"}).FirstOrCreate(&user)
+//	// user -> User{Name: "jinzhu", Age: 20, Email: "fake@fake.org"}
+//	// result.RowsAffected -> 1
 func (db *DB) FirstOrCreate(dest interface{}, conds ...interface{}) (tx *DB) {
-	queryTx := db.Limit(1).Order(clause.OrderByColumn{
+	tx = db.getInstance()
+	queryTx := db.Session(&Session{}).Limit(1).Order(clause.OrderByColumn{
 		Column: clause.Column{Table: clause.CurrentTable, Name: clause.PrimaryKey},
 	})
 
-	if tx = queryTx.Find(dest, conds...); queryTx.RowsAffected == 0 {
-		if c, ok := tx.Statement.Clauses["WHERE"]; ok {
+	result := queryTx.Find(dest, conds...)
+	if result.Error != nil {
+		tx.Error = result.Error
+		return tx
+	}
+
+	if result.RowsAffected == 0 {
+		if c, ok := result.Statement.Clauses["WHERE"]; ok {
 			if where, ok := c.Expression.(clause.Where); ok {
-				tx.assignInterfacesToValue(where.Exprs)
+				result.assignInterfacesToValue(where.Exprs)
 			}
 		}
 
 		// initialize with attrs, conds
-		if len(tx.Statement.attrs) > 0 {
-			tx.assignInterfacesToValue(tx.Statement.attrs...)
+		if len(db.Statement.attrs) > 0 {
+			result.assignInterfacesToValue(db.Statement.attrs...)
 		}
 
 		// initialize with attrs, conds
-		if len(tx.Statement.assigns) > 0 {
-			tx.assignInterfacesToValue(tx.Statement.assigns...)
+		if len(db.Statement.assigns) > 0 {
+			result.assignInterfacesToValue(db.Statement.assigns...)
 		}
 
 		return tx.Create(dest)
 	} else if len(db.Statement.assigns) > 0 {
-		exprs := tx.Statement.BuildCondition(tx.Statement.assigns[0], tx.Statement.assigns[1:]...)
+		exprs := tx.Statement.BuildCondition(db.Statement.assigns[0], db.Statement.assigns[1:]...)
 		assigns := map[string]interface{}{}
-		for _, expr := range exprs {
-			if eq, ok := expr.(clause.Eq); ok {
+		for i := 0; i < len(exprs); i++ {
+			expr := exprs[i]
+
+			if eq, ok := expr.(clause.AndConditions); ok {
+				exprs = append(exprs, eq.Exprs...)
+			} else if eq, ok := expr.(clause.Eq); ok {
 				switch column := eq.Column.(type) {
 				case string:
 					assigns[column] = eq.Value
 				case clause.Column:
 					assigns[column.Name] = eq.Value
-				default:
 				}
 			}
 		}
@@ -325,42 +396,40 @@ func (db *DB) FirstOrCreate(dest interface{}, conds ...interface{}) (tx *DB) {
 		return tx.Model(dest).Updates(assigns)
 	}
 
-	return db
+	return tx
 }
 
-// Update update attributes with callbacks, refer: https://gorm.io/docs/update.html#Update-Changed-Fields
+// Update updates column with value using callbacks. Reference: https://gorm.io/docs/update.html#Update-Changed-Fields
 func (db *DB) Update(column string, value interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Dest = map[string]interface{}{column: value}
-	tx.callbacks.Update().Execute(tx)
-	return
+	return tx.callbacks.Update().Execute(tx)
 }
 
-// Updates update attributes with callbacks, refer: https://gorm.io/docs/update.html#Update-Changed-Fields
+// Updates updates attributes using callbacks. values must be a struct or map. Reference: https://gorm.io/docs/update.html#Update-Changed-Fields
 func (db *DB) Updates(values interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Dest = values
-	tx.callbacks.Update().Execute(tx)
-	return
+	return tx.callbacks.Update().Execute(tx)
 }
 
 func (db *DB) UpdateColumn(column string, value interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Dest = map[string]interface{}{column: value}
 	tx.Statement.SkipHooks = true
-	tx.callbacks.Update().Execute(tx)
-	return
+	return tx.callbacks.Update().Execute(tx)
 }
 
 func (db *DB) UpdateColumns(values interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.Dest = values
 	tx.Statement.SkipHooks = true
-	tx.callbacks.Update().Execute(tx)
-	return
+	return tx.callbacks.Update().Execute(tx)
 }
 
-// Delete delete value match given conditions, if the value has primary key, then will including the primary key as condition
+// Delete deletes value matching given conditions. If value contains primary key it is included in the conditions. If
+// value includes a deleted_at field, then Delete performs a soft delete instead by setting deleted_at with the current
+// time if null.
 func (db *DB) Delete(value interface{}, conds ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	if len(conds) > 0 {
@@ -369,8 +438,7 @@ func (db *DB) Delete(value interface{}, conds ...interface{}) (tx *DB) {
 		}
 	}
 	tx.Statement.Dest = value
-	tx.callbacks.Delete().Execute(tx)
-	return
+	return tx.callbacks.Delete().Execute(tx)
 }
 
 func (db *DB) Count(count *int64) (tx *DB) {
@@ -384,21 +452,21 @@ func (db *DB) Count(count *int64) (tx *DB) {
 
 	if selectClause, ok := db.Statement.Clauses["SELECT"]; ok {
 		defer func() {
-			db.Statement.Clauses["SELECT"] = selectClause
+			tx.Statement.Clauses["SELECT"] = selectClause
 		}()
 	} else {
 		defer delete(tx.Statement.Clauses, "SELECT")
 	}
 
 	if len(tx.Statement.Selects) == 0 {
-		tx.Statement.AddClause(clause.Select{Expression: clause.Expr{SQL: "count(1)"}})
+		tx.Statement.AddClause(clause.Select{Expression: clause.Expr{SQL: "count(*)"}})
 	} else if !strings.HasPrefix(strings.TrimSpace(strings.ToLower(tx.Statement.Selects[0])), "count(") {
-		expr := clause.Expr{SQL: "count(1)"}
+		expr := clause.Expr{SQL: "count(*)"}
 
 		if len(tx.Statement.Selects) == 1 {
 			dbName := tx.Statement.Selects[0]
 			fields := strings.FieldsFunc(dbName, utils.IsValidDBNameChar)
-			if len(fields) == 1 || (len(fields) == 3 && strings.ToUpper(fields[1]) == "AS") {
+			if len(fields) == 1 || (len(fields) == 3 && (strings.ToUpper(fields[1]) == "AS" || fields[1] == ".")) {
 				if tx.Statement.Parse(tx.Statement.Model) == nil {
 					if f := tx.Statement.Schema.LookUpField(dbName); f != nil {
 						dbName = f.DBName
@@ -407,7 +475,7 @@ func (db *DB) Count(count *int64) (tx *DB) {
 
 				if tx.Statement.Distinct {
 					expr = clause.Expr{SQL: "COUNT(DISTINCT(?))", Vars: []interface{}{clause.Column{Name: dbName}}}
-				} else {
+				} else if dbName != "*" {
 					expr = clause.Expr{SQL: "COUNT(?)", Vars: []interface{}{clause.Column{Name: dbName}}}
 				}
 			}
@@ -418,24 +486,26 @@ func (db *DB) Count(count *int64) (tx *DB) {
 
 	if orderByClause, ok := db.Statement.Clauses["ORDER BY"]; ok {
 		if _, ok := db.Statement.Clauses["GROUP BY"]; !ok {
-			delete(db.Statement.Clauses, "ORDER BY")
+			delete(tx.Statement.Clauses, "ORDER BY")
 			defer func() {
-				db.Statement.Clauses["ORDER BY"] = orderByClause
+				tx.Statement.Clauses["ORDER BY"] = orderByClause
 			}()
 		}
 	}
 
 	tx.Statement.Dest = count
-	tx.callbacks.Query().Execute(tx)
-	if tx.RowsAffected != 1 {
+	tx = tx.callbacks.Query().Execute(tx)
+
+	if _, ok := db.Statement.Clauses["GROUP BY"]; ok || tx.RowsAffected != 1 {
 		*count = tx.RowsAffected
 	}
+
 	return
 }
 
 func (db *DB) Row() *sql.Row {
-	tx := db.getInstance().InstanceSet("rows", false)
-	tx.callbacks.Row().Execute(tx)
+	tx := db.getInstance().Set("rows", false)
+	tx = tx.callbacks.Row().Execute(tx)
 	row, ok := tx.Statement.Dest.(*sql.Row)
 	if !ok && tx.DryRun {
 		db.Logger.Error(tx.Statement.Context, ErrDryRunModeUnsupported.Error())
@@ -444,8 +514,8 @@ func (db *DB) Row() *sql.Row {
 }
 
 func (db *DB) Rows() (*sql.Rows, error) {
-	tx := db.getInstance().InstanceSet("rows", true)
-	tx.callbacks.Row().Execute(tx)
+	tx := db.getInstance().Set("rows", true)
+	tx = tx.callbacks.Row().Execute(tx)
 	rows, ok := tx.Statement.Dest.(*sql.Rows)
 	if !ok && tx.DryRun && tx.Error == nil {
 		tx.Error = ErrDryRunModeUnsupported
@@ -453,7 +523,7 @@ func (db *DB) Rows() (*sql.Rows, error) {
 	return rows, tx.Error
 }
 
-// Scan scan value to a struct
+// Scan scans selected value to the struct dest
 func (db *DB) Scan(dest interface{}) (tx *DB) {
 	config := *db.Config
 	currentLogger, newLogger := config.Logger, logger.Recorder.New()
@@ -462,15 +532,14 @@ func (db *DB) Scan(dest interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Config = &config
 
-	if rows, err := tx.Rows(); err != nil {
-		tx.AddError(err)
-	} else {
-		defer rows.Close()
+	if rows, err := tx.Rows(); err == nil {
 		if rows.Next() {
 			tx.ScanRows(rows, dest)
 		} else {
 			tx.RowsAffected = 0
+			tx.AddError(rows.Err())
 		}
+		tx.AddError(rows.Close())
 	}
 
 	currentLogger.Trace(tx.Statement.Context, newLogger.BeginAt, func() (string, int64) {
@@ -480,9 +549,10 @@ func (db *DB) Scan(dest interface{}) (tx *DB) {
 	return
 }
 
-// Pluck used to query single column from a model as a map
-//     var ages []int64
-//     db.Find(&users).Pluck("age", &ages)
+// Pluck queries a single column from a model, returning in the slice dest. E.g.:
+//
+//	var ages []int64
+//	db.Model(&users).Pluck("age", &ages)
 func (db *DB) Pluck(column string, dest interface{}) (tx *DB) {
 	tx = db.getInstance()
 	if tx.Statement.Model != nil {
@@ -491,8 +561,6 @@ func (db *DB) Pluck(column string, dest interface{}) (tx *DB) {
 				column = f.DBName
 			}
 		}
-	} else if tx.Statement.Table == "" {
-		tx.AddError(ErrModelValueRequired)
 	}
 
 	if len(tx.Statement.Selects) != 1 {
@@ -503,8 +571,7 @@ func (db *DB) Pluck(column string, dest interface{}) (tx *DB) {
 		})
 	}
 	tx.Statement.Dest = dest
-	tx.callbacks.Query().Execute(tx)
-	return
+	return tx.callbacks.Query().Execute(tx)
 }
 
 func (db *DB) ScanRows(rows *sql.Rows, dest interface{}) error {
@@ -515,33 +582,67 @@ func (db *DB) ScanRows(rows *sql.Rows, dest interface{}) error {
 	tx.Statement.Dest = dest
 	tx.Statement.ReflectValue = reflect.ValueOf(dest)
 	for tx.Statement.ReflectValue.Kind() == reflect.Ptr {
-		tx.Statement.ReflectValue = tx.Statement.ReflectValue.Elem()
+		elem := tx.Statement.ReflectValue.Elem()
+		if !elem.IsValid() {
+			elem = reflect.New(tx.Statement.ReflectValue.Type().Elem())
+			tx.Statement.ReflectValue.Set(elem)
+		}
+		tx.Statement.ReflectValue = elem
 	}
-	Scan(rows, tx, true)
+	Scan(rows, tx, ScanInitialized)
 	return tx.Error
 }
 
-// Transaction start a transaction as a block, return error will rollback, otherwise to commit.
+// Connection uses a db connection to execute an arbitrary number of commands in fc. When finished, the connection is
+// returned to the connection pool.
+func (db *DB) Connection(fc func(tx *DB) error) (err error) {
+	if db.Error != nil {
+		return db.Error
+	}
+
+	tx := db.getInstance()
+	sqlDB, err := tx.DB()
+	if err != nil {
+		return
+	}
+
+	conn, err := sqlDB.Conn(tx.Statement.Context)
+	if err != nil {
+		return
+	}
+
+	defer conn.Close()
+	tx.Statement.ConnPool = conn
+	return fc(tx)
+}
+
+// Transaction start a transaction as a block, return error will rollback, otherwise to commit. Transaction executes an
+// arbitrary number of commands in fc within a transaction. On success the changes are committed; if an error occurs
+// they are rolled back.
 func (db *DB) Transaction(fc func(tx *DB) error, opts ...*sql.TxOptions) (err error) {
 	panicked := true
 
 	if committer, ok := db.Statement.ConnPool.(TxCommitter); ok && committer != nil {
 		// nested transaction
 		if !db.DisableNestedTransaction {
-			err = db.SavePoint(fmt.Sprintf("sp%p", fc)).Error
+			spID := new(maphash.Hash).Sum64()
+			err = db.SavePoint(fmt.Sprintf("sp%d", spID)).Error
+			if err != nil {
+				return
+			}
 			defer func() {
 				// Make sure to rollback when panic, Block error or Commit error
 				if panicked || err != nil {
-					db.RollbackTo(fmt.Sprintf("sp%p", fc))
+					db.RollbackTo(fmt.Sprintf("sp%d", spID))
 				}
 			}()
 		}
-
-		if err == nil {
-			err = fc(db.Session(&Session{}))
-		}
+		err = fc(db.Session(&Session{NewDB: db.clone == 1}))
 	} else {
 		tx := db.Begin(opts...)
+		if tx.Error != nil {
+			return tx.Error
+		}
 
 		defer func() {
 			// Make sure to rollback when panic, Block error or Commit error
@@ -550,12 +651,9 @@ func (db *DB) Transaction(fc func(tx *DB) error, opts ...*sql.TxOptions) (err er
 			}
 		}()
 
-		if err = tx.Error; err == nil {
-			err = fc(tx)
-		}
-
-		if err == nil {
-			err = tx.Commit().Error
+		if err = fc(tx); err == nil {
+			panicked = false
+			return tx.Commit().Error
 		}
 	}
 
@@ -563,11 +661,11 @@ func (db *DB) Transaction(fc func(tx *DB) error, opts ...*sql.TxOptions) (err er
 	return
 }
 
-// Begin begins a transaction
+// Begin begins a transaction with any transaction options opts
 func (db *DB) Begin(opts ...*sql.TxOptions) *DB {
 	var (
 		// clone statement
-		tx  = db.getInstance().Session(&Session{Context: db.Statement.Context})
+		tx  = db.getInstance().Session(&Session{Context: db.Statement.Context, NewDB: db.clone == 1})
 		opt *sql.TxOptions
 		err error
 	)
@@ -576,11 +674,19 @@ func (db *DB) Begin(opts ...*sql.TxOptions) *DB {
 		opt = opts[0]
 	}
 
-	if beginner, ok := tx.Statement.ConnPool.(TxBeginner); ok {
-		tx.Statement.ConnPool, err = beginner.BeginTx(tx.Statement.Context, opt)
-	} else if beginner, ok := tx.Statement.ConnPool.(ConnPoolBeginner); ok {
-		tx.Statement.ConnPool, err = beginner.BeginTx(tx.Statement.Context, opt)
-	} else {
+	ctx := tx.Statement.Context
+	if _, ok := ctx.Deadline(); !ok {
+		if db.Config.DefaultTransactionTimeout > 0 {
+			ctx, _ = context.WithTimeout(ctx, db.Config.DefaultTransactionTimeout)
+		}
+	}
+
+	switch beginner := tx.Statement.ConnPool.(type) {
+	case TxBeginner:
+		tx.Statement.ConnPool, err = beginner.BeginTx(ctx, opt)
+	case ConnPoolBeginner:
+		tx.Statement.ConnPool, err = beginner.BeginTx(ctx, opt)
+	default:
 		err = ErrInvalidTransaction
 	}
 
@@ -591,7 +697,7 @@ func (db *DB) Begin(opts ...*sql.TxOptions) *DB {
 	return tx
 }
 
-// Commit commit a transaction
+// Commit commits the changes in a transaction
 func (db *DB) Commit() *DB {
 	if committer, ok := db.Statement.ConnPool.(TxCommitter); ok && committer != nil && !reflect.ValueOf(committer).IsNil() {
 		db.AddError(committer.Commit())
@@ -601,7 +707,7 @@ func (db *DB) Commit() *DB {
 	return db
 }
 
-// Rollback rollback a transaction
+// Rollback rollbacks the changes in a transaction
 func (db *DB) Rollback() *DB {
 	if committer, ok := db.Statement.ConnPool.(TxCommitter); ok && committer != nil {
 		if !reflect.ValueOf(committer).IsNil() {
@@ -615,7 +721,21 @@ func (db *DB) Rollback() *DB {
 
 func (db *DB) SavePoint(name string) *DB {
 	if savePointer, ok := db.Dialector.(SavePointerDialectorInterface); ok {
+		// close prepared statement, because SavePoint not support prepared statement.
+		// e.g. mysql8.0 doc: https://dev.mysql.com/doc/refman/8.0/en/sql-prepared-statements.html
+		var (
+			preparedStmtTx   *PreparedStmtTX
+			isPreparedStmtTx bool
+		)
+		// close prepared statement, because SavePoint not support prepared statement.
+		if preparedStmtTx, isPreparedStmtTx = db.Statement.ConnPool.(*PreparedStmtTX); isPreparedStmtTx {
+			db.Statement.ConnPool = preparedStmtTx.Tx
+		}
 		db.AddError(savePointer.SavePoint(db, name))
+		// restore prepared statement
+		if isPreparedStmtTx {
+			db.Statement.ConnPool = preparedStmtTx
+		}
 	} else {
 		db.AddError(ErrUnsupportedDriver)
 	}
@@ -624,14 +744,28 @@ func (db *DB) SavePoint(name string) *DB {
 
 func (db *DB) RollbackTo(name string) *DB {
 	if savePointer, ok := db.Dialector.(SavePointerDialectorInterface); ok {
+		// close prepared statement, because RollbackTo not support prepared statement.
+		// e.g. mysql8.0 doc: https://dev.mysql.com/doc/refman/8.0/en/sql-prepared-statements.html
+		var (
+			preparedStmtTx   *PreparedStmtTX
+			isPreparedStmtTx bool
+		)
+		// close prepared statement, because SavePoint not support prepared statement.
+		if preparedStmtTx, isPreparedStmtTx = db.Statement.ConnPool.(*PreparedStmtTX); isPreparedStmtTx {
+			db.Statement.ConnPool = preparedStmtTx.Tx
+		}
 		db.AddError(savePointer.RollbackTo(db, name))
+		// restore prepared statement
+		if isPreparedStmtTx {
+			db.Statement.ConnPool = preparedStmtTx
+		}
 	} else {
 		db.AddError(ErrUnsupportedDriver)
 	}
 	return db
 }
 
-// Exec execute raw sql
+// Exec executes raw sql
 func (db *DB) Exec(sql string, values ...interface{}) (tx *DB) {
 	tx = db.getInstance()
 	tx.Statement.SQL = strings.Builder{}
@@ -642,6 +776,5 @@ func (db *DB) Exec(sql string, values ...interface{}) (tx *DB) {
 		clause.Expr{SQL: sql, Vars: values}.Build(tx.Statement)
 	}
 
-	tx.callbacks.Raw().Execute(tx)
-	return
+	return tx.callbacks.Raw().Execute(tx)
 }

generics.go

@@ -0,0 +1,605 @@
+package gorm
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"sort"
+	"strings"
+
+	"gorm.io/gorm/clause"
+	"gorm.io/gorm/logger"
+)
+
+type result struct {
+	Result       sql.Result
+	RowsAffected int64
+}
+
+func (info *result) ModifyStatement(stmt *Statement) {
+	stmt.Result = info
+}
+
+// Build implements clause.Expression interface
+func (result) Build(clause.Builder) {
+}
+
+func WithResult() *result {
+	return &result{}
+}
+
+type Interface[T any] interface {
+	Raw(sql string, values ...interface{}) ExecInterface[T]
+	Exec(ctx context.Context, sql string, values ...interface{}) error
+	CreateInterface[T]
+}
+
+type CreateInterface[T any] interface {
+	ChainInterface[T]
+	Table(name string, args ...interface{}) CreateInterface[T]
+	Create(ctx context.Context, r *T) error
+	CreateInBatches(ctx context.Context, r *[]T, batchSize int) error
+}
+
+type ChainInterface[T any] interface {
+	ExecInterface[T]
+	Scopes(scopes ...func(db *Statement)) ChainInterface[T]
+	Where(query interface{}, args ...interface{}) ChainInterface[T]
+	Not(query interface{}, args ...interface{}) ChainInterface[T]
+	Or(query interface{}, args ...interface{}) ChainInterface[T]
+	Limit(offset int) ChainInterface[T]
+	Offset(offset int) ChainInterface[T]
+	Joins(query clause.JoinTarget, on func(db JoinBuilder, joinTable clause.Table, curTable clause.Table) error) ChainInterface[T]
+	Preload(association string, query func(db PreloadBuilder) error) ChainInterface[T]
+	Select(query string, args ...interface{}) ChainInterface[T]
+	Omit(columns ...string) ChainInterface[T]
+	MapColumns(m map[string]string) ChainInterface[T]
+	Distinct(args ...interface{}) ChainInterface[T]
+	Group(name string) ChainInterface[T]
+	Having(query interface{}, args ...interface{}) ChainInterface[T]
+	Order(value interface{}) ChainInterface[T]
+
+	Build(builder clause.Builder)
+
+	Delete(ctx context.Context) (rowsAffected int, err error)
+	Update(ctx context.Context, name string, value any) (rowsAffected int, err error)
+	Updates(ctx context.Context, t T) (rowsAffected int, err error)
+	Count(ctx context.Context, column string) (result int64, err error)
+}
+
+type ExecInterface[T any] interface {
+	Scan(ctx context.Context, r interface{}) error
+	First(context.Context) (T, error)
+	Last(ctx context.Context) (T, error)
+	Take(context.Context) (T, error)
+	Find(ctx context.Context) ([]T, error)
+	FindInBatches(ctx context.Context, batchSize int, fc func(data []T, batch int) error) error
+	Row(ctx context.Context) *sql.Row
+	Rows(ctx context.Context) (*sql.Rows, error)
+}
+
+type JoinBuilder interface {
+	Select(...string) JoinBuilder
+	Omit(...string) JoinBuilder
+	Where(query interface{}, args ...interface{}) JoinBuilder
+	Not(query interface{}, args ...interface{}) JoinBuilder
+	Or(query interface{}, args ...interface{}) JoinBuilder
+}
+
+type PreloadBuilder interface {
+	Select(...string) PreloadBuilder
+	Omit(...string) PreloadBuilder
+	Where(query interface{}, args ...interface{}) PreloadBuilder
+	Not(query interface{}, args ...interface{}) PreloadBuilder
+	Or(query interface{}, args ...interface{}) PreloadBuilder
+	Limit(offset int) PreloadBuilder
+	Offset(offset int) PreloadBuilder
+	Order(value interface{}) PreloadBuilder
+	LimitPerRecord(num int) PreloadBuilder
+}
+
+type op func(*DB) *DB
+
+func G[T any](db *DB, opts ...clause.Expression) Interface[T] {
+	v := &g[T]{
+		db:  db,
+		ops: make([]op, 0, 5),
+	}
+
+	if len(opts) > 0 {
+		v.ops = append(v.ops, func(db *DB) *DB {
+			return db.Clauses(opts...)
+		})
+	}
+
+	v.createG = &createG[T]{
+		chainG: chainG[T]{
+			execG: execG[T]{g: v},
+		},
+	}
+	return v
+}
+
+type g[T any] struct {
+	*createG[T]
+	db  *DB
+	ops []op
+}
+
+func (g *g[T]) apply(ctx context.Context) *DB {
+	db := g.db
+	if !db.DryRun {
+		db = db.Session(&Session{NewDB: true, Context: ctx}).getInstance()
+	}
+
+	for _, op := range g.ops {
+		db = op(db)
+	}
+	return db
+}
+
+func (c *g[T]) Raw(sql string, values ...interface{}) ExecInterface[T] {
+	return execG[T]{g: &g[T]{
+		db: c.db,
+		ops: append(c.ops, func(db *DB) *DB {
+			return db.Raw(sql, values...)
+		}),
+	}}
+}
+
+func (c *g[T]) Exec(ctx context.Context, sql string, values ...interface{}) error {
+	return c.apply(ctx).Exec(sql, values...).Error
+}
+
+type createG[T any] struct {
+	chainG[T]
+}
+
+func (c createG[T]) Table(name string, args ...interface{}) CreateInterface[T] {
+	return createG[T]{c.with(func(db *DB) *DB {
+		return db.Table(name, args...)
+	})}
+}
+
+func (c createG[T]) Create(ctx context.Context, r *T) error {
+	return c.g.apply(ctx).Create(r).Error
+}
+
+func (c createG[T]) CreateInBatches(ctx context.Context, r *[]T, batchSize int) error {
+	return c.g.apply(ctx).CreateInBatches(r, batchSize).Error
+}
+
+type chainG[T any] struct {
+	execG[T]
+}
+
+func (c chainG[T]) getInstance() *DB {
+	var r T
+	return c.g.apply(context.Background()).Model(r).getInstance()
+}
+
+func (c chainG[T]) with(v op) chainG[T] {
+	return chainG[T]{
+		execG: execG[T]{g: &g[T]{
+			db:  c.g.db,
+			ops: append(append([]op(nil), c.g.ops...), v),
+		}},
+	}
+}
+
+func (c chainG[T]) Scopes(scopes ...func(db *Statement)) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		for _, fc := range scopes {
+			fc(db.Statement)
+		}
+		return db
+	})
+}
+
+func (c chainG[T]) Table(name string, args ...interface{}) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Table(name, args...)
+	})
+}
+
+func (c chainG[T]) Where(query interface{}, args ...interface{}) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Where(query, args...)
+	})
+}
+
+func (c chainG[T]) Not(query interface{}, args ...interface{}) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Not(query, args...)
+	})
+}
+
+func (c chainG[T]) Or(query interface{}, args ...interface{}) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Or(query, args...)
+	})
+}
+
+func (c chainG[T]) Limit(offset int) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Limit(offset)
+	})
+}
+
+func (c chainG[T]) Offset(offset int) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Offset(offset)
+	})
+}
+
+type joinBuilder struct {
+	db *DB
+}
+
+func (q *joinBuilder) Where(query interface{}, args ...interface{}) JoinBuilder {
+	q.db.Where(query, args...)
+	return q
+}
+
+func (q *joinBuilder) Or(query interface{}, args ...interface{}) JoinBuilder {
+	q.db.Where(query, args...)
+	return q
+}
+
+func (q *joinBuilder) Not(query interface{}, args ...interface{}) JoinBuilder {
+	q.db.Where(query, args...)
+	return q
+}
+
+func (q *joinBuilder) Select(columns ...string) JoinBuilder {
+	q.db.Select(columns)
+	return q
+}
+
+func (q *joinBuilder) Omit(columns ...string) JoinBuilder {
+	q.db.Omit(columns...)
+	return q
+}
+
+type preloadBuilder struct {
+	limitPerRecord int
+	db             *DB
+}
+
+func (q *preloadBuilder) Where(query interface{}, args ...interface{}) PreloadBuilder {
+	q.db.Where(query, args...)
+	return q
+}
+
+func (q *preloadBuilder) Or(query interface{}, args ...interface{}) PreloadBuilder {
+	q.db.Where(query, args...)
+	return q
+}
+
+func (q *preloadBuilder) Not(query interface{}, args ...interface{}) PreloadBuilder {
+	q.db.Where(query, args...)
+	return q
+}
+
+func (q *preloadBuilder) Select(columns ...string) PreloadBuilder {
+	q.db.Select(columns)
+	return q
+}
+
+func (q *preloadBuilder) Omit(columns ...string) PreloadBuilder {
+	q.db.Omit(columns...)
+	return q
+}
+
+func (q *preloadBuilder) Limit(limit int) PreloadBuilder {
+	q.db.Limit(limit)
+	return q
+}
+
+func (q *preloadBuilder) Offset(offset int) PreloadBuilder {
+	q.db.Offset(offset)
+	return q
+}
+
+func (q *preloadBuilder) Order(value interface{}) PreloadBuilder {
+	q.db.Order(value)
+	return q
+}
+
+func (q *preloadBuilder) LimitPerRecord(num int) PreloadBuilder {
+	q.limitPerRecord = num
+	return q
+}
+
+func (c chainG[T]) Joins(jt clause.JoinTarget, on func(db JoinBuilder, joinTable clause.Table, curTable clause.Table) error) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		if jt.Table == "" {
+			jt.Table = clause.JoinTable(strings.Split(jt.Association, ".")...).Name
+		}
+
+		q := joinBuilder{db: db.Session(&Session{NewDB: true, Initialized: true}).Table(jt.Table)}
+		if on != nil {
+			if err := on(&q, clause.Table{Name: jt.Table}, clause.Table{Name: clause.CurrentTable}); err != nil {
+				db.AddError(err)
+			}
+		}
+
+		j := join{
+			Name:     jt.Association,
+			Alias:    jt.Table,
+			Selects:  q.db.Statement.Selects,
+			Omits:    q.db.Statement.Omits,
+			JoinType: jt.Type,
+		}
+
+		if where, ok := q.db.Statement.Clauses["WHERE"].Expression.(clause.Where); ok {
+			j.On = &where
+		}
+
+		if jt.Subquery != nil {
+			joinType := j.JoinType
+			if joinType == "" {
+				joinType = clause.LeftJoin
+			}
+
+			if db, ok := jt.Subquery.(interface{ getInstance() *DB }); ok {
+				stmt := db.getInstance().Statement
+				if len(j.Selects) == 0 {
+					j.Selects = stmt.Selects
+				}
+				if len(j.Omits) == 0 {
+					j.Omits = stmt.Omits
+				}
+			}
+
+			expr := clause.NamedExpr{SQL: fmt.Sprintf("%s JOIN (?) AS ?", joinType), Vars: []interface{}{jt.Subquery, clause.Table{Name: j.Alias}}}
+
+			if j.On != nil {
+				expr.SQL += " ON ?"
+				expr.Vars = append(expr.Vars, clause.AndConditions{Exprs: j.On.Exprs})
+			}
+
+			j.Expression = expr
+		}
+
+		db.Statement.Joins = append(db.Statement.Joins, j)
+		sort.Slice(db.Statement.Joins, func(i, j int) bool {
+			return db.Statement.Joins[i].Name < db.Statement.Joins[j].Name
+		})
+		return db
+	})
+}
+
+func (c chainG[T]) Select(query string, args ...interface{}) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Select(query, args...)
+	})
+}
+
+func (c chainG[T]) Omit(columns ...string) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Omit(columns...)
+	})
+}
+
+func (c chainG[T]) MapColumns(m map[string]string) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.MapColumns(m)
+	})
+}
+
+func (c chainG[T]) Distinct(args ...interface{}) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Distinct(args...)
+	})
+}
+
+func (c chainG[T]) Group(name string) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Group(name)
+	})
+}
+
+func (c chainG[T]) Having(query interface{}, args ...interface{}) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Having(query, args...)
+	})
+}
+
+func (c chainG[T]) Order(value interface{}) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Order(value)
+	})
+}
+
+func (c chainG[T]) Preload(association string, query func(db PreloadBuilder) error) ChainInterface[T] {
+	return c.with(func(db *DB) *DB {
+		return db.Preload(association, func(tx *DB) *DB {
+			q := preloadBuilder{db: tx.getInstance()}
+			if query != nil {
+				if err := query(&q); err != nil {
+					db.AddError(err)
+				}
+			}
+
+			relation, ok := db.Statement.Schema.Relationships.Relations[association]
+			if !ok {
+				if preloadFields := strings.Split(association, "."); len(preloadFields) > 1 {
+					relationships := db.Statement.Schema.Relationships
+					for _, field := range preloadFields {
+						var ok bool
+						relation, ok = relationships.Relations[field]
+						if ok {
+							relationships = relation.FieldSchema.Relationships
+						} else {
+							db.AddError(fmt.Errorf("relation %s not found", association))
+							return nil
+						}
+					}
+				} else {
+					db.AddError(fmt.Errorf("relation %s not found", association))
+					return nil
+				}
+			}
+
+			if q.limitPerRecord > 0 {
+				if relation.JoinTable != nil {
+					tx.AddError(fmt.Errorf("many2many relation %s don't support LimitPerRecord", association))
+					return tx
+				}
+
+				refColumns := []clause.Column{}
+				for _, rel := range relation.References {
+					if rel.OwnPrimaryKey {
+						refColumns = append(refColumns, clause.Column{Name: rel.ForeignKey.DBName})
+					}
+				}
+
+				if len(refColumns) != 0 {
+					selectExpr := clause.CommaExpression{}
+					for _, column := range q.db.Statement.Selects {
+						selectExpr.Exprs = append(selectExpr.Exprs, clause.Expr{SQL: "?", Vars: []interface{}{clause.Column{Name: column}}})
+					}
+
+					if len(selectExpr.Exprs) == 0 {
+						selectExpr.Exprs = []clause.Expression{clause.Expr{SQL: "*", Vars: []interface{}{}}}
+					}
+
+					partitionBy := clause.CommaExpression{}
+					for _, column := range refColumns {
+						partitionBy.Exprs = append(partitionBy.Exprs, clause.Expr{SQL: "?", Vars: []interface{}{clause.Column{Name: column.Name}}})
+					}
+
+					rnnColumn := clause.Column{Name: "gorm_preload_rnn"}
+					sql := "ROW_NUMBER() OVER (PARTITION BY ? ?)"
+					vars := []interface{}{partitionBy}
+					if orderBy, ok := q.db.Statement.Clauses["ORDER BY"]; ok {
+						vars = append(vars, orderBy)
+					} else {
+						vars = append(vars, clause.Clause{Name: "ORDER BY", Expression: clause.OrderBy{
+							Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}},
+						}})
+					}
+					vars = append(vars, rnnColumn)
+
+					selectExpr.Exprs = append(selectExpr.Exprs, clause.Expr{SQL: sql + " AS ?", Vars: vars})
+
+					q.db.Clauses(clause.Select{Expression: selectExpr})
+
+					return q.db.Session(&Session{NewDB: true}).Unscoped().Table("(?) t", q.db).Where("? <= ?", rnnColumn, q.limitPerRecord)
+				}
+			}
+
+			return q.db
+		})
+	})
+}
+
+func (c chainG[T]) Delete(ctx context.Context) (rowsAffected int, err error) {
+	r := new(T)
+	res := c.g.apply(ctx).Delete(r)
+	return int(res.RowsAffected), res.Error
+}
+
+func (c chainG[T]) Update(ctx context.Context, name string, value any) (rowsAffected int, err error) {
+	var r T
+	res := c.g.apply(ctx).Model(r).Update(name, value)
+	return int(res.RowsAffected), res.Error
+}
+
+func (c chainG[T]) Updates(ctx context.Context, t T) (rowsAffected int, err error) {
+	res := c.g.apply(ctx).Updates(t)
+	return int(res.RowsAffected), res.Error
+}
+
+func (c chainG[T]) Count(ctx context.Context, column string) (result int64, err error) {
+	var r T
+	err = c.g.apply(ctx).Model(r).Select(column).Count(&result).Error
+	return
+}
+
+func (c chainG[T]) Build(builder clause.Builder) {
+	subdb := c.getInstance()
+	subdb.Logger = logger.Discard
+	subdb.DryRun = true
+
+	if stmt, ok := builder.(*Statement); ok {
+		if subdb.Statement.SQL.Len() > 0 {
+			var (
+				vars = subdb.Statement.Vars
+				sql  = subdb.Statement.SQL.String()
+			)
+
+			subdb.Statement.Vars = make([]interface{}, 0, len(vars))
+			for _, vv := range vars {
+				subdb.Statement.Vars = append(subdb.Statement.Vars, vv)
+				bindvar := strings.Builder{}
+				subdb.BindVarTo(&bindvar, subdb.Statement, vv)
+				sql = strings.Replace(sql, bindvar.String(), "?", 1)
+			}
+
+			subdb.Statement.SQL.Reset()
+			subdb.Statement.Vars = stmt.Vars
+			if strings.Contains(sql, "@") {
+				clause.NamedExpr{SQL: sql, Vars: vars}.Build(subdb.Statement)
+			} else {
+				clause.Expr{SQL: sql, Vars: vars}.Build(subdb.Statement)
+			}
+		} else {
+			subdb.Statement.Vars = append(stmt.Vars, subdb.Statement.Vars...)
+			subdb.callbacks.Query().Execute(subdb)
+		}
+
+		builder.WriteString(subdb.Statement.SQL.String())
+		stmt.Vars = subdb.Statement.Vars
+	}
+}
+
+type execG[T any] struct {
+	g *g[T]
+}
+
+func (g execG[T]) First(ctx context.Context) (T, error) {
+	var r T
+	err := g.g.apply(ctx).First(&r).Error
+	return r, err
+}
+
+func (g execG[T]) Scan(ctx context.Context, result interface{}) error {
+	var r T
+	err := g.g.apply(ctx).Model(r).Find(result).Error
+	return err
+}
+
+func (g execG[T]) Last(ctx context.Context) (T, error) {
+	var r T
+	err := g.g.apply(ctx).Last(&r).Error
+	return r, err
+}
+
+func (g execG[T]) Take(ctx context.Context) (T, error) {
+	var r T
+	err := g.g.apply(ctx).Take(&r).Error
+	return r, err
+}
+
+func (g execG[T]) Find(ctx context.Context) ([]T, error) {
+	var r []T
+	err := g.g.apply(ctx).Find(&r).Error
+	return r, err
+}
+
+func (g execG[T]) FindInBatches(ctx context.Context, batchSize int, fc func(data []T, batch int) error) error {
+	var data []T
+	return g.g.apply(ctx).FindInBatches(&data, batchSize, func(tx *DB, batch int) error {
+		return fc(data, batch)
+	}).Error
+}
+
+func (g execG[T]) Row(ctx context.Context) *sql.Row {
+	return g.g.apply(ctx).Row()
+}
+
+func (g execG[T]) Rows(ctx context.Context) (*sql.Rows, error) {
+	return g.g.apply(ctx).Rows()
+}

go.mod

@@ -1,8 +1,9 @@
 module gorm.io/gorm
 
-go 1.14
+go 1.18
 
 require (
 	github.com/jinzhu/inflection v1.0.0
-	github.com/jinzhu/now v1.1.1
+	github.com/jinzhu/now v1.1.5
+	golang.org/x/text v0.20.0
 )

go.sum

@@ -1,4 +1,6 @@
 github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD/E=
 github.com/jinzhu/inflection v1.0.0/go.mod h1:h+uFLlag+Qp1Va5pdKtLDYj+kHp5pxUVkryuEj+Srlc=
-github.com/jinzhu/now v1.1.1 h1:g39TucaRWyV3dwDO++eEc6qf8TVIQ/Da48WmqjZ3i7E=
-github.com/jinzhu/now v1.1.1/go.mod h1:d3SSVoowX0Lcu0IBviAWJpolVfI5UJVZZ7cO71lE/z8=
+github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=
+github.com/jinzhu/now v1.1.5/go.mod h1:d3SSVoowX0Lcu0IBviAWJpolVfI5UJVZZ7cO71lE/z8=
+golang.org/x/text v0.20.0 h1:gK/Kv2otX8gz+wn7Rmb3vT96ZwuoxnQlY+HlJVj7Qug=
+golang.org/x/text v0.20.0/go.mod h1:D4IsuqiFMhST5bX19pQ9ikHC2GsaKyk/oF+pn3ducp4=

gorm.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"reflect"
+	"sort"
 	"sync"
 	"time"
 
@@ -19,7 +21,9 @@ const preparedStmtDBKey = "preparedStmt"
 type Config struct {
 	// GORM perform single create, update, delete operations in transactions by default to ensure database data integrity
 	// You can disable it by setting `SkipDefaultTransaction` to true
-	SkipDefaultTransaction bool
+	SkipDefaultTransaction    bool
+	DefaultTransactionTimeout time.Duration
+
 	// NamingStrategy tables, columns naming strategy
 	NamingStrategy schema.Namer
 	// FullSaveAssociations full save associations
@@ -32,10 +36,17 @@ type Config struct {
 	DryRun bool
 	// PrepareStmt executes the given query in cached statement
 	PrepareStmt bool
+	// PrepareStmt cache support LRU expired,
+	// default maxsize=int64 Max value and ttl=1h
+	PrepareStmtMaxSize int
+	PrepareStmtTTL     time.Duration
+
 	// DisableAutomaticPing
 	DisableAutomaticPing bool
 	// DisableForeignKeyConstraintWhenMigrating
 	DisableForeignKeyConstraintWhenMigrating bool
+	// IgnoreRelationshipsWhenMigrating
+	IgnoreRelationshipsWhenMigrating bool
 	// DisableNestedTransaction disable nested transaction
 	DisableNestedTransaction bool
 	// AllowGlobalUpdate allow global update
@@ -44,6 +55,10 @@ type Config struct {
 	QueryFields bool
 	// CreateBatchSize default create batch size
 	CreateBatchSize int
+	// TranslateError enabling error translation
+	TranslateError bool
+	// PropagateUnscoped propagate Unscoped to every other nested statement
+	PropagateUnscoped bool
 
 	// ClauseBuilders clause builder
 	ClauseBuilders map[string]clause.ClauseBuilder
@@ -58,6 +73,7 @@ type Config struct {
 	cacheStore *sync.Map
 }
 
+// Apply update config to new config
 func (c *Config) Apply(config *Config) error {
 	if config != c {
 		*config = *c
@@ -65,6 +81,7 @@ func (c *Config) Apply(config *Config) error {
 	return nil
 }
 
+// AfterInitialize initialize plugins after db connected
 func (c *Config) AfterInitialize(db *DB) error {
 	if db != nil {
 		for _, plugin := range c.Plugins {
@@ -76,6 +93,7 @@ func (c *Config) AfterInitialize(db *DB) error {
 	return nil
 }
 
+// Option gorm option interface
 type Option interface {
 	Apply(*Config) error
 	AfterInitialize(*DB) error
@@ -95,11 +113,13 @@ type Session struct {
 	DryRun                   bool
 	PrepareStmt              bool
 	NewDB                    bool
+	Initialized              bool
 	SkipHooks                bool
 	SkipDefaultTransaction   bool
 	DisableNestedTransaction bool
 	AllowGlobalUpdate        bool
 	FullSaveAssociations     bool
+	PropagateUnscoped        bool
 	QueryFields              bool
 	Context                  context.Context
 	Logger                   logger.Interface
@@ -111,14 +131,34 @@ type Session struct {
 func Open(dialector Dialector, opts ...Option) (db *DB, err error) {
 	config := &Config{}
 
+	sort.Slice(opts, func(i, j int) bool {
+		_, isConfig := opts[i].(*Config)
+		_, isConfig2 := opts[j].(*Config)
+		return isConfig && !isConfig2
+	})
+
+	if len(opts) > 0 {
+		if c, ok := opts[0].(*Config); ok {
+			config = c
+		} else {
+			opts = append([]Option{config}, opts...)
+		}
+	}
+
+	var skipAfterInitialize bool
 	for _, opt := range opts {
 		if opt != nil {
-			if err := opt.Apply(config); err != nil {
-				return nil, err
+			if applyErr := opt.Apply(config); applyErr != nil {
+				return nil, applyErr
 			}
-			defer func() {
-				opt.AfterInitialize(db)
-			}()
+			defer func(opt Option) {
+				if skipAfterInitialize {
+					return
+				}
+				if errr := opt.AfterInitialize(db); errr != nil {
+					err = errr
+				}
+			}(opt)
 		}
 	}
 
@@ -129,7 +169,7 @@ func Open(dialector Dialector, opts ...Option) (db *DB, err error) {
 	}
 
 	if config.NamingStrategy == nil {
-		config.NamingStrategy = schema.NamingStrategy{}
+		config.NamingStrategy = schema.NamingStrategy{IdentifierMaxLength: 64} // Default Identifier length is 64
 	}
 
 	if config.Logger == nil {
@@ -162,17 +202,26 @@ func Open(dialector Dialector, opts ...Option) (db *DB, err error) {
 
 	if config.Dialector != nil {
 		err = config.Dialector.Initialize(db)
-	}
+		if err != nil {
+			if db, _ := db.DB(); db != nil {
+				_ = db.Close()
+			}
 
-	preparedStmt := &PreparedStmtDB{
-		ConnPool:    db.ConnPool,
-		Stmts:       map[string]Stmt{},
-		Mux:         &sync.RWMutex{},
-		PreparedSQL: make([]string, 0, 100),
+			// DB is not initialized, so we skip AfterInitialize
+			skipAfterInitialize = true
+			return
+		}
+
+		if config.TranslateError {
+			if _, ok := db.Dialector.(ErrorTranslator); !ok {
+				config.Logger.Warn(context.Background(), "The TranslateError option is enabled, but the Dialector %s does not implement ErrorTranslator.", db.Dialector.Name())
+			}
+		}
 	}
-	db.cacheStore.Store(preparedStmtDBKey, preparedStmt)
 
 	if config.PrepareStmt {
+		preparedStmt := NewPreparedStmtDB(db.ConnPool, config.PrepareStmtMaxSize, config.PrepareStmtTTL)
+		db.cacheStore.Store(preparedStmtDBKey, preparedStmt)
 		db.ConnPool = preparedStmt
 	}
 
@@ -223,6 +272,10 @@ func (db *DB) Session(config *Session) *DB {
 		txConfig.FullSaveAssociations = true
 	}
 
+	if config.PropagateUnscoped {
+		txConfig.PropagateUnscoped = true
+	}
+
 	if config.Context != nil || config.PrepareStmt || config.SkipHooks {
 		tx.Statement = tx.Statement.clone()
 		tx.Statement.DB = tx
@@ -233,16 +286,30 @@ func (db *DB) Session(config *Session) *DB {
 	}
 
 	if config.PrepareStmt {
+		var preparedStmt *PreparedStmtDB
+
 		if v, ok := db.cacheStore.Load(preparedStmtDBKey); ok {
-			preparedStmt := v.(*PreparedStmtDB)
+			preparedStmt = v.(*PreparedStmtDB)
+		} else {
+			preparedStmt = NewPreparedStmtDB(db.ConnPool, db.PrepareStmtMaxSize, db.PrepareStmtTTL)
+			db.cacheStore.Store(preparedStmtDBKey, preparedStmt)
+		}
+
+		switch t := tx.Statement.ConnPool.(type) {
+		case Tx:
+			tx.Statement.ConnPool = &PreparedStmtTX{
+				Tx:             t,
+				PreparedStmtDB: preparedStmt,
+			}
+		default:
 			tx.Statement.ConnPool = &PreparedStmtDB{
 				ConnPool: db.Config.ConnPool,
 				Mux:      preparedStmt.Mux,
 				Stmts:    preparedStmt.Stmts,
 			}
-			txConfig.ConnPool = tx.Statement.ConnPool
-			txConfig.PrepareStmt = true
 		}
+		txConfig.ConnPool = tx.Statement.ConnPool
+		txConfig.PrepareStmt = true
 	}
 
 	if config.SkipHooks {
@@ -273,6 +340,10 @@ func (db *DB) Session(config *Session) *DB {
 		tx.Config.NowFunc = config.NowFunc
 	}
 
+	if config.Initialized {
+		tx = tx.getInstance()
+	}
+
 	return tx
 }
 
@@ -283,7 +354,8 @@ func (db *DB) WithContext(ctx context.Context) *DB {
 
 // Debug start debug mode
 func (db *DB) Debug() (tx *DB) {
-	return db.Session(&Session{
+	tx = db.getInstance()
+	return tx.Session(&Session{
 		Logger: db.Logger.LogMode(logger.Info),
 	})
 }
@@ -319,10 +391,18 @@ func (db *DB) Callback() *callbacks {
 
 // AddError add error to db
 func (db *DB) AddError(err error) error {
-	if db.Error == nil {
-		db.Error = err
-	} else if err != nil {
-		db.Error = fmt.Errorf("%v; %w", db.Error, err)
+	if err != nil {
+		if db.Config.TranslateError {
+			if errTranslator, ok := db.Dialector.(ErrorTranslator); ok {
+				err = errTranslator.Translate(err)
+			}
+		}
+
+		if db.Error == nil {
+			db.Error = err
+		} else {
+			db.Error = fmt.Errorf("%v; %w", db.Error, err)
+		}
 	}
 	return db.Error
 }
@@ -330,30 +410,42 @@ func (db *DB) AddError(err error) error {
 // DB returns `*sql.DB`
 func (db *DB) DB() (*sql.DB, error) {
 	connPool := db.ConnPool
-
-	if stmtDB, ok := connPool.(*PreparedStmtDB); ok {
-		connPool = stmtDB.ConnPool
+	if db.Statement != nil && db.Statement.ConnPool != nil {
+		connPool = db.Statement.ConnPool
+	}
+	if tx, ok := connPool.(*sql.Tx); ok && tx != nil {
+		return (*sql.DB)(reflect.ValueOf(tx).Elem().FieldByName("db").UnsafePointer()), nil
 	}
 
-	if sqldb, ok := connPool.(*sql.DB); ok {
+	if dbConnector, ok := connPool.(GetDBConnector); ok && dbConnector != nil {
+		if sqldb, err := dbConnector.GetDBConn(); sqldb != nil || err != nil {
+			return sqldb, err
+		}
+	}
+
+	if sqldb, ok := connPool.(*sql.DB); ok && sqldb != nil {
 		return sqldb, nil
 	}
 
-	return nil, ErrInvaildDB
+	return nil, ErrInvalidDB
 }
 
 func (db *DB) getInstance() *DB {
 	if db.clone > 0 {
-		tx := &DB{Config: db.Config}
+		tx := &DB{Config: db.Config, Error: db.Error}
 
 		if db.clone == 1 {
 			// clone with new statement
 			tx.Statement = &Statement{
-				DB:       tx,
-				ConnPool: db.Statement.ConnPool,
-				Context:  db.Statement.Context,
-				Clauses:  map[string]clause.Clause{},
-				Vars:     make([]interface{}, 0, 8),
+				DB:        tx,
+				ConnPool:  db.Statement.ConnPool,
+				Context:   db.Statement.Context,
+				Clauses:   map[string]clause.Clause{},
+				Vars:      make([]interface{}, 0, 8),
+				SkipHooks: db.Statement.SkipHooks,
+			}
+			if db.Config.PropagateUnscoped {
+				tx.Statement.Unscoped = db.Statement.Unscoped
 			}
 		} else {
 			// with clone statement
@@ -367,10 +459,12 @@ func (db *DB) getInstance() *DB {
 	return db
 }
 
+// Expr returns clause.Expr, which can be used to pass SQL expression as params
 func Expr(expr string, args ...interface{}) clause.Expr {
 	return clause.Expr{SQL: expr, Vars: args}
 }
 
+// SetupJoinTable setup join table schema
 func (db *DB) SetupJoinTable(model interface{}, field string, joinTable interface{}) error {
 	var (
 		tx                      = db.getInstance()
@@ -378,47 +472,50 @@ func (db *DB) SetupJoinTable(model interface{}, field string, joinTable interfac
 		modelSchema, joinSchema *schema.Schema
 	)
 
-	if err := stmt.Parse(model); err == nil {
-		modelSchema = stmt.Schema
-	} else {
+	err := stmt.Parse(model)
+	if err != nil {
 		return err
 	}
+	modelSchema = stmt.Schema
 
-	if err := stmt.Parse(joinTable); err == nil {
-		joinSchema = stmt.Schema
-	} else {
+	err = stmt.Parse(joinTable)
+	if err != nil {
 		return err
 	}
+	joinSchema = stmt.Schema
 
-	if relation, ok := modelSchema.Relationships.Relations[field]; ok && relation.JoinTable != nil {
-		for _, ref := range relation.References {
-			if f := joinSchema.LookUpField(ref.ForeignKey.DBName); f != nil {
-				f.DataType = ref.ForeignKey.DataType
-				f.GORMDataType = ref.ForeignKey.GORMDataType
-				if f.Size == 0 {
-					f.Size = ref.ForeignKey.Size
-				}
-				ref.ForeignKey = f
-			} else {
-				return fmt.Errorf("missing field %v for join table", ref.ForeignKey.DBName)
-			}
-		}
-
-		for name, rel := range relation.JoinTable.Relationships.Relations {
-			if _, ok := joinSchema.Relationships.Relations[name]; !ok {
-				rel.Schema = joinSchema
-				joinSchema.Relationships.Relations[name] = rel
-			}
-		}
-
-		relation.JoinTable = joinSchema
-	} else {
-		return fmt.Errorf("failed to found relation: %v", field)
+	relation, ok := modelSchema.Relationships.Relations[field]
+	isRelation := ok && relation.JoinTable != nil
+	if !isRelation {
+		return fmt.Errorf("failed to find relation: %s", field)
 	}
 
+	for _, ref := range relation.References {
+		f := joinSchema.LookUpField(ref.ForeignKey.DBName)
+		if f == nil {
+			return fmt.Errorf("missing field %s for join table", ref.ForeignKey.DBName)
+		}
+
+		f.DataType = ref.ForeignKey.DataType
+		f.GORMDataType = ref.ForeignKey.GORMDataType
+		if f.Size == 0 {
+			f.Size = ref.ForeignKey.Size
+		}
+		ref.ForeignKey = f
+	}
+
+	for name, rel := range relation.JoinTable.Relationships.Relations {
+		if _, ok := joinSchema.Relationships.Relations[name]; !ok {
+			rel.Schema = joinSchema
+			joinSchema.Relationships.Relations[name] = rel
+		}
+	}
+	relation.JoinTable = joinSchema
+
 	return nil
 }
 
+// Use use plugin
 func (db *DB) Use(plugin Plugin) error {
 	name := plugin.Name()
 	if _, ok := db.Plugins[name]; ok {
@@ -430,3 +527,18 @@ func (db *DB) Use(plugin Plugin) error {
 	db.Plugins[name] = plugin
 	return nil
 }
+
+// ToSQL for generate SQL string.
+//
+//	db.ToSQL(func(tx *gorm.DB) *gorm.DB {
+//			return tx.Model(&User{}).Where(&User{Name: "foo", Age: 20})
+//				.Limit(10).Offset(5)
+//				.Order("name ASC")
+//				.First(&User{})
+//	})
+func (db *DB) ToSQL(queryFn func(tx *DB) *DB) string {
+	tx := queryFn(db.Session(&Session{DryRun: true, SkipDefaultTransaction: true}).getInstance())
+	stmt := tx.Statement
+
+	return db.Dialector.Explain(stmt.SQL.String(), stmt.Vars...)
+}

interfaces.go

@@ -26,6 +26,10 @@ type Plugin interface {
 	Initialize(*DB) error
 }
 
+type ParamsFilter interface {
+	ParamsFilter(ctx context.Context, sql string, params ...interface{}) (string, []interface{})
+}
+
 // ConnPool db conns pool interface
 type ConnPool interface {
 	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
@@ -40,20 +44,49 @@ type SavePointerDialectorInterface interface {
 	RollbackTo(tx *DB, name string) error
 }
 
+// TxBeginner tx beginner
 type TxBeginner interface {
 	BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
 }
 
+// ConnPoolBeginner conn pool beginner
 type ConnPoolBeginner interface {
 	BeginTx(ctx context.Context, opts *sql.TxOptions) (ConnPool, error)
 }
 
+// TxCommitter tx committer
 type TxCommitter interface {
 	Commit() error
 	Rollback() error
 }
 
+// Tx sql.Tx interface
+type Tx interface {
+	ConnPool
+	TxCommitter
+	StmtContext(ctx context.Context, stmt *sql.Stmt) *sql.Stmt
+}
+
 // Valuer gorm valuer interface
 type Valuer interface {
 	GormValue(context.Context, *DB) clause.Expr
 }
+
+// GetDBConnector SQL db connector
+type GetDBConnector interface {
+	GetDBConn() (*sql.DB, error)
+}
+
+// Rows rows interface
+type Rows interface {
+	Columns() ([]string, error)
+	ColumnTypes() ([]*sql.ColumnType, error)
+	Next() bool
+	Scan(dest ...interface{}) error
+	Err() error
+	Close() error
+}
+
+type ErrorTranslator interface {
+	Translate(err error) error
+}

internal/lru/lru.go

@@ -0,0 +1,493 @@
+package lru
+
+// golang -lru
+// https://github.com/hashicorp/golang-lru
+import (
+	"sync"
+	"time"
+)
+
+// EvictCallback is used to get a callback when a cache entry is evicted
+type EvictCallback[K comparable, V any] func(key K, value V)
+
+// LRU implements a thread-safe LRU with expirable entries.
+type LRU[K comparable, V any] struct {
+	size      int
+	evictList *LruList[K, V]
+	items     map[K]*Entry[K, V]
+	onEvict   EvictCallback[K, V]
+
+	// expirable options
+	mu   sync.Mutex
+	ttl  time.Duration
+	done chan struct{}
+
+	// buckets for expiration
+	buckets []bucket[K, V]
+	// uint8 because it's number between 0 and numBuckets
+	nextCleanupBucket uint8
+}
+
+// bucket is a container for holding entries to be expired
+type bucket[K comparable, V any] struct {
+	entries     map[K]*Entry[K, V]
+	newestEntry time.Time
+}
+
+// noEvictionTTL - very long ttl to prevent eviction
+const noEvictionTTL = time.Hour * 24 * 365 * 10
+
+// because of uint8 usage for nextCleanupBucket, should not exceed 256.
+// casting it as uint8 explicitly requires type conversions in multiple places
+const numBuckets = 100
+
+// NewLRU returns a new thread-safe cache with expirable entries.
+//
+// Size parameter set to 0 makes cache of unlimited size, e.g. turns LRU mechanism off.
+//
+// Providing 0 TTL turns expiring off.
+//
+// Delete expired entries every 1/100th of ttl value. Goroutine which deletes expired entries runs indefinitely.
+func NewLRU[K comparable, V any](size int, onEvict EvictCallback[K, V], ttl time.Duration) *LRU[K, V] {
+	if size < 0 {
+		size = 0
+	}
+	if ttl <= 0 {
+		ttl = noEvictionTTL
+	}
+
+	res := LRU[K, V]{
+		ttl:       ttl,
+		size:      size,
+		evictList: NewList[K, V](),
+		items:     make(map[K]*Entry[K, V]),
+		onEvict:   onEvict,
+		done:      make(chan struct{}),
+	}
+
+	// initialize the buckets
+	res.buckets = make([]bucket[K, V], numBuckets)
+	for i := 0; i < numBuckets; i++ {
+		res.buckets[i] = bucket[K, V]{entries: make(map[K]*Entry[K, V])}
+	}
+
+	// enable deleteExpired() running in separate goroutine for cache with non-zero TTL
+	//
+	// Important: done channel is never closed, so deleteExpired() goroutine will never exit,
+	// it's decided to add functionality to close it in the version later than v2.
+	if res.ttl != noEvictionTTL {
+		go func(done <-chan struct{}) {
+			ticker := time.NewTicker(res.ttl / numBuckets)
+			defer ticker.Stop()
+			for {
+				select {
+				case <-done:
+					return
+				case <-ticker.C:
+					res.deleteExpired()
+				}
+			}
+		}(res.done)
+	}
+	return &res
+}
+
+// Purge clears the cache completely.
+// onEvict is called for each evicted key.
+func (c *LRU[K, V]) Purge() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	for k, v := range c.items {
+		if c.onEvict != nil {
+			c.onEvict(k, v.Value)
+		}
+		delete(c.items, k)
+	}
+	for _, b := range c.buckets {
+		for _, ent := range b.entries {
+			delete(b.entries, ent.Key)
+		}
+	}
+	c.evictList.Init()
+}
+
+// Add adds a value to the cache. Returns true if an eviction occurred.
+// Returns false if there was no eviction: the item was already in the cache,
+// or the size was not exceeded.
+func (c *LRU[K, V]) Add(key K, value V) (evicted bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	now := time.Now()
+
+	// Check for existing item
+	if ent, ok := c.items[key]; ok {
+		c.evictList.MoveToFront(ent)
+		c.removeFromBucket(ent) // remove the entry from its current bucket as expiresAt is renewed
+		ent.Value = value
+		ent.ExpiresAt = now.Add(c.ttl)
+		c.addToBucket(ent)
+		return false
+	}
+
+	// Add new item
+	ent := c.evictList.PushFrontExpirable(key, value, now.Add(c.ttl))
+	c.items[key] = ent
+	c.addToBucket(ent) // adds the entry to the appropriate bucket and sets entry.expireBucket
+
+	evict := c.size > 0 && c.evictList.Length() > c.size
+	// Verify size not exceeded
+	if evict {
+		c.removeOldest()
+	}
+	return evict
+}
+
+// Get looks up a key's value from the cache.
+func (c *LRU[K, V]) Get(key K) (value V, ok bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	var ent *Entry[K, V]
+	if ent, ok = c.items[key]; ok {
+		// Expired item check
+		if time.Now().After(ent.ExpiresAt) {
+			return value, false
+		}
+		c.evictList.MoveToFront(ent)
+		return ent.Value, true
+	}
+	return
+}
+
+// Contains checks if a key is in the cache, without updating the recent-ness
+// or deleting it for being stale.
+func (c *LRU[K, V]) Contains(key K) (ok bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	_, ok = c.items[key]
+	return ok
+}
+
+// Peek returns the key value (or undefined if not found) without updating
+// the "recently used"-ness of the key.
+func (c *LRU[K, V]) Peek(key K) (value V, ok bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	var ent *Entry[K, V]
+	if ent, ok = c.items[key]; ok {
+		// Expired item check
+		if time.Now().After(ent.ExpiresAt) {
+			return value, false
+		}
+		return ent.Value, true
+	}
+	return
+}
+
+// Remove removes the provided key from the cache, returning if the
+// key was contained.
+func (c *LRU[K, V]) Remove(key K) bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if ent, ok := c.items[key]; ok {
+		c.removeElement(ent)
+		return true
+	}
+	return false
+}
+
+// RemoveOldest removes the oldest item from the cache.
+func (c *LRU[K, V]) RemoveOldest() (key K, value V, ok bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if ent := c.evictList.Back(); ent != nil {
+		c.removeElement(ent)
+		return ent.Key, ent.Value, true
+	}
+	return
+}
+
+// GetOldest returns the oldest entry
+func (c *LRU[K, V]) GetOldest() (key K, value V, ok bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if ent := c.evictList.Back(); ent != nil {
+		return ent.Key, ent.Value, true
+	}
+	return
+}
+
+func (c *LRU[K, V]) KeyValues() map[K]V {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	maps := make(map[K]V)
+	now := time.Now()
+	for ent := c.evictList.Back(); ent != nil; ent = ent.PrevEntry() {
+		if now.After(ent.ExpiresAt) {
+			continue
+		}
+		maps[ent.Key] = ent.Value
+		// keys = append(keys, ent.Key)
+	}
+	return maps
+}
+
+// Keys returns a slice of the keys in the cache, from oldest to newest.
+// Expired entries are filtered out.
+func (c *LRU[K, V]) Keys() []K {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	keys := make([]K, 0, len(c.items))
+	now := time.Now()
+	for ent := c.evictList.Back(); ent != nil; ent = ent.PrevEntry() {
+		if now.After(ent.ExpiresAt) {
+			continue
+		}
+		keys = append(keys, ent.Key)
+	}
+	return keys
+}
+
+// Values returns a slice of the values in the cache, from oldest to newest.
+// Expired entries are filtered out.
+func (c *LRU[K, V]) Values() []V {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	values := make([]V, 0, len(c.items))
+	now := time.Now()
+	for ent := c.evictList.Back(); ent != nil; ent = ent.PrevEntry() {
+		if now.After(ent.ExpiresAt) {
+			continue
+		}
+		values = append(values, ent.Value)
+	}
+	return values
+}
+
+// Len returns the number of items in the cache.
+func (c *LRU[K, V]) Len() int {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return c.evictList.Length()
+}
+
+// Resize changes the cache size. Size of 0 means unlimited.
+func (c *LRU[K, V]) Resize(size int) (evicted int) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if size <= 0 {
+		c.size = 0
+		return 0
+	}
+	diff := c.evictList.Length() - size
+	if diff < 0 {
+		diff = 0
+	}
+	for i := 0; i < diff; i++ {
+		c.removeOldest()
+	}
+	c.size = size
+	return diff
+}
+
+// Close destroys cleanup goroutine. To clean up the cache, run Purge() before Close().
+// func (c *LRU[K, V]) Close() {
+//	c.mu.Lock()
+//	defer c.mu.Unlock()
+//	select {
+//	case <-c.done:
+//		return
+//	default:
+//	}
+//	close(c.done)
+// }
+
+// removeOldest removes the oldest item from the cache. Has to be called with lock!
+func (c *LRU[K, V]) removeOldest() {
+	if ent := c.evictList.Back(); ent != nil {
+		c.removeElement(ent)
+	}
+}
+
+// removeElement is used to remove a given list element from the cache. Has to be called with lock!
+func (c *LRU[K, V]) removeElement(e *Entry[K, V]) {
+	c.evictList.Remove(e)
+	delete(c.items, e.Key)
+	c.removeFromBucket(e)
+	if c.onEvict != nil {
+		c.onEvict(e.Key, e.Value)
+	}
+}
+
+// deleteExpired deletes expired records from the oldest bucket, waiting for the newest entry
+// in it to expire first.
+func (c *LRU[K, V]) deleteExpired() {
+	c.mu.Lock()
+	bucketIdx := c.nextCleanupBucket
+	timeToExpire := time.Until(c.buckets[bucketIdx].newestEntry)
+	// wait for newest entry to expire before cleanup without holding lock
+	if timeToExpire > 0 {
+		c.mu.Unlock()
+		time.Sleep(timeToExpire)
+		c.mu.Lock()
+	}
+	for _, ent := range c.buckets[bucketIdx].entries {
+		c.removeElement(ent)
+	}
+	c.nextCleanupBucket = (c.nextCleanupBucket + 1) % numBuckets
+	c.mu.Unlock()
+}
+
+// addToBucket adds entry to expire bucket so that it will be cleaned up when the time comes. Has to be called with lock!
+func (c *LRU[K, V]) addToBucket(e *Entry[K, V]) {
+	bucketID := (numBuckets + c.nextCleanupBucket - 1) % numBuckets
+	e.ExpireBucket = bucketID
+	c.buckets[bucketID].entries[e.Key] = e
+	if c.buckets[bucketID].newestEntry.Before(e.ExpiresAt) {
+		c.buckets[bucketID].newestEntry = e.ExpiresAt
+	}
+}
+
+// removeFromBucket removes the entry from its corresponding bucket. Has to be called with lock!
+func (c *LRU[K, V]) removeFromBucket(e *Entry[K, V]) {
+	delete(c.buckets[e.ExpireBucket].entries, e.Key)
+}
+
+// Cap returns the capacity of the cache
+func (c *LRU[K, V]) Cap() int {
+	return c.size
+}
+
+// Entry is an LRU Entry
+type Entry[K comparable, V any] struct {
+	// Next and previous pointers in the doubly-linked list of elements.
+	// To simplify the implementation, internally a list l is implemented
+	// as a ring, such that &l.root is both the next element of the last
+	// list element (l.Back()) and the previous element of the first list
+	// element (l.Front()).
+	next, prev *Entry[K, V]
+
+	// The list to which this element belongs.
+	list *LruList[K, V]
+
+	// The LRU Key of this element.
+	Key K
+
+	// The Value stored with this element.
+	Value V
+
+	// The time this element would be cleaned up, optional
+	ExpiresAt time.Time
+
+	// The expiry bucket item was put in, optional
+	ExpireBucket uint8
+}
+
+// PrevEntry returns the previous list element or nil.
+func (e *Entry[K, V]) PrevEntry() *Entry[K, V] {
+	if p := e.prev; e.list != nil && p != &e.list.root {
+		return p
+	}
+	return nil
+}
+
+// LruList represents a doubly linked list.
+// The zero Value for LruList is an empty list ready to use.
+type LruList[K comparable, V any] struct {
+	root Entry[K, V] // sentinel list element, only &root, root.prev, and root.next are used
+	len  int         // current list Length excluding (this) sentinel element
+}
+
+// Init initializes or clears list l.
+func (l *LruList[K, V]) Init() *LruList[K, V] {
+	l.root.next = &l.root
+	l.root.prev = &l.root
+	l.len = 0
+	return l
+}
+
+// NewList returns an initialized list.
+func NewList[K comparable, V any]() *LruList[K, V] { return new(LruList[K, V]).Init() }
+
+// Length returns the number of elements of list l.
+// The complexity is O(1).
+func (l *LruList[K, V]) Length() int { return l.len }
+
+// Back returns the last element of list l or nil if the list is empty.
+func (l *LruList[K, V]) Back() *Entry[K, V] {
+	if l.len == 0 {
+		return nil
+	}
+	return l.root.prev
+}
+
+// lazyInit lazily initializes a zero List Value.
+func (l *LruList[K, V]) lazyInit() {
+	if l.root.next == nil {
+		l.Init()
+	}
+}
+
+// insert inserts e after at, increments l.len, and returns e.
+func (l *LruList[K, V]) insert(e, at *Entry[K, V]) *Entry[K, V] {
+	e.prev = at
+	e.next = at.next
+	e.prev.next = e
+	e.next.prev = e
+	e.list = l
+	l.len++
+	return e
+}
+
+// insertValue is a convenience wrapper for insert(&Entry{Value: v, ExpiresAt: ExpiresAt}, at).
+func (l *LruList[K, V]) insertValue(k K, v V, expiresAt time.Time, at *Entry[K, V]) *Entry[K, V] {
+	return l.insert(&Entry[K, V]{Value: v, Key: k, ExpiresAt: expiresAt}, at)
+}
+
+// Remove removes e from its list, decrements l.len
+func (l *LruList[K, V]) Remove(e *Entry[K, V]) V {
+	e.prev.next = e.next
+	e.next.prev = e.prev
+	e.next = nil // avoid memory leaks
+	e.prev = nil // avoid memory leaks
+	e.list = nil
+	l.len--
+
+	return e.Value
+}
+
+// move moves e to next to at.
+func (l *LruList[K, V]) move(e, at *Entry[K, V]) {
+	if e == at {
+		return
+	}
+	e.prev.next = e.next
+	e.next.prev = e.prev
+
+	e.prev = at
+	e.next = at.next
+	e.prev.next = e
+	e.next.prev = e
+}
+
+// PushFront inserts a new element e with value v at the front of list l and returns e.
+func (l *LruList[K, V]) PushFront(k K, v V) *Entry[K, V] {
+	l.lazyInit()
+	return l.insertValue(k, v, time.Time{}, &l.root)
+}
+
+// PushFrontExpirable inserts a new expirable element e with Value v at the front of list l and returns e.
+func (l *LruList[K, V]) PushFrontExpirable(k K, v V, expiresAt time.Time) *Entry[K, V] {
+	l.lazyInit()
+	return l.insertValue(k, v, expiresAt, &l.root)
+}
+
+// MoveToFront moves element e to the front of list l.
+// If e is not an element of l, the list is not modified.
+// The element must not be nil.
+func (l *LruList[K, V]) MoveToFront(e *Entry[K, V]) {
+	if e.list != l || l.root.next == e {
+		return
+	}
+	// see comment in List.Remove about initialization of l
+	l.move(e, &l.root)
+}

internal/stmt_store/stmt_store.go

@@ -0,0 +1,183 @@
+package stmt_store
+
+import (
+	"context"
+	"database/sql"
+	"math"
+	"sync"
+	"time"
+
+	"gorm.io/gorm/internal/lru"
+)
+
+type Stmt struct {
+	*sql.Stmt
+	Transaction bool
+	prepared    chan struct{}
+	prepareErr  error
+}
+
+func (stmt *Stmt) Error() error {
+	return stmt.prepareErr
+}
+
+func (stmt *Stmt) Close() error {
+	<-stmt.prepared
+
+	if stmt.Stmt != nil {
+		return stmt.Stmt.Close()
+	}
+	return nil
+}
+
+// Store defines an interface for managing the caching operations of SQL statements (Stmt).
+// This interface provides methods for creating new statements, retrieving all cache keys,
+// getting cached statements, setting cached statements, and deleting cached statements.
+type Store interface {
+	// New creates a new Stmt object and caches it.
+	// Parameters:
+	//   ctx: The context for the request, which can carry deadlines, cancellation signals, etc.
+	//   key: The key representing the SQL query, used for caching and preparing the statement.
+	//   isTransaction: Indicates whether this operation is part of a transaction, which may affect the caching strategy.
+	//   connPool: A connection pool that provides database connections.
+	//   locker: A synchronization lock that is unlocked after initialization to avoid deadlocks.
+	// Returns:
+	//   *Stmt: A newly created statement object for executing SQL operations.
+	//   error: An error if the statement preparation fails.
+	New(ctx context.Context, key string, isTransaction bool, connPool ConnPool, locker sync.Locker) (*Stmt, error)
+
+	// Keys returns a slice of all cache keys in the store.
+	Keys() []string
+
+	// Get retrieves a Stmt object from the store based on the given key.
+	// Parameters:
+	//   key: The key used to look up the Stmt object.
+	// Returns:
+	//   *Stmt: The found Stmt object, or nil if not found.
+	//   bool: Indicates whether the corresponding Stmt object was successfully found.
+	Get(key string) (*Stmt, bool)
+
+	// Set stores the given Stmt object in the store and associates it with the specified key.
+	// Parameters:
+	//   key: The key used to associate the Stmt object.
+	//   value: The Stmt object to be stored.
+	Set(key string, value *Stmt)
+
+	// Delete removes the Stmt object corresponding to the specified key from the store.
+	// Parameters:
+	//   key: The key associated with the Stmt object to be deleted.
+	Delete(key string)
+}
+
+// defaultMaxSize defines the default maximum capacity of the cache.
+// Its value is the maximum value of the int64 type, which means that when the cache size is not specified,
+// the cache can theoretically store as many elements as possible.
+// (1 << 63) - 1 is the maximum value that an int64 type can represent.
+const (
+	defaultMaxSize = math.MaxInt
+	// defaultTTL defines the default time-to-live (TTL) for each cache entry.
+	// When the TTL for cache entries is not specified, each cache entry will expire after 24 hours.
+	defaultTTL = time.Hour * 24
+)
+
+// New creates and returns a new Store instance.
+//
+// Parameters:
+//   - size: The maximum capacity of the cache. If the provided size is less than or equal to 0,
+//     it defaults to defaultMaxSize.
+//   - ttl: The time-to-live duration for each cache entry. If the provided ttl is less than or equal to 0,
+//     it defaults to defaultTTL.
+//
+// This function defines an onEvicted callback that is invoked when a cache entry is evicted.
+// The callback ensures that if the evicted value (v) is not nil, its Close method is called asynchronously
+// to release associated resources.
+//
+// Returns:
+//   - A Store instance implemented by lruStore, which internally uses an LRU cache with the specified size,
+//     eviction callback, and TTL.
+func New(size int, ttl time.Duration) Store {
+	if size <= 0 {
+		size = defaultMaxSize
+	}
+
+	if ttl <= 0 {
+		ttl = defaultTTL
+	}
+
+	onEvicted := func(k string, v *Stmt) {
+		if v != nil {
+			go v.Close()
+		}
+	}
+	return &lruStore{lru: lru.NewLRU[string, *Stmt](size, onEvicted, ttl)}
+}
+
+type lruStore struct {
+	lru *lru.LRU[string, *Stmt]
+}
+
+func (s *lruStore) Keys() []string {
+	return s.lru.Keys()
+}
+
+func (s *lruStore) Get(key string) (*Stmt, bool) {
+	stmt, ok := s.lru.Get(key)
+	if ok && stmt != nil {
+		<-stmt.prepared
+	}
+	return stmt, ok
+}
+
+func (s *lruStore) Set(key string, value *Stmt) {
+	s.lru.Add(key, value)
+}
+
+func (s *lruStore) Delete(key string) {
+	s.lru.Remove(key)
+}
+
+type ConnPool interface {
+	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
+}
+
+// New creates a new Stmt object for executing SQL queries.
+// It caches the Stmt object for future use and handles preparation and error states.
+// Parameters:
+//
+//	ctx: Context for the request, used to carry deadlines, cancellation signals, etc.
+//	key: The key representing the SQL query, used for caching and preparing the statement.
+//	isTransaction: Indicates whether this operation is part of a transaction, affecting cache strategy.
+//	conn: A connection pool that provides database connections.
+//	locker: A synchronization lock that is unlocked after initialization to avoid deadlocks.
+//
+// Returns:
+//
+//	*Stmt: A newly created statement object for executing SQL operations.
+//	error: An error if the statement preparation fails.
+func (s *lruStore) New(ctx context.Context, key string, isTransaction bool, conn ConnPool, locker sync.Locker) (_ *Stmt, err error) {
+	// Create a Stmt object and set its Transaction property.
+	// The prepared channel is used to synchronize the statement preparation state.
+	cacheStmt := &Stmt{
+		Transaction: isTransaction,
+		prepared:    make(chan struct{}),
+	}
+	// Cache the Stmt object with the associated key.
+	s.Set(key, cacheStmt)
+	// Unlock after completing initialization to prevent deadlocks.
+	locker.Unlock()
+
+	// Ensure the prepared channel is closed after the function execution completes.
+	defer close(cacheStmt.prepared)
+
+	// Prepare the SQL statement using the provided connection.
+	cacheStmt.Stmt, err = conn.PrepareContext(ctx, key)
+	if err != nil {
+		// If statement preparation fails, record the error and remove the invalid Stmt object from the cache.
+		cacheStmt.prepareErr = err
+		s.Delete(key)
+		return &Stmt{}, err
+	}
+
+	// Return the successfully prepared Stmt object.
+	return cacheStmt, nil
+}

logger/logger.go

@@ -2,8 +2,9 @@ package logger
 
 import (
 	"context"
+	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"os"
 	"time"
@@ -11,6 +12,9 @@ import (
 	"gorm.io/gorm/utils"
 )
 
+// ErrRecordNotFound record not found error
+var ErrRecordNotFound = errors.New("record not found")
+
 // Colors
 const (
 	Reset       = "\033[0m"
@@ -27,13 +31,17 @@ const (
 	YellowBold  = "\033[33;1m"
 )
 
-// LogLevel
+// LogLevel log level
 type LogLevel int
 
 const (
+	// Silent silent log level
 	Silent LogLevel = iota + 1
+	// Error error log level
 	Error
+	// Warn warn log level
 	Warn
+	// Info info log level
 	Info
 )
 
@@ -42,10 +50,13 @@ type Writer interface {
 	Printf(string, ...interface{})
 }
 
+// Config logger config
 type Config struct {
-	SlowThreshold time.Duration
-	Colorful      bool
-	LogLevel      LogLevel
+	SlowThreshold             time.Duration
+	Colorful                  bool
+	IgnoreRecordNotFoundError bool
+	ParameterizedQueries      bool
+	LogLevel                  LogLevel
 }
 
 // Interface logger interface
@@ -54,19 +65,29 @@ type Interface interface {
 	Info(context.Context, string, ...interface{})
 	Warn(context.Context, string, ...interface{})
 	Error(context.Context, string, ...interface{})
-	Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error)
+	Trace(ctx context.Context, begin time.Time, fc func() (sql string, rowsAffected int64), err error)
 }
 
 var (
-	Discard = New(log.New(ioutil.Discard, "", log.LstdFlags), Config{})
+	// Discard logger will print any log to io.Discard
+	Discard = New(log.New(io.Discard, "", log.LstdFlags), Config{})
+	// Default Default logger
 	Default = New(log.New(os.Stdout, "\r\n", log.LstdFlags), Config{
-		SlowThreshold: 200 * time.Millisecond,
-		LogLevel:      Warn,
-		Colorful:      true,
+		SlowThreshold:             200 * time.Millisecond,
+		LogLevel:                  Warn,
+		IgnoreRecordNotFoundError: false,
+		Colorful:                  true,
 	})
+	// Recorder logger records running SQL into a recorder instance
 	Recorder = traceRecorder{Interface: Default, BeginAt: time.Now()}
+
+	// RecorderParamsFilter defaults to no-op, allows to be run-over by a different implementation
+	RecorderParamsFilter = func(ctx context.Context, sql string, params ...interface{}) (string, []interface{}) {
+		return sql, params
+	}
 )
 
+// New initialize logger
 func New(writer Writer, config Config) Interface {
 	var (
 		infoStr      = "%s\n[info] "
@@ -113,57 +134,69 @@ func (l *logger) LogMode(level LogLevel) Interface {
 }
 
 // Info print info
-func (l logger) Info(ctx context.Context, msg string, data ...interface{}) {
+func (l *logger) Info(ctx context.Context, msg string, data ...interface{}) {
 	if l.LogLevel >= Info {
 		l.Printf(l.infoStr+msg, append([]interface{}{utils.FileWithLineNum()}, data...)...)
 	}
 }
 
 // Warn print warn messages
-func (l logger) Warn(ctx context.Context, msg string, data ...interface{}) {
+func (l *logger) Warn(ctx context.Context, msg string, data ...interface{}) {
 	if l.LogLevel >= Warn {
 		l.Printf(l.warnStr+msg, append([]interface{}{utils.FileWithLineNum()}, data...)...)
 	}
 }
 
 // Error print error messages
-func (l logger) Error(ctx context.Context, msg string, data ...interface{}) {
+func (l *logger) Error(ctx context.Context, msg string, data ...interface{}) {
 	if l.LogLevel >= Error {
 		l.Printf(l.errStr+msg, append([]interface{}{utils.FileWithLineNum()}, data...)...)
 	}
 }
 
 // Trace print sql message
-func (l logger) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
-	if l.LogLevel > Silent {
-		elapsed := time.Since(begin)
-		switch {
-		case err != nil && l.LogLevel >= Error:
-			sql, rows := fc()
-			if rows == -1 {
-				l.Printf(l.traceErrStr, utils.FileWithLineNum(), err, float64(elapsed.Nanoseconds())/1e6, "-", sql)
-			} else {
-				l.Printf(l.traceErrStr, utils.FileWithLineNum(), err, float64(elapsed.Nanoseconds())/1e6, rows, sql)
-			}
-		case elapsed > l.SlowThreshold && l.SlowThreshold != 0 && l.LogLevel >= Warn:
-			sql, rows := fc()
-			slowLog := fmt.Sprintf("SLOW SQL >= %v", l.SlowThreshold)
-			if rows == -1 {
-				l.Printf(l.traceWarnStr, utils.FileWithLineNum(), slowLog, float64(elapsed.Nanoseconds())/1e6, "-", sql)
-			} else {
-				l.Printf(l.traceWarnStr, utils.FileWithLineNum(), slowLog, float64(elapsed.Nanoseconds())/1e6, rows, sql)
-			}
-		case l.LogLevel == Info:
-			sql, rows := fc()
-			if rows == -1 {
-				l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, "-", sql)
-			} else {
-				l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, rows, sql)
-			}
+//
+//nolint:cyclop
+func (l *logger) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
+	if l.LogLevel <= Silent {
+		return
+	}
+
+	elapsed := time.Since(begin)
+	switch {
+	case err != nil && l.LogLevel >= Error && (!errors.Is(err, ErrRecordNotFound) || !l.IgnoreRecordNotFoundError):
+		sql, rows := fc()
+		if rows == -1 {
+			l.Printf(l.traceErrStr, utils.FileWithLineNum(), err, float64(elapsed.Nanoseconds())/1e6, "-", sql)
+		} else {
+			l.Printf(l.traceErrStr, utils.FileWithLineNum(), err, float64(elapsed.Nanoseconds())/1e6, rows, sql)
+		}
+	case elapsed > l.SlowThreshold && l.SlowThreshold != 0 && l.LogLevel >= Warn:
+		sql, rows := fc()
+		slowLog := fmt.Sprintf("SLOW SQL >= %v", l.SlowThreshold)
+		if rows == -1 {
+			l.Printf(l.traceWarnStr, utils.FileWithLineNum(), slowLog, float64(elapsed.Nanoseconds())/1e6, "-", sql)
+		} else {
+			l.Printf(l.traceWarnStr, utils.FileWithLineNum(), slowLog, float64(elapsed.Nanoseconds())/1e6, rows, sql)
+		}
+	case l.LogLevel == Info:
+		sql, rows := fc()
+		if rows == -1 {
+			l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, "-", sql)
+		} else {
+			l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, rows, sql)
 		}
 	}
 }
 
+// ParamsFilter filter params
+func (l *logger) ParamsFilter(ctx context.Context, sql string, params ...interface{}) (string, []interface{}) {
+	if l.Config.ParameterizedQueries {
+		return sql, nil
+	}
+	return sql, params
+}
+
 type traceRecorder struct {
 	Interface
 	BeginAt      time.Time
@@ -172,12 +205,21 @@ type traceRecorder struct {
 	Err          error
 }
 
-func (l traceRecorder) New() *traceRecorder {
+// New trace recorder
+func (l *traceRecorder) New() *traceRecorder {
 	return &traceRecorder{Interface: l.Interface, BeginAt: time.Now()}
 }
 
+// Trace implement logger interface
 func (l *traceRecorder) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
 	l.BeginAt = begin
 	l.SQL, l.RowsAffected = fc()
 	l.Err = err
 }
+
+func (l *traceRecorder) ParamsFilter(ctx context.Context, sql string, params ...interface{}) (string, []interface{}) {
+	if RecorderParamsFilter == nil {
+		return sql, params
+	}
+	return RecorderParamsFilter(ctx, sql, params...)
+}

logger/sql.go

@@ -19,20 +19,40 @@ const (
 	nullStr     = "NULL"
 )
 
-func isPrintable(s []byte) bool {
+func isPrintable(s string) bool {
 	for _, r := range s {
-		if !unicode.IsPrint(rune(r)) {
+		if !unicode.IsPrint(r) {
 			return false
 		}
 	}
 	return true
 }
 
-var convertableTypes = []reflect.Type{reflect.TypeOf(time.Time{}), reflect.TypeOf(false), reflect.TypeOf([]byte{})}
+// A list of Go types that should be converted to SQL primitives
+var convertibleTypes = []reflect.Type{reflect.TypeOf(time.Time{}), reflect.TypeOf(false), reflect.TypeOf([]byte{})}
 
+// RegEx matches only numeric values
+var numericPlaceholderRe = regexp.MustCompile(`\$\d+\$`)
+
+func isNumeric(k reflect.Kind) bool {
+	switch k {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return true
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return true
+	case reflect.Float32, reflect.Float64:
+		return true
+	default:
+		return false
+	}
+}
+
+// ExplainSQL generate SQL string with given parameters, the generated SQL is expected to be used in logger, execute it might introduce a SQL injection vulnerability
 func ExplainSQL(sql string, numericPlaceholder *regexp.Regexp, escaper string, avars ...interface{}) string {
-	var convertParams func(interface{}, int)
-	var vars = make([]string, len(avars))
+	var (
+		convertParams func(interface{}, int)
+		vars          = make([]string, len(avars))
+	)
 
 	convertParams = func(v interface{}, idx int) {
 		switch v := v.(type) {
@@ -64,23 +84,36 @@ func ExplainSQL(sql string, numericPlaceholder *regexp.Regexp, escaper string, a
 			}
 		case fmt.Stringer:
 			reflectValue := reflect.ValueOf(v)
-			if v != nil && reflectValue.IsValid() && ((reflectValue.Kind() == reflect.Ptr && !reflectValue.IsNil()) || reflectValue.Kind() != reflect.Ptr) {
-				vars[idx] = escaper + strings.Replace(fmt.Sprintf("%v", v), escaper, "\\"+escaper, -1) + escaper
-			} else {
-				vars[idx] = nullStr
+			switch reflectValue.Kind() {
+			case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+				vars[idx] = fmt.Sprintf("%d", reflectValue.Interface())
+			case reflect.Float32, reflect.Float64:
+				vars[idx] = fmt.Sprintf("%.6f", reflectValue.Interface())
+			case reflect.Bool:
+				vars[idx] = fmt.Sprintf("%t", reflectValue.Interface())
+			case reflect.String:
+				vars[idx] = escaper + strings.ReplaceAll(fmt.Sprintf("%v", v), escaper, escaper+escaper) + escaper
+			default:
+				if v != nil && reflectValue.IsValid() && ((reflectValue.Kind() == reflect.Ptr && !reflectValue.IsNil()) || reflectValue.Kind() != reflect.Ptr) {
+					vars[idx] = escaper + strings.ReplaceAll(fmt.Sprintf("%v", v), escaper, escaper+escaper) + escaper
+				} else {
+					vars[idx] = nullStr
+				}
 			}
 		case []byte:
-			if isPrintable(v) {
-				vars[idx] = escaper + strings.Replace(string(v), escaper, "\\"+escaper, -1) + escaper
+			if s := string(v); isPrintable(s) {
+				vars[idx] = escaper + strings.ReplaceAll(s, escaper, escaper+escaper) + escaper
 			} else {
 				vars[idx] = escaper + "<binary>" + escaper
 			}
 		case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64:
 			vars[idx] = utils.ToString(v)
-		case float64, float32:
-			vars[idx] = fmt.Sprintf("%.6f", v)
+		case float32:
+			vars[idx] = strconv.FormatFloat(float64(v), 'f', -1, 32)
+		case float64:
+			vars[idx] = strconv.FormatFloat(v, 'f', -1, 64)
 		case string:
-			vars[idx] = escaper + strings.Replace(v, escaper, "\\"+escaper, -1) + escaper
+			vars[idx] = escaper + strings.ReplaceAll(v, escaper, escaper+escaper) + escaper
 		default:
 			rv := reflect.ValueOf(v)
 			if v == nil || !rv.IsValid() || rv.Kind() == reflect.Ptr && rv.IsNil() {
@@ -90,14 +123,20 @@ func ExplainSQL(sql string, numericPlaceholder *regexp.Regexp, escaper string, a
 				convertParams(v, idx)
 			} else if rv.Kind() == reflect.Ptr && !rv.IsZero() {
 				convertParams(reflect.Indirect(rv).Interface(), idx)
+			} else if isNumeric(rv.Kind()) {
+				if rv.CanInt() || rv.CanUint() {
+					vars[idx] = fmt.Sprintf("%d", rv.Interface())
+				} else {
+					vars[idx] = fmt.Sprintf("%.6f", rv.Interface())
+				}
 			} else {
-				for _, t := range convertableTypes {
+				for _, t := range convertibleTypes {
 					if rv.Type().ConvertibleTo(t) {
 						convertParams(rv.Convert(t).Interface(), idx)
 						return
 					}
 				}
-				vars[idx] = escaper + strings.Replace(fmt.Sprint(v), escaper, "\\"+escaper, -1) + escaper
+				vars[idx] = escaper + strings.ReplaceAll(fmt.Sprint(v), escaper, escaper+escaper) + escaper
 			}
 		}
 	}
@@ -124,9 +163,18 @@ func ExplainSQL(sql string, numericPlaceholder *regexp.Regexp, escaper string, a
 		sql = newSQL.String()
 	} else {
 		sql = numericPlaceholder.ReplaceAllString(sql, "$$$1$$")
-		for idx, v := range vars {
-			sql = strings.Replace(sql, "$"+strconv.Itoa(idx+1)+"$", v, 1)
-		}
+
+		sql = numericPlaceholderRe.ReplaceAllStringFunc(sql, func(v string) string {
+			num := v[1 : len(v)-1]
+			n, _ := strconv.Atoi(num)
+
+			// position var start from 1 ($1, $2)
+			n -= 1
+			if n >= 0 && n <= len(vars)-1 {
+				return vars[n]
+			}
+			return v
+		})
 	}
 
 	return sql

logger/sql_test.go

@@ -31,20 +31,24 @@ func (s ExampleStruct) Value() (driver.Value, error) {
 }
 
 func format(v []byte, escaper string) string {
-	return escaper + strings.Replace(string(v), escaper, "\\"+escaper, -1) + escaper
+	return escaper + strings.ReplaceAll(string(v), escaper, escaper+escaper) + escaper
 }
 
 func TestExplainSQL(t *testing.T) {
 	type role string
 	type password []byte
+	type intType int
+	type floatType float64
 	var (
-		tt     = now.MustParse("2020-02-23 11:10:10")
-		myrole = role("admin")
-		pwd    = password([]byte("pass"))
-		jsVal  = []byte(`{"Name":"test","Val":"test"}`)
-		js     = JSON(jsVal)
-		esVal  = []byte(`{"Name":"test","Val":"test"}`)
-		es     = ExampleStruct{Name: "test", Val: "test"}
+		tt                 = now.MustParse("2020-02-23 11:10:10")
+		myrole             = role("admin")
+		pwd                = password("pass")
+		jsVal              = []byte(`{"Name":"test","Val":"test"}`)
+		js                 = JSON(jsVal)
+		esVal              = []byte(`{"Name":"test","Val":"test"}`)
+		es                 = ExampleStruct{Name: "test", Val: "test"}
+		intVal   intType   = 1
+		floatVal floatType = 1.23
 	)
 
 	results := []struct {
@@ -57,43 +61,67 @@ func TestExplainSQL(t *testing.T) {
 			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
 			NumericRegexp: nil,
 			Vars:          []interface{}{"jinzhu", 1, 999.99, true, []byte("12345"), tt, &tt, nil, "w@g.\"com", myrole, pwd},
-			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu", 1, 999.990000, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.\"com", "admin", "pass")`,
+			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.""com", "admin", "pass")`,
 		},
 		{
 			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
 			NumericRegexp: nil,
 			Vars:          []interface{}{"jinzhu?", 1, 999.99, true, []byte("12345"), tt, &tt, nil, "w@g.\"com", myrole, pwd},
-			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu?", 1, 999.990000, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.\"com", "admin", "pass")`,
+			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu?", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.""com", "admin", "pass")`,
 		},
 		{
 			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values (@p1, @p2, @p3, @p4, @p5, @p6, @p7, @p8, @p9, @p10, @p11)",
 			NumericRegexp: regexp.MustCompile(`@p(\d+)`),
 			Vars:          []interface{}{"jinzhu", 1, 999.99, true, []byte("12345"), tt, &tt, nil, "w@g.com", myrole, pwd},
-			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu", 1, 999.990000, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.com", "admin", "pass")`,
+			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.com", "admin", "pass")`,
 		},
 		{
 			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ($3, $4, $1, $2, $7, $8, $5, $6, $9, $10, $11)",
 			NumericRegexp: regexp.MustCompile(`\$(\d+)`),
 			Vars:          []interface{}{999.99, true, "jinzhu", 1, &tt, nil, []byte("12345"), tt, "w@g.com", myrole, pwd},
-			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu", 1, 999.990000, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.com", "admin", "pass")`,
+			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.com", "admin", "pass")`,
 		},
 		{
 			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values (@p1, @p11, @p2, @p3, @p4, @p5, @p6, @p7, @p8, @p9, @p10)",
 			NumericRegexp: regexp.MustCompile(`@p(\d+)`),
 			Vars:          []interface{}{"jinzhu", 999.99, true, []byte("12345"), tt, &tt, nil, "w@g.com", myrole, pwd, 1},
-			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu", 1, 999.990000, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.com", "admin", "pass")`,
+			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass) values ("jinzhu", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.com", "admin", "pass")`,
 		},
 		{
 			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
 			NumericRegexp: nil,
 			Vars:          []interface{}{"jinzhu", 1, 999.99, true, []byte("12345"), tt, &tt, nil, "w@g.\"com", myrole, pwd, js, es},
-			Result:        fmt.Sprintf(`create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values ("jinzhu", 1, 999.990000, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.\"com", "admin", "pass", %v, %v)`, format(jsVal, `"`), format(esVal, `"`)),
+			Result:        fmt.Sprintf(`create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values ("jinzhu", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.""com", "admin", "pass", %v, %v)`, format(jsVal, `"`), format(esVal, `"`)),
 		},
 		{
 			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
 			NumericRegexp: nil,
 			Vars:          []interface{}{"jinzhu", 1, 999.99, true, []byte("12345"), tt, &tt, nil, "w@g.\"com", myrole, pwd, &js, &es},
-			Result:        fmt.Sprintf(`create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values ("jinzhu", 1, 999.990000, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.\"com", "admin", "pass", %v, %v)`, format(jsVal, `"`), format(esVal, `"`)),
+			Result:        fmt.Sprintf(`create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values ("jinzhu", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.""com", "admin", "pass", %v, %v)`, format(jsVal, `"`), format(esVal, `"`)),
+		},
+		{
+			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+			NumericRegexp: nil,
+			Vars:          []interface{}{"jinzhu", 1, 0.1753607109, true, []byte("12345"), tt, &tt, nil, "w@g.\"com", myrole, pwd, &js, &es},
+			Result:        fmt.Sprintf(`create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values ("jinzhu", 1, 0.1753607109, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.""com", "admin", "pass", %v, %v)`, format(jsVal, `"`), format(esVal, `"`)),
+		},
+		{
+			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+			NumericRegexp: nil,
+			Vars:          []interface{}{"jinzhu", 1, float32(999.99), true, []byte("12345"), tt, &tt, nil, "w@g.\"com", myrole, pwd, &js, &es},
+			Result:        fmt.Sprintf(`create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, json_struct, example_struct) values ("jinzhu", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.""com", "admin", "pass", %v, %v)`, format(jsVal, `"`), format(esVal, `"`)),
+		},
+		{
+			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, int_val) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+			NumericRegexp: nil,
+			Vars:          []interface{}{"jinzhu?", 1, 999.99, true, []byte("12345"), tt, &tt, nil, "w@g.\"com", myrole, pwd, intVal},
+			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, int_val) values ("jinzhu?", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.""com", "admin", "pass", 1)`,
+		},
+		{
+			SQL:           "create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, float_val) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+			NumericRegexp: nil,
+			Vars:          []interface{}{"jinzhu?", 1, 999.99, true, []byte("12345"), tt, &tt, nil, "w@g.\"com", myrole, pwd, floatVal},
+			Result:        `create table users (name, age, height, actived, bytes, create_at, update_at, deleted_at, email, role, pass, float_val) values ("jinzhu?", 1, 999.99, true, "12345", "2020-02-23 11:10:10", "2020-02-23 11:10:10", NULL, "w@g.""com", "admin", "pass", 1.230000)`,
 		},
 	}
 

migrator.go

@@ -1,22 +1,22 @@
 package gorm
 
 import (
+	"reflect"
+
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/schema"
 )
 
 // Migrator returns migrator
 func (db *DB) Migrator() Migrator {
+	tx := db.getInstance()
+
 	// apply scopes to migrator
-	for len(db.Statement.scopes) > 0 {
-		scopes := db.Statement.scopes
-		db.Statement.scopes = nil
-		for _, scope := range scopes {
-			db = scope(db)
-		}
+	for len(tx.Statement.scopes) > 0 {
+		tx = tx.executeScopes()
 	}
 
-	return db.Dialector.Migrator(db.Session(&Session{}))
+	return tx.Dialector.Migrator(tx.Session(&Session{}))
 }
 
 // AutoMigrate run auto migration for given models
@@ -26,19 +26,45 @@ func (db *DB) AutoMigrate(dst ...interface{}) error {
 
 // ViewOption view option
 type ViewOption struct {
-	Replace     bool
-	CheckOption string
-	Query       *DB
+	Replace     bool   // If true, exec `CREATE`. If false, exec `CREATE OR REPLACE`
+	CheckOption string // optional. e.g. `WITH [ CASCADED | LOCAL ] CHECK OPTION`
+	Query       *DB    // required subquery.
 }
 
+// ColumnType column type interface
 type ColumnType interface {
 	Name() string
-	DatabaseTypeName() string
+	DatabaseTypeName() string                 // varchar
+	ColumnType() (columnType string, ok bool) // varchar(64)
+	PrimaryKey() (isPrimaryKey bool, ok bool)
+	AutoIncrement() (isAutoIncrement bool, ok bool)
 	Length() (length int64, ok bool)
 	DecimalSize() (precision int64, scale int64, ok bool)
 	Nullable() (nullable bool, ok bool)
+	Unique() (unique bool, ok bool)
+	ScanType() reflect.Type
+	Comment() (value string, ok bool)
+	DefaultValue() (value string, ok bool)
 }
 
+type Index interface {
+	Table() string
+	Name() string
+	Columns() []string
+	PrimaryKey() (isPrimaryKey bool, ok bool)
+	Unique() (unique bool, ok bool)
+	Option() string
+}
+
+// TableType table type interface
+type TableType interface {
+	Schema() string
+	Name() string
+	Type() string
+	Comment() (comment string, ok bool)
+}
+
+// Migrator migrator interface
 type Migrator interface {
 	// AutoMigrate
 	AutoMigrate(dst ...interface{}) error
@@ -46,18 +72,23 @@ type Migrator interface {
 	// Database
 	CurrentDatabase() string
 	FullDataTypeOf(*schema.Field) clause.Expr
+	GetTypeAliases(databaseTypeName string) []string
 
 	// Tables
 	CreateTable(dst ...interface{}) error
 	DropTable(dst ...interface{}) error
 	HasTable(dst interface{}) bool
 	RenameTable(oldName, newName interface{}) error
+	GetTables() (tableList []string, err error)
+	TableType(dst interface{}) (TableType, error)
 
 	// Columns
 	AddColumn(dst interface{}, field string) error
 	DropColumn(dst interface{}, field string) error
 	AlterColumn(dst interface{}, field string) error
 	MigrateColumn(dst interface{}, field *schema.Field, columnType ColumnType) error
+	// MigrateColumnUnique migrate column's UNIQUE constraint, it's part of MigrateColumn.
+	MigrateColumnUnique(dst interface{}, field *schema.Field, columnType ColumnType) error
 	HasColumn(dst interface{}, field string) bool
 	RenameColumn(dst interface{}, oldName, field string) error
 	ColumnTypes(dst interface{}) ([]ColumnType, error)
@@ -76,4 +107,5 @@ type Migrator interface {
 	DropIndex(dst interface{}, name string) error
 	HasIndex(dst interface{}, name string) bool
 	RenameIndex(dst interface{}, oldName, newName string) error
+	GetIndexes(dst interface{}) ([]Index, error)
 }

migrator/column_type.go

@@ -0,0 +1,107 @@
+package migrator
+
+import (
+	"database/sql"
+	"reflect"
+)
+
+// ColumnType column type implements ColumnType interface
+type ColumnType struct {
+	SQLColumnType      *sql.ColumnType
+	NameValue          sql.NullString
+	DataTypeValue      sql.NullString
+	ColumnTypeValue    sql.NullString
+	PrimaryKeyValue    sql.NullBool
+	UniqueValue        sql.NullBool
+	AutoIncrementValue sql.NullBool
+	LengthValue        sql.NullInt64
+	DecimalSizeValue   sql.NullInt64
+	ScaleValue         sql.NullInt64
+	NullableValue      sql.NullBool
+	ScanTypeValue      reflect.Type
+	CommentValue       sql.NullString
+	DefaultValueValue  sql.NullString
+}
+
+// Name returns the name or alias of the column.
+func (ct ColumnType) Name() string {
+	if ct.NameValue.Valid {
+		return ct.NameValue.String
+	}
+	return ct.SQLColumnType.Name()
+}
+
+// DatabaseTypeName returns the database system name of the column type. If an empty
+// string is returned, then the driver type name is not supported.
+// Consult your driver documentation for a list of driver data types. Length specifiers
+// are not included.
+// Common type names include "VARCHAR", "TEXT", "NVARCHAR", "DECIMAL", "BOOL",
+// "INT", and "BIGINT".
+func (ct ColumnType) DatabaseTypeName() string {
+	if ct.DataTypeValue.Valid {
+		return ct.DataTypeValue.String
+	}
+	return ct.SQLColumnType.DatabaseTypeName()
+}
+
+// ColumnType returns the database type of the column. like `varchar(16)`
+func (ct ColumnType) ColumnType() (columnType string, ok bool) {
+	return ct.ColumnTypeValue.String, ct.ColumnTypeValue.Valid
+}
+
+// PrimaryKey returns the column is primary key or not.
+func (ct ColumnType) PrimaryKey() (isPrimaryKey bool, ok bool) {
+	return ct.PrimaryKeyValue.Bool, ct.PrimaryKeyValue.Valid
+}
+
+// AutoIncrement returns the column is auto increment or not.
+func (ct ColumnType) AutoIncrement() (isAutoIncrement bool, ok bool) {
+	return ct.AutoIncrementValue.Bool, ct.AutoIncrementValue.Valid
+}
+
+// Length returns the column type length for variable length column types
+func (ct ColumnType) Length() (length int64, ok bool) {
+	if ct.LengthValue.Valid {
+		return ct.LengthValue.Int64, true
+	}
+	return ct.SQLColumnType.Length()
+}
+
+// DecimalSize returns the scale and precision of a decimal type.
+func (ct ColumnType) DecimalSize() (precision int64, scale int64, ok bool) {
+	if ct.DecimalSizeValue.Valid {
+		return ct.DecimalSizeValue.Int64, ct.ScaleValue.Int64, true
+	}
+	return ct.SQLColumnType.DecimalSize()
+}
+
+// Nullable reports whether the column may be null.
+func (ct ColumnType) Nullable() (nullable bool, ok bool) {
+	if ct.NullableValue.Valid {
+		return ct.NullableValue.Bool, true
+	}
+	return ct.SQLColumnType.Nullable()
+}
+
+// Unique reports whether the column may be unique.
+func (ct ColumnType) Unique() (unique bool, ok bool) {
+	return ct.UniqueValue.Bool, ct.UniqueValue.Valid
+}
+
+// ScanType returns a Go type suitable for scanning into using Rows.Scan.
+func (ct ColumnType) ScanType() reflect.Type {
+	if ct.ScanTypeValue != nil {
+		return ct.ScanTypeValue
+	}
+	return ct.SQLColumnType.ScanType()
+}
+
+// Comment returns the comment of current column.
+func (ct ColumnType) Comment() (value string, ok bool) {
+	return ct.CommentValue.String, ct.CommentValue.Valid
+}
+
+// DefaultValue returns the default value of current column.
+func (ct ColumnType) DefaultValue() (value string, ok bool) {
+	return ct.DefaultValueValue.String, ct.DefaultValueValue.Valid
+}

migrator/index.go

@@ -0,0 +1,43 @@
+package migrator
+
+import "database/sql"
+
+// Index implements gorm.Index interface
+type Index struct {
+	TableName       string
+	NameValue       string
+	ColumnList      []string
+	PrimaryKeyValue sql.NullBool
+	UniqueValue     sql.NullBool
+	OptionValue     string
+}
+
+// Table return the table name of the index.
+func (idx Index) Table() string {
+	return idx.TableName
+}
+
+// Name return the name of the index.
+func (idx Index) Name() string {
+	return idx.NameValue
+}
+
+// Columns return the columns of the index
+func (idx Index) Columns() []string {
+	return idx.ColumnList
+}
+
+// PrimaryKey returns the index is primary key or not.
+func (idx Index) PrimaryKey() (isPrimaryKey bool, ok bool) {
+	return idx.PrimaryKeyValue.Bool, idx.PrimaryKeyValue.Valid
+}
+
+// Unique returns whether the index is unique or not.
+func (idx Index) Unique() (unique bool, ok bool) {
+	return idx.UniqueValue.Bool, idx.UniqueValue.Valid
+}
+
+// Option return the optional attribute of the index
+func (idx Index) Option() string {
+	return idx.OptionValue
+}

migrator/table_type.go

@@ -0,0 +1,33 @@
+package migrator
+
+import (
+	"database/sql"
+)
+
+// TableType table type implements TableType interface
+type TableType struct {
+	SchemaValue  string
+	NameValue    string
+	TypeValue    string
+	CommentValue sql.NullString
+}
+
+// Schema returns the schema of the table.
+func (ct TableType) Schema() string {
+	return ct.SchemaValue
+}
+
+// Name returns the name of the table.
+func (ct TableType) Name() string {
+	return ct.NameValue
+}
+
+// Type returns the type of the table.
+func (ct TableType) Type() string {
+	return ct.TypeValue
+}
+
+// Comment returns the comment of current table.
+func (ct TableType) Comment() (comment string, ok bool) {
+	return ct.CommentValue.String, ct.CommentValue.Valid
+}

model.go

@@ -4,9 +4,10 @@ import "time"
 
 // Model a basic GoLang struct which includes the following fields: ID, CreatedAt, UpdatedAt, DeletedAt
 // It may be embedded into your model or you may build your own model without it
-//    type User struct {
-//      gorm.Model
-//    }
+//
+//	type User struct {
+//	  gorm.Model
+//	}
 type Model struct {
 	ID        uint `gorm:"primarykey"`
 	CreatedAt time.Time

prepare_stmt.go

@@ -3,58 +3,86 @@ package gorm
 import (
 	"context"
 	"database/sql"
+	"database/sql/driver"
+	"errors"
+	"reflect"
 	"sync"
+	"time"
+
+	"gorm.io/gorm/internal/stmt_store"
 )
 
-type Stmt struct {
-	*sql.Stmt
-	Transaction bool
-}
-
 type PreparedStmtDB struct {
-	Stmts       map[string]Stmt
-	PreparedSQL []string
-	Mux         *sync.RWMutex
+	Stmts stmt_store.Store
+	Mux   *sync.RWMutex
 	ConnPool
 }
 
-func (db *PreparedStmtDB) Close() {
-	db.Mux.Lock()
-	for _, query := range db.PreparedSQL {
-		if stmt, ok := db.Stmts[query]; ok {
-			delete(db.Stmts, query)
-			stmt.Close()
-		}
+// NewPreparedStmtDB creates and initializes a new instance of PreparedStmtDB.
+//
+// Parameters:
+// - connPool: A connection pool that implements the ConnPool interface, used for managing database connections.
+// - maxSize: The maximum number of prepared statements that can be stored in the statement store.
+// - ttl: The time-to-live duration for each prepared statement in the store. Statements older than this duration will be automatically removed.
+//
+// Returns:
+// - A pointer to a PreparedStmtDB instance, which manages prepared statements using the provided connection pool and configuration.
+func NewPreparedStmtDB(connPool ConnPool, maxSize int, ttl time.Duration) *PreparedStmtDB {
+	return &PreparedStmtDB{
+		ConnPool: connPool,                     // Assigns the provided connection pool to manage database connections.
+		Stmts:    stmt_store.New(maxSize, ttl), // Initializes a new statement store with the specified maximum size and TTL.
+		Mux:      &sync.RWMutex{},              // Sets up a read-write mutex for synchronizing access to the statement store.
 	}
-
-	db.Mux.Unlock()
 }
 
-func (db *PreparedStmtDB) prepare(ctx context.Context, conn ConnPool, isTransaction bool, query string) (Stmt, error) {
+// GetDBConn returns the underlying *sql.DB connection
+func (db *PreparedStmtDB) GetDBConn() (*sql.DB, error) {
+	if sqldb, ok := db.ConnPool.(*sql.DB); ok {
+		return sqldb, nil
+	}
+
+	if dbConnector, ok := db.ConnPool.(GetDBConnector); ok && dbConnector != nil {
+		return dbConnector.GetDBConn()
+	}
+
+	return nil, ErrInvalidDB
+}
+
+// Close closes all prepared statements in the store
+func (db *PreparedStmtDB) Close() {
+	db.Mux.Lock()
+	defer db.Mux.Unlock()
+
+	for _, key := range db.Stmts.Keys() {
+		db.Stmts.Delete(key)
+	}
+}
+
+// Reset Deprecated use Close instead
+func (db *PreparedStmtDB) Reset() {
+	db.Close()
+}
+
+func (db *PreparedStmtDB) prepare(ctx context.Context, conn ConnPool, isTransaction bool, query string) (_ *stmt_store.Stmt, err error) {
 	db.Mux.RLock()
-	if stmt, ok := db.Stmts[query]; ok && (!stmt.Transaction || isTransaction) {
-		db.Mux.RUnlock()
-		return stmt, nil
+	if db.Stmts != nil {
+		if stmt, ok := db.Stmts.Get(query); ok && (!stmt.Transaction || isTransaction) {
+			db.Mux.RUnlock()
+			return stmt, stmt.Error()
+		}
 	}
 	db.Mux.RUnlock()
 
+	// retry
 	db.Mux.Lock()
-	// double check
-	if stmt, ok := db.Stmts[query]; ok && (!stmt.Transaction || isTransaction) {
-		db.Mux.Unlock()
-		return stmt, nil
-	} else if ok {
-		stmt.Close()
+	if db.Stmts != nil {
+		if stmt, ok := db.Stmts.Get(query); ok && (!stmt.Transaction || isTransaction) {
+			db.Mux.Unlock()
+			return stmt, stmt.Error()
+		}
 	}
 
-	stmt, err := conn.PrepareContext(ctx, query)
-	if err == nil {
-		db.Stmts[query] = Stmt{Stmt: stmt, Transaction: isTransaction}
-		db.PreparedSQL = append(db.PreparedSQL, query)
-	}
-	db.Mux.Unlock()
-
-	return db.Stmts[query], err
+	return db.Stmts.New(ctx, query, isTransaction, conn, db.Mux)
 }
 
 func (db *PreparedStmtDB) BeginTx(ctx context.Context, opt *sql.TxOptions) (ConnPool, error) {
@@ -62,6 +90,19 @@ func (db *PreparedStmtDB) BeginTx(ctx context.Context, opt *sql.TxOptions) (Conn
 		tx, err := beginner.BeginTx(ctx, opt)
 		return &PreparedStmtTX{PreparedStmtDB: db, Tx: tx}, err
 	}
+
+	beginner, ok := db.ConnPool.(ConnPoolBeginner)
+	if !ok {
+		return nil, ErrInvalidTransaction
+	}
+
+	connPool, err := beginner.BeginTx(ctx, opt)
+	if err != nil {
+		return nil, err
+	}
+	if tx, ok := connPool.(Tx); ok {
+		return &PreparedStmtTX{PreparedStmtDB: db, Tx: tx}, nil
+	}
 	return nil, ErrInvalidTransaction
 }
 
@@ -69,11 +110,8 @@ func (db *PreparedStmtDB) ExecContext(ctx context.Context, query string, args ..
 	stmt, err := db.prepare(ctx, db.ConnPool, false, query)
 	if err == nil {
 		result, err = stmt.ExecContext(ctx, args...)
-		if err != nil {
-			db.Mux.Lock()
-			stmt.Close()
-			delete(db.Stmts, query)
-			db.Mux.Unlock()
+		if errors.Is(err, driver.ErrBadConn) {
+			db.Stmts.Delete(query)
 		}
 	}
 	return result, err
@@ -83,11 +121,8 @@ func (db *PreparedStmtDB) QueryContext(ctx context.Context, query string, args .
 	stmt, err := db.prepare(ctx, db.ConnPool, false, query)
 	if err == nil {
 		rows, err = stmt.QueryContext(ctx, args...)
-		if err != nil {
-			db.Mux.Lock()
-			stmt.Close()
-			delete(db.Stmts, query)
-			db.Mux.Unlock()
+		if errors.Is(err, driver.ErrBadConn) {
+			db.Stmts.Delete(query)
 		}
 	}
 	return rows, err
@@ -101,20 +136,32 @@ func (db *PreparedStmtDB) QueryRowContext(ctx context.Context, query string, arg
 	return &sql.Row{}
 }
 
+func (db *PreparedStmtDB) Ping() error {
+	conn, err := db.GetDBConn()
+	if err != nil {
+		return err
+	}
+	return conn.Ping()
+}
+
 type PreparedStmtTX struct {
-	*sql.Tx
+	Tx
 	PreparedStmtDB *PreparedStmtDB
 }
 
+func (db *PreparedStmtTX) GetDBConn() (*sql.DB, error) {
+	return db.PreparedStmtDB.GetDBConn()
+}
+
 func (tx *PreparedStmtTX) Commit() error {
-	if tx.Tx != nil {
+	if tx.Tx != nil && !reflect.ValueOf(tx.Tx).IsNil() {
 		return tx.Tx.Commit()
 	}
 	return ErrInvalidTransaction
 }
 
 func (tx *PreparedStmtTX) Rollback() error {
-	if tx.Tx != nil {
+	if tx.Tx != nil && !reflect.ValueOf(tx.Tx).IsNil() {
 		return tx.Tx.Rollback()
 	}
 	return ErrInvalidTransaction
@@ -124,11 +171,8 @@ func (tx *PreparedStmtTX) ExecContext(ctx context.Context, query string, args ..
 	stmt, err := tx.PreparedStmtDB.prepare(ctx, tx.Tx, true, query)
 	if err == nil {
 		result, err = tx.Tx.StmtContext(ctx, stmt.Stmt).ExecContext(ctx, args...)
-		if err != nil {
-			tx.PreparedStmtDB.Mux.Lock()
-			stmt.Close()
-			delete(tx.PreparedStmtDB.Stmts, query)
-			tx.PreparedStmtDB.Mux.Unlock()
+		if errors.Is(err, driver.ErrBadConn) {
+			tx.PreparedStmtDB.Stmts.Delete(query)
 		}
 	}
 	return result, err
@@ -137,12 +181,9 @@ func (tx *PreparedStmtTX) ExecContext(ctx context.Context, query string, args ..
 func (tx *PreparedStmtTX) QueryContext(ctx context.Context, query string, args ...interface{}) (rows *sql.Rows, err error) {
 	stmt, err := tx.PreparedStmtDB.prepare(ctx, tx.Tx, true, query)
 	if err == nil {
-		rows, err = tx.Tx.Stmt(stmt.Stmt).QueryContext(ctx, args...)
-		if err != nil {
-			tx.PreparedStmtDB.Mux.Lock()
-			stmt.Close()
-			delete(tx.PreparedStmtDB.Stmts, query)
-			tx.PreparedStmtDB.Mux.Unlock()
+		rows, err = tx.Tx.StmtContext(ctx, stmt.Stmt).QueryContext(ctx, args...)
+		if errors.Is(err, driver.ErrBadConn) {
+			tx.PreparedStmtDB.Stmts.Delete(query)
 		}
 	}
 	return rows, err
@@ -155,3 +196,11 @@ func (tx *PreparedStmtTX) QueryRowContext(ctx context.Context, query string, arg
 	}
 	return &sql.Row{}
 }
+
+func (tx *PreparedStmtTX) Ping() error {
+	conn, err := tx.GetDBConn()
+	if err != nil {
+		return err
+	}
+	return conn.Ping()
+}

scan.go

@@ -8,13 +8,15 @@ import (
 	"time"
 
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils"
 )
 
+// prepareValues prepare values slice
 func prepareValues(values []interface{}, db *DB, columnTypes []*sql.ColumnType, columns []string) {
 	if db.Statement.Schema != nil {
 		for idx, name := range columns {
 			if field := db.Statement.Schema.LookUpField(name); field != nil {
-				values[idx] = reflect.New(reflect.PtrTo(field.FieldType)).Interface()
+				values[idx] = reflect.New(reflect.PointerTo(field.FieldType)).Interface()
 				continue
 			}
 			values[idx] = new(interface{})
@@ -22,7 +24,7 @@ func prepareValues(values []interface{}, db *DB, columnTypes []*sql.ColumnType,
 	} else if len(columnTypes) > 0 {
 		for idx, columnType := range columnTypes {
 			if columnType.ScanType() != nil {
-				values[idx] = reflect.New(reflect.PtrTo(columnType.ScanType())).Interface()
+				values[idx] = reflect.New(reflect.PointerTo(columnType.ScanType())).Interface()
 			} else {
 				values[idx] = new(interface{})
 			}
@@ -49,9 +51,96 @@ func scanIntoMap(mapValue map[string]interface{}, values []interface{}, columns
 	}
 }
 
-func Scan(rows *sql.Rows, db *DB, initialized bool) {
-	columns, _ := rows.Columns()
-	values := make([]interface{}, len(columns))
+func (db *DB) scanIntoStruct(rows Rows, reflectValue reflect.Value, values []interface{}, fields []*schema.Field, joinFields [][]*schema.Field) {
+	for idx, field := range fields {
+		if field != nil {
+			values[idx] = field.NewValuePool.Get()
+		} else if len(fields) == 1 {
+			if reflectValue.CanAddr() {
+				values[idx] = reflectValue.Addr().Interface()
+			} else {
+				values[idx] = reflectValue.Interface()
+			}
+		}
+	}
+
+	db.RowsAffected++
+	db.AddError(rows.Scan(values...))
+	joinedNestedSchemaMap := make(map[string]interface{})
+	for idx, field := range fields {
+		if field == nil {
+			continue
+		}
+
+		if len(joinFields) == 0 || len(joinFields[idx]) == 0 {
+			db.AddError(field.Set(db.Statement.Context, reflectValue, values[idx]))
+		} else { // joinFields count is larger than 2 when using join
+			var isNilPtrValue bool
+			var relValue reflect.Value
+			// does not contain raw dbname
+			nestedJoinSchemas := joinFields[idx][:len(joinFields[idx])-1]
+			// current reflect value
+			currentReflectValue := reflectValue
+			fullRels := make([]string, 0, len(nestedJoinSchemas))
+			for _, joinSchema := range nestedJoinSchemas {
+				fullRels = append(fullRels, joinSchema.Name)
+				relValue = joinSchema.ReflectValueOf(db.Statement.Context, currentReflectValue)
+				if relValue.Kind() == reflect.Ptr {
+					fullRelsName := utils.JoinNestedRelationNames(fullRels)
+					// same nested structure
+					if _, ok := joinedNestedSchemaMap[fullRelsName]; !ok {
+						if value := reflect.ValueOf(values[idx]).Elem(); value.Kind() == reflect.Ptr && value.IsNil() {
+							isNilPtrValue = true
+							break
+						}
+
+						relValue.Set(reflect.New(relValue.Type().Elem()))
+						joinedNestedSchemaMap[fullRelsName] = nil
+					}
+				}
+				currentReflectValue = relValue
+			}
+
+			if !isNilPtrValue { // ignore if value is nil
+				f := joinFields[idx][len(joinFields[idx])-1]
+				db.AddError(f.Set(db.Statement.Context, relValue, values[idx]))
+			}
+		}
+
+		// release data to pool
+		field.NewValuePool.Put(values[idx])
+	}
+}
+
+// ScanMode scan data mode
+type ScanMode uint8
+
+// scan modes
+const (
+	ScanInitialized         ScanMode = 1 << 0 // 1
+	ScanUpdate              ScanMode = 1 << 1 // 2
+	ScanOnConflictDoNothing ScanMode = 1 << 2 // 4
+)
+
+// Scan scan rows into db statement
+func Scan(rows Rows, db *DB, mode ScanMode) {
+	var (
+		columns, _          = rows.Columns()
+		values              = make([]interface{}, len(columns))
+		initialized         = mode&ScanInitialized != 0
+		update              = mode&ScanUpdate != 0
+		onConflictDonothing = mode&ScanOnConflictDoNothing != 0
+	)
+
+	if len(db.Statement.ColumnMapping) > 0 {
+		for i, column := range columns {
+			v, ok := db.Statement.ColumnMapping[column]
+			if ok {
+				columns[i] = v
+			}
+		}
+	}
+
 	db.RowsAffected = 0
 
 	switch dest := db.Statement.Dest.(type) {
@@ -66,6 +155,9 @@ func Scan(rows *sql.Rows, db *DB, initialized bool) {
 			mapValue, ok := dest.(map[string]interface{})
 			if !ok {
 				if v, ok := dest.(*map[string]interface{}); ok {
+					if *v == nil {
+						*v = map[string]interface{}{}
+					}
 					mapValue = *v
 				}
 			}
@@ -96,152 +188,182 @@ func Scan(rows *sql.Rows, db *DB, initialized bool) {
 			db.AddError(rows.Scan(dest))
 		}
 	default:
-		Schema := db.Statement.Schema
+		var (
+			fields       = make([]*schema.Field, len(columns))
+			joinFields   [][]*schema.Field
+			sch          = db.Statement.Schema
+			reflectValue = db.Statement.ReflectValue
+		)
 
-		switch db.Statement.ReflectValue.Kind() {
-		case reflect.Slice, reflect.Array:
-			var (
-				reflectValueType = db.Statement.ReflectValue.Type().Elem()
-				isPtr            = reflectValueType.Kind() == reflect.Ptr
-				fields           = make([]*schema.Field, len(columns))
-				joinFields       [][2]*schema.Field
-			)
+		if reflectValue.Kind() == reflect.Interface {
+			reflectValue = reflectValue.Elem()
+		}
 
-			if isPtr {
-				reflectValueType = reflectValueType.Elem()
+		reflectValueType := reflectValue.Type()
+		switch reflectValueType.Kind() {
+		case reflect.Array, reflect.Slice:
+			reflectValueType = reflectValueType.Elem()
+		}
+		isPtr := reflectValueType.Kind() == reflect.Ptr
+		if isPtr {
+			reflectValueType = reflectValueType.Elem()
+		}
+
+		if sch != nil {
+			if reflectValueType != sch.ModelType && reflectValueType.Kind() == reflect.Struct {
+				sch, _ = schema.Parse(db.Statement.Dest, db.cacheStore, db.NamingStrategy)
 			}
 
-			db.Statement.ReflectValue.Set(reflect.MakeSlice(db.Statement.ReflectValue.Type(), 0, 20))
-
-			if Schema != nil {
-				if reflectValueType != Schema.ModelType && reflectValueType.Kind() == reflect.Struct {
-					Schema, _ = schema.Parse(db.Statement.Dest, db.cacheStore, db.NamingStrategy)
+			if len(columns) == 1 {
+				// Is Pluck
+				if _, ok := reflect.New(reflectValueType).Interface().(sql.Scanner); (reflectValueType != sch.ModelType && ok) || // is scanner
+					reflectValueType.Kind() != reflect.Struct || // is not struct
+					sch.ModelType.ConvertibleTo(schema.TimeReflectType) { // is time
+					sch = nil
 				}
+			}
 
+			// Not Pluck
+			if sch != nil {
+				matchedFieldCount := make(map[string]int, len(columns))
 				for idx, column := range columns {
-					if field := Schema.LookUpField(column); field != nil && field.Readable {
+					if field := sch.LookUpField(column); field != nil && field.Readable {
 						fields[idx] = field
-					} else if names := strings.Split(column, "__"); len(names) > 1 {
-						if rel, ok := Schema.Relationships.Relations[names[0]]; ok {
-							if field := rel.FieldSchema.LookUpField(strings.Join(names[1:], "__")); field != nil && field.Readable {
+						if count, ok := matchedFieldCount[column]; ok {
+							// handle duplicate fields
+							for _, selectField := range sch.Fields {
+								if selectField.DBName == column && selectField.Readable {
+									if count == 0 {
+										matchedFieldCount[column]++
+										fields[idx] = selectField
+										break
+									}
+									count--
+								}
+							}
+						} else {
+							matchedFieldCount[column] = 1
+						}
+					} else if names := utils.SplitNestedRelationName(column); len(names) > 1 { // has nested relation
+						aliasName := utils.JoinNestedRelationNames(names[0 : len(names)-1])
+						for _, join := range db.Statement.Joins {
+							if join.Alias == aliasName {
+								names = append(strings.Split(join.Name, "."), names[len(names)-1])
+								break
+							}
+						}
+
+						if rel, ok := sch.Relationships.Relations[names[0]]; ok {
+							subNameCount := len(names)
+							// nested relation fields
+							relFields := make([]*schema.Field, 0, subNameCount-1)
+							relFields = append(relFields, rel.Field)
+							for _, name := range names[1 : subNameCount-1] {
+								rel = rel.FieldSchema.Relationships.Relations[name]
+								relFields = append(relFields, rel.Field)
+							}
+							// latest name is raw dbname
+							dbName := names[subNameCount-1]
+							if field := rel.FieldSchema.LookUpField(dbName); field != nil && field.Readable {
 								fields[idx] = field
 
 								if len(joinFields) == 0 {
-									joinFields = make([][2]*schema.Field, len(columns))
+									joinFields = make([][]*schema.Field, len(columns))
 								}
-								joinFields[idx] = [2]*schema.Field{rel.Field, field}
+								relFields = append(relFields, field)
+								joinFields[idx] = relFields
 								continue
 							}
 						}
-						values[idx] = &sql.RawBytes{}
+						var val interface{}
+						values[idx] = &val
 					} else {
-						values[idx] = &sql.RawBytes{}
-					}
-				}
-			}
-
-			// pluck values into slice of data
-			isPluck := false
-			if len(fields) == 1 {
-				if _, ok := reflect.New(reflectValueType).Interface().(sql.Scanner); ok || // is scanner
-					reflectValueType.Kind() != reflect.Struct || // is not struct
-					Schema.ModelType.ConvertibleTo(schema.TimeReflectType) { // is time
-					isPluck = true
-				}
-			}
-
-			for initialized || rows.Next() {
-				initialized = false
-				db.RowsAffected++
-
-				elem := reflect.New(reflectValueType)
-				if isPluck {
-					db.AddError(rows.Scan(elem.Interface()))
-				} else {
-					for idx, field := range fields {
-						if field != nil {
-							values[idx] = reflect.New(reflect.PtrTo(field.IndirectFieldType)).Interface()
-						}
-					}
-
-					db.AddError(rows.Scan(values...))
-
-					for idx, field := range fields {
-						if len(joinFields) != 0 && joinFields[idx][0] != nil {
-							value := reflect.ValueOf(values[idx]).Elem()
-							relValue := joinFields[idx][0].ReflectValueOf(elem)
-
-							if relValue.Kind() == reflect.Ptr && relValue.IsNil() {
-								if value.IsNil() {
-									continue
-								}
-								relValue.Set(reflect.New(relValue.Type().Elem()))
-							}
-
-							field.Set(relValue, values[idx])
-						} else if field != nil {
-							field.Set(elem, values[idx])
-						}
-					}
-				}
-
-				if isPtr {
-					db.Statement.ReflectValue.Set(reflect.Append(db.Statement.ReflectValue, elem))
-				} else {
-					db.Statement.ReflectValue.Set(reflect.Append(db.Statement.ReflectValue, elem.Elem()))
-				}
-			}
-		case reflect.Struct, reflect.Ptr:
-			if db.Statement.ReflectValue.Type() != Schema.ModelType {
-				Schema, _ = schema.Parse(db.Statement.Dest, db.cacheStore, db.NamingStrategy)
-			}
-
-			if initialized || rows.Next() {
-				for idx, column := range columns {
-					if field := Schema.LookUpField(column); field != nil && field.Readable {
-						values[idx] = reflect.New(reflect.PtrTo(field.IndirectFieldType)).Interface()
-					} else if names := strings.Split(column, "__"); len(names) > 1 {
-						if rel, ok := Schema.Relationships.Relations[names[0]]; ok {
-							if field := rel.FieldSchema.LookUpField(strings.Join(names[1:], "__")); field != nil && field.Readable {
-								values[idx] = reflect.New(reflect.PtrTo(field.IndirectFieldType)).Interface()
-								continue
-							}
-						}
-						values[idx] = &sql.RawBytes{}
-					} else {
-						values[idx] = &sql.RawBytes{}
-					}
-				}
-
-				db.RowsAffected++
-				db.AddError(rows.Scan(values...))
-
-				for idx, column := range columns {
-					if field := Schema.LookUpField(column); field != nil && field.Readable {
-						field.Set(db.Statement.ReflectValue, values[idx])
-					} else if names := strings.Split(column, "__"); len(names) > 1 {
-						if rel, ok := Schema.Relationships.Relations[names[0]]; ok {
-							if field := rel.FieldSchema.LookUpField(strings.Join(names[1:], "__")); field != nil && field.Readable {
-								relValue := rel.Field.ReflectValueOf(db.Statement.ReflectValue)
-								value := reflect.ValueOf(values[idx]).Elem()
-
-								if relValue.Kind() == reflect.Ptr && relValue.IsNil() {
-									if value.IsNil() {
-										continue
-									}
-									relValue.Set(reflect.New(relValue.Type().Elem()))
-								}
-
-								field.Set(relValue, values[idx])
-							}
-						}
+						var val interface{}
+						values[idx] = &val
 					}
 				}
 			}
 		}
+
+		switch reflectValue.Kind() {
+		case reflect.Slice, reflect.Array:
+			var (
+				elem        reflect.Value
+				isArrayKind = reflectValue.Kind() == reflect.Array
+			)
+
+			if !update || reflectValue.Len() == 0 {
+				update = false
+				if isArrayKind {
+					db.Statement.ReflectValue.Set(reflect.Zero(reflectValue.Type()))
+				} else {
+					// if the slice cap is externally initialized, the externally initialized slice is directly used here
+					if reflectValue.Cap() == 0 {
+						db.Statement.ReflectValue.Set(reflect.MakeSlice(reflectValue.Type(), 0, 20))
+					} else {
+						reflectValue.SetLen(0)
+						db.Statement.ReflectValue.Set(reflectValue)
+					}
+				}
+			}
+
+			for initialized || rows.Next() {
+			BEGIN:
+				initialized = false
+
+				if update {
+					if int(db.RowsAffected) >= reflectValue.Len() {
+						return
+					}
+					elem = reflectValue.Index(int(db.RowsAffected))
+					if onConflictDonothing {
+						for _, field := range fields {
+							if _, ok := field.ValueOf(db.Statement.Context, elem); !ok {
+								db.RowsAffected++
+								goto BEGIN
+							}
+						}
+					}
+				} else {
+					elem = reflect.New(reflectValueType)
+				}
+
+				db.scanIntoStruct(rows, elem, values, fields, joinFields)
+
+				if !update {
+					if !isPtr {
+						elem = elem.Elem()
+					}
+					if isArrayKind {
+						if reflectValue.Len() >= int(db.RowsAffected) {
+							reflectValue.Index(int(db.RowsAffected - 1)).Set(elem)
+						}
+					} else {
+						reflectValue = reflect.Append(reflectValue, elem)
+					}
+				}
+			}
+
+			if !update {
+				db.Statement.ReflectValue.Set(reflectValue)
+			}
+		case reflect.Struct, reflect.Ptr:
+			if initialized || rows.Next() {
+				if mode == ScanInitialized && reflectValue.Kind() == reflect.Struct {
+					db.Statement.ReflectValue.Set(reflect.Zero(reflectValue.Type()))
+				}
+				db.scanIntoStruct(rows, reflectValue, values, fields, joinFields)
+			}
+		default:
+			db.AddError(rows.Scan(dest))
+		}
 	}
 
-	if db.RowsAffected == 0 && db.Statement.RaiseErrorOnNotFound {
+	if err := rows.Err(); err != nil && err != db.Error {
+		db.AddError(err)
+	}
+
+	if db.RowsAffected == 0 && db.Statement.RaiseErrorOnNotFound && db.Error == nil {
 		db.AddError(ErrRecordNotFound)
 	}
 }

schema/callbacks_test.go

@@ -9,8 +9,7 @@ import (
 	"gorm.io/gorm/schema"
 )
 
-type UserWithCallback struct {
-}
+type UserWithCallback struct{}
 
 func (UserWithCallback) BeforeSave(*gorm.DB) error {
 	return nil

schema/check.go

@@ -1,37 +0,0 @@
-package schema
-
-import (
-	"regexp"
-	"strings"
-)
-
-var (
-	// reg match english letters and midline
-	regEnLetterAndMidline = regexp.MustCompile("^[A-Za-z-_]+$")
-)
-
-type Check struct {
-	Name       string
-	Constraint string // length(phone) >= 10
-	*Field
-}
-
-// ParseCheckConstraints parse schema check constraints
-func (schema *Schema) ParseCheckConstraints() map[string]Check {
-	var checks = map[string]Check{}
-	for _, field := range schema.FieldsByDBName {
-		if chk := field.TagSettings["CHECK"]; chk != "" {
-			names := strings.Split(chk, ",")
-			if len(names) > 1 && regEnLetterAndMidline.MatchString(names[0]) {
-				checks[names[0]] = Check{Name: names[0], Constraint: strings.Join(names[1:], ","), Field: field}
-			} else {
-				if names[0] == "" {
-					chk = strings.Join(names[1:], ",")
-				}
-				name := schema.namer.CheckerName(schema.Table, field.DBName)
-				checks[name] = Check{Name: name, Constraint: chk, Field: field}
-			}
-		}
-	}
-	return checks
-}

schema/constraint.go

@@ -0,0 +1,66 @@
+package schema
+
+import (
+	"regexp"
+	"strings"
+
+	"gorm.io/gorm/clause"
+)
+
+// reg match english letters and midline
+var regEnLetterAndMidline = regexp.MustCompile(`^[\w-]+$`)
+
+type CheckConstraint struct {
+	Name       string
+	Constraint string // length(phone) >= 10
+	*Field
+}
+
+func (chk *CheckConstraint) GetName() string { return chk.Name }
+
+func (chk *CheckConstraint) Build() (sql string, vars []interface{}) {
+	return "CONSTRAINT ? CHECK (?)", []interface{}{clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint}}
+}
+
+// ParseCheckConstraints parse schema check constraints
+func (schema *Schema) ParseCheckConstraints() map[string]CheckConstraint {
+	checks := map[string]CheckConstraint{}
+	for _, field := range schema.FieldsByDBName {
+		if chk := field.TagSettings["CHECK"]; chk != "" {
+			names := strings.Split(chk, ",")
+			if len(names) > 1 && regEnLetterAndMidline.MatchString(names[0]) {
+				checks[names[0]] = CheckConstraint{Name: names[0], Constraint: strings.Join(names[1:], ","), Field: field}
+			} else {
+				if names[0] == "" {
+					chk = strings.Join(names[1:], ",")
+				}
+				name := schema.namer.CheckerName(schema.Table, field.DBName)
+				checks[name] = CheckConstraint{Name: name, Constraint: chk, Field: field}
+			}
+		}
+	}
+	return checks
+}
+
+type UniqueConstraint struct {
+	Name  string
+	Field *Field
+}
+
+func (uni *UniqueConstraint) GetName() string { return uni.Name }
+
+func (uni *UniqueConstraint) Build() (sql string, vars []interface{}) {
+	return "CONSTRAINT ? UNIQUE (?)", []interface{}{clause.Column{Name: uni.Name}, clause.Column{Name: uni.Field.DBName}}
+}
+
+// ParseUniqueConstraints parse schema unique constraints
+func (schema *Schema) ParseUniqueConstraints() map[string]UniqueConstraint {
+	uniques := make(map[string]UniqueConstraint)
+	for _, field := range schema.Fields {
+		if field.Unique {
+			name := schema.namer.UniqueName(schema.Table, field.DBName)
+			uniques[name] = UniqueConstraint{Name: name, Field: field}
+		}
+	}
+	return uniques
+}

schema/constraint_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils/tests"
 )
 
 type UserCheck struct {
@@ -20,7 +21,7 @@ func TestParseCheck(t *testing.T) {
 		t.Fatalf("failed to parse user check, got error %v", err)
 	}
 
-	results := map[string]schema.Check{
+	results := map[string]schema.CheckConstraint{
 		"name_checker": {
 			Name:       "name_checker",
 			Constraint: "name <> 'jinzhu'",
@@ -53,3 +54,31 @@ func TestParseCheck(t *testing.T) {
 		}
 	}
 }
+
+func TestParseUniqueConstraints(t *testing.T) {
+	type UserUnique struct {
+		Name1 string `gorm:"unique"`
+		Name2 string `gorm:"uniqueIndex"`
+	}
+
+	user, err := schema.Parse(&UserUnique{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("failed to parse user unique, got error %v", err)
+	}
+	constraints := user.ParseUniqueConstraints()
+
+	results := map[string]schema.UniqueConstraint{
+		"uni_user_uniques_name1": {
+			Name:  "uni_user_uniques_name1",
+			Field: &schema.Field{Name: "Name1", Unique: true},
+		},
+	}
+	for k, result := range results {
+		v, ok := constraints[k]
+		if !ok {
+			t.Errorf("Failed to found unique constraint %v from parsed constraints %+v", k, constraints)
+		}
+		tests.AssertObjEqual(t, result, v, "Name")
+		tests.AssertObjEqual(t, result.Field, v.Field, "Name", "Unique", "UniqueIndex")
+	}
+}

schema/field_test.go

@@ -1,6 +1,7 @@
 package schema_test
 
 import (
+	"context"
 	"database/sql"
 	"reflect"
 	"sync"
@@ -57,7 +58,7 @@ func TestFieldValuerAndSetter(t *testing.T) {
 	}
 
 	for k, v := range newValues {
-		if err := userSchema.FieldsByDBName[k].Set(reflectValue, v); err != nil {
+		if err := userSchema.FieldsByDBName[k].Set(context.Background(), reflectValue, v); err != nil {
 			t.Errorf("no error should happen when assign value to field %v, but got %v", k, err)
 		}
 	}
@@ -80,7 +81,7 @@ func TestFieldValuerAndSetter(t *testing.T) {
 	}
 
 	for k, v := range newValues2 {
-		if err := userSchema.FieldsByDBName[k].Set(reflectValue, v); err != nil {
+		if err := userSchema.FieldsByDBName[k].Set(context.Background(), reflectValue, v); err != nil {
 			t.Errorf("no error should happen when assign value to field %v, but got %v", k, err)
 		}
 	}
@@ -132,7 +133,7 @@ func TestPointerFieldValuerAndSetter(t *testing.T) {
 	}
 
 	for k, v := range newValues {
-		if err := userSchema.FieldsByDBName[k].Set(reflectValue, v); err != nil {
+		if err := userSchema.FieldsByDBName[k].Set(context.Background(), reflectValue, v); err != nil {
 			t.Errorf("no error should happen when assign value to field %v, but got %v", k, err)
 		}
 	}
@@ -151,7 +152,7 @@ func TestPointerFieldValuerAndSetter(t *testing.T) {
 	}
 
 	for k, v := range newValues2 {
-		if err := userSchema.FieldsByDBName[k].Set(reflectValue, v); err != nil {
+		if err := userSchema.FieldsByDBName[k].Set(context.Background(), reflectValue, v); err != nil {
 			t.Errorf("no error should happen when assign value to field %v, but got %v", k, err)
 		}
 	}
@@ -202,7 +203,7 @@ func TestAdvancedDataTypeValuerAndSetter(t *testing.T) {
 	}
 
 	for k, v := range newValues {
-		if err := userSchema.FieldsByDBName[k].Set(reflectValue, v); err != nil {
+		if err := userSchema.FieldsByDBName[k].Set(context.Background(), reflectValue, v); err != nil {
 			t.Errorf("no error should happen when assign value to field %v, but got %v", k, err)
 		}
 	}
@@ -219,7 +220,7 @@ func TestAdvancedDataTypeValuerAndSetter(t *testing.T) {
 	}
 
 	for k, v := range newValues2 {
-		if err := userSchema.FieldsByDBName[k].Set(reflectValue, v); err != nil {
+		if err := userSchema.FieldsByDBName[k].Set(context.Background(), reflectValue, v); err != nil {
 			t.Errorf("no error should happen when assign value to field %v, but got %v", k, err)
 		}
 	}
@@ -235,6 +236,7 @@ type UserWithPermissionControl struct {
 	Name5 string `gorm:"<-:update"`
 	Name6 string `gorm:"<-:create,update"`
 	Name7 string `gorm:"->:false;<-:create,update"`
+	Name8 string `gorm:"->;-:migration"`
 }
 
 func TestParseFieldWithPermission(t *testing.T) {
@@ -243,7 +245,7 @@ func TestParseFieldWithPermission(t *testing.T) {
 		t.Fatalf("Failed to parse user with permission, got error %v", err)
 	}
 
-	fields := []schema.Field{
+	fields := []*schema.Field{
 		{Name: "ID", DBName: "id", BindNames: []string{"ID"}, DataType: schema.Uint, PrimaryKey: true, Size: 64, Creatable: true, Updatable: true, Readable: true, HasDefaultValue: true, AutoIncrement: true},
 		{Name: "Name", DBName: "", BindNames: []string{"Name"}, DataType: "", Tag: `gorm:"-"`, Creatable: false, Updatable: false, Readable: false},
 		{Name: "Name2", DBName: "name2", BindNames: []string{"Name2"}, DataType: schema.String, Tag: `gorm:"->"`, Creatable: false, Updatable: false, Readable: true},
@@ -252,9 +254,81 @@ func TestParseFieldWithPermission(t *testing.T) {
 		{Name: "Name5", DBName: "name5", BindNames: []string{"Name5"}, DataType: schema.String, Tag: `gorm:"<-:update"`, Creatable: false, Updatable: true, Readable: true},
 		{Name: "Name6", DBName: "name6", BindNames: []string{"Name6"}, DataType: schema.String, Tag: `gorm:"<-:create,update"`, Creatable: true, Updatable: true, Readable: true},
 		{Name: "Name7", DBName: "name7", BindNames: []string{"Name7"}, DataType: schema.String, Tag: `gorm:"->:false;<-:create,update"`, Creatable: true, Updatable: true, Readable: false},
+		{Name: "Name8", DBName: "name8", BindNames: []string{"Name8"}, DataType: schema.String, Tag: `gorm:"->;-:migration"`, Creatable: false, Updatable: false, Readable: true, IgnoreMigration: true},
 	}
 
 	for _, f := range fields {
-		checkSchemaField(t, user, &f, func(f *schema.Field) {})
+		checkSchemaField(t, user, f, func(f *schema.Field) {})
+	}
+}
+
+type (
+	ID      int64
+	INT     int
+	INT8    int8
+	INT16   int16
+	INT32   int32
+	INT64   int64
+	UINT    uint
+	UINT8   uint8
+	UINT16  uint16
+	UINT32  uint32
+	UINT64  uint64
+	FLOAT32 float32
+	FLOAT64 float64
+	BOOL    bool
+	STRING  string
+	TIME    time.Time
+	BYTES   []byte
+
+	TypeAlias struct {
+		ID
+		INT     `gorm:"column:fint"`
+		INT8    `gorm:"column:fint8"`
+		INT16   `gorm:"column:fint16"`
+		INT32   `gorm:"column:fint32"`
+		INT64   `gorm:"column:fint64"`
+		UINT    `gorm:"column:fuint"`
+		UINT8   `gorm:"column:fuint8"`
+		UINT16  `gorm:"column:fuint16"`
+		UINT32  `gorm:"column:fuint32"`
+		UINT64  `gorm:"column:fuint64"`
+		FLOAT32 `gorm:"column:ffloat32"`
+		FLOAT64 `gorm:"column:ffloat64"`
+		BOOL    `gorm:"column:fbool"`
+		STRING  `gorm:"column:fstring"`
+		TIME    `gorm:"column:ftime"`
+		BYTES   `gorm:"column:fbytes"`
+	}
+)
+
+func TestTypeAliasField(t *testing.T) {
+	alias, err := schema.Parse(&TypeAlias{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("Failed to parse TypeAlias with permission, got error %v", err)
+	}
+
+	fields := []*schema.Field{
+		{Name: "ID", DBName: "id", BindNames: []string{"ID"}, DataType: schema.Int, Creatable: true, Updatable: true, Readable: true, Size: 64, PrimaryKey: true, HasDefaultValue: true, AutoIncrement: true},
+		{Name: "INT", DBName: "fint", BindNames: []string{"INT"}, DataType: schema.Int, Creatable: true, Updatable: true, Readable: true, Size: 64, Tag: `gorm:"column:fint"`},
+		{Name: "INT8", DBName: "fint8", BindNames: []string{"INT8"}, DataType: schema.Int, Creatable: true, Updatable: true, Readable: true, Size: 8, Tag: `gorm:"column:fint8"`},
+		{Name: "INT16", DBName: "fint16", BindNames: []string{"INT16"}, DataType: schema.Int, Creatable: true, Updatable: true, Readable: true, Size: 16, Tag: `gorm:"column:fint16"`},
+		{Name: "INT32", DBName: "fint32", BindNames: []string{"INT32"}, DataType: schema.Int, Creatable: true, Updatable: true, Readable: true, Size: 32, Tag: `gorm:"column:fint32"`},
+		{Name: "INT64", DBName: "fint64", BindNames: []string{"INT64"}, DataType: schema.Int, Creatable: true, Updatable: true, Readable: true, Size: 64, Tag: `gorm:"column:fint64"`},
+		{Name: "UINT", DBName: "fuint", BindNames: []string{"UINT"}, DataType: schema.Uint, Creatable: true, Updatable: true, Readable: true, Size: 64, Tag: `gorm:"column:fuint"`},
+		{Name: "UINT8", DBName: "fuint8", BindNames: []string{"UINT8"}, DataType: schema.Uint, Creatable: true, Updatable: true, Readable: true, Size: 8, Tag: `gorm:"column:fuint8"`},
+		{Name: "UINT16", DBName: "fuint16", BindNames: []string{"UINT16"}, DataType: schema.Uint, Creatable: true, Updatable: true, Readable: true, Size: 16, Tag: `gorm:"column:fuint16"`},
+		{Name: "UINT32", DBName: "fuint32", BindNames: []string{"UINT32"}, DataType: schema.Uint, Creatable: true, Updatable: true, Readable: true, Size: 32, Tag: `gorm:"column:fuint32"`},
+		{Name: "UINT64", DBName: "fuint64", BindNames: []string{"UINT64"}, DataType: schema.Uint, Creatable: true, Updatable: true, Readable: true, Size: 64, Tag: `gorm:"column:fuint64"`},
+		{Name: "FLOAT32", DBName: "ffloat32", BindNames: []string{"FLOAT32"}, DataType: schema.Float, Creatable: true, Updatable: true, Readable: true, Size: 32, Tag: `gorm:"column:ffloat32"`},
+		{Name: "FLOAT64", DBName: "ffloat64", BindNames: []string{"FLOAT64"}, DataType: schema.Float, Creatable: true, Updatable: true, Readable: true, Size: 64, Tag: `gorm:"column:ffloat64"`},
+		{Name: "BOOL", DBName: "fbool", BindNames: []string{"BOOL"}, DataType: schema.Bool, Creatable: true, Updatable: true, Readable: true, Tag: `gorm:"column:fbool"`},
+		{Name: "STRING", DBName: "fstring", BindNames: []string{"STRING"}, DataType: schema.String, Creatable: true, Updatable: true, Readable: true, Tag: `gorm:"column:fstring"`},
+		{Name: "TIME", DBName: "ftime", BindNames: []string{"TIME"}, DataType: schema.Time, Creatable: true, Updatable: true, Readable: true, Tag: `gorm:"column:ftime"`},
+		{Name: "BYTES", DBName: "fbytes", BindNames: []string{"BYTES"}, DataType: schema.Bytes, Creatable: true, Updatable: true, Readable: true, Tag: `gorm:"column:fbytes"`},
+	}
+
+	for _, f := range fields {
+		checkSchemaField(t, alias, f, func(f *schema.Field) {})
 	}
 }

schema/index.go

@@ -1,6 +1,7 @@
 package schema
 
 import (
+	"fmt"
 	"sort"
 	"strconv"
 	"strings"
@@ -12,8 +13,8 @@ type Index struct {
 	Type    string // btree, hash, gist, spgist, gin, and brin
 	Where   string
 	Comment string
-	Option  string // WITH PARSER parser_name
-	Fields  []IndexOption
+	Option  string        // WITH PARSER parser_name
+	Fields  []IndexOption // Note: IndexOption's Field maybe the same
 }
 
 type IndexOption struct {
@@ -22,17 +23,28 @@ type IndexOption struct {
 	Sort       string // DESC, ASC
 	Collate    string
 	Length     int
-	priority   int
+	Priority   int
 }
 
 // ParseIndexes parse schema indexes
-func (schema *Schema) ParseIndexes() map[string]Index {
-	var indexes = map[string]Index{}
+func (schema *Schema) ParseIndexes() []*Index {
+	indexesByName := map[string]*Index{}
+	indexes := []*Index{}
 
 	for _, field := range schema.Fields {
 		if field.TagSettings["INDEX"] != "" || field.TagSettings["UNIQUEINDEX"] != "" {
-			for _, index := range parseFieldIndexes(field) {
-				idx := indexes[index.Name]
+			fieldIndexes, err := parseFieldIndexes(field)
+			if err != nil {
+				schema.err = err
+				break
+			}
+			for _, index := range fieldIndexes {
+				idx := indexesByName[index.Name]
+				if idx == nil {
+					idx = &Index{Name: index.Name}
+					indexesByName[index.Name] = idx
+					indexes = append(indexes, idx)
+				}
 				idx.Name = index.Name
 				if idx.Class == "" {
 					idx.Class = index.Class
@@ -52,14 +64,16 @@ func (schema *Schema) ParseIndexes() map[string]Index {
 
 				idx.Fields = append(idx.Fields, index.Fields...)
 				sort.Slice(idx.Fields, func(i, j int) bool {
-					return idx.Fields[i].priority < idx.Fields[j].priority
+					return idx.Fields[i].Priority < idx.Fields[j].Priority
 				})
-
-				indexes[index.Name] = idx
 			}
 		}
 	}
-
+	for _, index := range indexes {
+		if index.Class == "UNIQUE" && len(index.Fields) == 1 {
+			index.Fields[0].Field.UniqueIndex = index.Name
+		}
+	}
 	return indexes
 }
 
@@ -68,12 +82,12 @@ func (schema *Schema) LookIndex(name string) *Index {
 		indexes := schema.ParseIndexes()
 		for _, index := range indexes {
 			if index.Name == name {
-				return &index
+				return index
 			}
 
 			for _, field := range index.Fields {
 				if field.Name == name {
-					return &index
+					return index
 				}
 			}
 		}
@@ -82,30 +96,41 @@ func (schema *Schema) LookIndex(name string) *Index {
 	return nil
 }
 
-func parseFieldIndexes(field *Field) (indexes []Index) {
+func parseFieldIndexes(field *Field) (indexes []Index, err error) {
 	for _, value := range strings.Split(field.Tag.Get("gorm"), ";") {
 		if value != "" {
 			v := strings.Split(value, ":")
 			k := strings.TrimSpace(strings.ToUpper(v[0]))
 			if k == "INDEX" || k == "UNIQUEINDEX" {
 				var (
-					name      string
-					tag       = strings.Join(v[1:], ":")
-					idx       = strings.Index(tag, ",")
-					settings  = ParseTagSetting(tag, ",")
-					length, _ = strconv.Atoi(settings["LENGTH"])
+					name       string
+					tag        = strings.Join(v[1:], ":")
+					idx        = strings.IndexByte(tag, ',')
+					tagSetting = strings.Join(strings.Split(tag, ",")[1:], ",")
+					settings   = ParseTagSetting(tagSetting, ",")
+					length, _  = strconv.Atoi(settings["LENGTH"])
 				)
 
 				if idx == -1 {
 					idx = len(tag)
 				}
 
-				if idx != -1 {
-					name = tag[0:idx]
-				}
-
+				name = tag[0:idx]
 				if name == "" {
-					name = field.Schema.namer.IndexName(field.Schema.Table, field.Name)
+					subName := field.Name
+					const key = "COMPOSITE"
+					if composite, found := settings[key]; found {
+						if len(composite) == 0 || composite == key {
+							err = fmt.Errorf(
+								"the composite tag of %s.%s cannot be empty",
+								field.Schema.Name,
+								field.Name)
+							return
+						}
+						subName = composite
+					}
+					name = field.Schema.namer.IndexName(
+						field.Schema.Table, subName)
 				}
 
 				if (k == "UNIQUEINDEX") || settings["UNIQUE"] != "" {
@@ -130,12 +155,13 @@ func parseFieldIndexes(field *Field) (indexes []Index) {
 						Sort:       settings["SORT"],
 						Collate:    settings["COLLATE"],
 						Length:     length,
-						priority:   priority,
+						Priority:   priority,
 					}},
 				})
 			}
 		}
 	}
 
+	err = nil
 	return
 }

schema/index_test.go

@@ -1,11 +1,11 @@
 package schema_test
 
 import (
-	"reflect"
 	"sync"
 	"testing"
 
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils/tests"
 )
 
 type UserIndex struct {
@@ -18,6 +18,41 @@ type UserIndex struct {
 	Age          int64  `gorm:"index:profile,expression:ABS(age),option:WITH PARSER parser_name"`
 	OID          int64  `gorm:"index:idx_id;index:idx_oid,unique"`
 	MemberNumber string `gorm:"index:idx_id,priority:1"`
+	Name7        string `gorm:"index:type"`
+	Name8        string `gorm:"index:,length:10;index:,collate:utf8"`
+
+	CompName1 string `gorm:"index:,unique,composite:idx_compname_1,option:NULLS NOT DISTINCT;not null"`
+	CompName2 string `gorm:"index:,composite:idx_compname_1"`
+
+	// Composite Index: Flattened structure.
+	Data0A string `gorm:"index:,composite:comp_id0"`
+	Data0B string `gorm:"index:,composite:comp_id0"`
+
+	// Composite Index: Nested structure.
+	Data1A string `gorm:"index:,composite:comp_id1"`
+	CompIdxLevel1C
+
+	// Composite Index: Unique and priority.
+	Data2A string `gorm:"index:,unique,composite:comp_id2,priority:2"`
+	CompIdxLevel2C
+}
+
+type CompIdxLevel1C struct {
+	CompIdxLevel1B
+	Data1C string `gorm:"index:,composite:comp_id1"`
+}
+
+type CompIdxLevel1B struct {
+	Data1B string `gorm:"index:,composite:comp_id1"`
+}
+
+type CompIdxLevel2C struct {
+	CompIdxLevel2B
+	Data2C string `gorm:"index:,unique,composite:comp_id2,priority:1"`
+}
+
+type CompIdxLevel2B struct {
+	Data2B string `gorm:"index:,unique,composite:comp_id2,priority:3"`
 }
 
 func TestParseIndex(t *testing.T) {
@@ -26,17 +61,17 @@ func TestParseIndex(t *testing.T) {
 		t.Fatalf("failed to parse user index, got error %v", err)
 	}
 
-	results := map[string]schema.Index{
-		"idx_user_indices_name": {
+	results := []*schema.Index{
+		{
 			Name:   "idx_user_indices_name",
 			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "Name"}}},
 		},
-		"idx_name": {
+		{
 			Name:   "idx_name",
 			Class:  "UNIQUE",
-			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "Name2"}}},
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "Name2", UniqueIndex: "idx_name"}}},
 		},
-		"idx_user_indices_name3": {
+		{
 			Name:  "idx_user_indices_name3",
 			Type:  "btree",
 			Where: "name3 != 'jinzhu'",
@@ -47,19 +82,19 @@ func TestParseIndex(t *testing.T) {
 				Length:  10,
 			}},
 		},
-		"idx_user_indices_name4": {
+		{
 			Name:   "idx_user_indices_name4",
 			Class:  "UNIQUE",
-			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "Name4"}}},
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "Name4", UniqueIndex: "idx_user_indices_name4"}}},
 		},
-		"idx_user_indices_name5": {
+		{
 			Name:    "idx_user_indices_name5",
 			Class:   "FULLTEXT",
 			Comment: "hello , world",
 			Where:   "age > 10",
 			Fields:  []schema.IndexOption{{Field: &schema.Field{Name: "Name5"}}},
 		},
-		"profile": {
+		{
 			Name:    "profile",
 			Comment: "hello , world",
 			Where:   "age > 10",
@@ -69,48 +104,172 @@ func TestParseIndex(t *testing.T) {
 				Expression: "ABS(age)",
 			}},
 		},
-		"idx_id": {
+		{
 			Name:   "idx_id",
-			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "MemberNumber"}}, {Field: &schema.Field{Name: "OID"}}},
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "MemberNumber"}}, {Field: &schema.Field{Name: "OID", UniqueIndex: "idx_oid"}}},
 		},
-		"idx_oid": {
+		{
 			Name:   "idx_oid",
 			Class:  "UNIQUE",
-			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "OID"}}},
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "OID", UniqueIndex: "idx_oid"}}},
+		},
+		{
+			Name:   "type",
+			Type:   "",
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "Name7"}}},
+		},
+		{
+			Name: "idx_user_indices_name8",
+			Type: "",
+			Fields: []schema.IndexOption{
+				{Field: &schema.Field{Name: "Name8"}, Length: 10},
+				// Note: Duplicate Columns
+				{Field: &schema.Field{Name: "Name8"}, Collate: "utf8"},
+			},
+		},
+		{
+			Class:  "UNIQUE",
+			Name:   "idx_user_indices_idx_compname_1",
+			Option: "NULLS NOT DISTINCT",
+			Fields: []schema.IndexOption{
+				{Field: &schema.Field{Name: "CompName1", NotNull: true}},
+				{Field: &schema.Field{Name: "CompName2"}},
+			},
+		},
+		{
+			Name: "idx_user_indices_comp_id0",
+			Type: "",
+			Fields: []schema.IndexOption{{
+				Field: &schema.Field{Name: "Data0A"},
+			}, {
+				Field: &schema.Field{Name: "Data0B"},
+			}},
+		},
+		{
+			Name: "idx_user_indices_comp_id1",
+			Fields: []schema.IndexOption{{
+				Field: &schema.Field{Name: "Data1A"},
+			}, {
+				Field: &schema.Field{Name: "Data1B"},
+			}, {
+				Field: &schema.Field{Name: "Data1C"},
+			}},
+		},
+		{
+			Name:  "idx_user_indices_comp_id2",
+			Class: "UNIQUE",
+			Fields: []schema.IndexOption{{
+				Field: &schema.Field{Name: "Data2C"},
+			}, {
+				Field: &schema.Field{Name: "Data2A"},
+			}, {
+				Field: &schema.Field{Name: "Data2B"},
+			}},
 		},
 	}
 
-	indices := user.ParseIndexes()
+	CheckIndices(t, results, user.ParseIndexes())
+}
 
-	for k, result := range results {
-		v, ok := indices[k]
-		if !ok {
-			t.Fatalf("Failed to found index %v from parsed indices %+v", k, indices)
-		}
+func TestParseIndexWithUniqueIndexAndUnique(t *testing.T) {
+	type IndexTest struct {
+		FieldA string `gorm:"unique;index"` // unique and index
+		FieldB string `gorm:"unique"`       // unique
 
-		for _, name := range []string{"Name", "Class", "Type", "Where", "Comment", "Option"} {
-			if reflect.ValueOf(result).FieldByName(name).Interface() != reflect.ValueOf(v).FieldByName(name).Interface() {
-				t.Errorf(
-					"index %v %v should equal, expects %v, got %v",
-					k, name, reflect.ValueOf(result).FieldByName(name).Interface(), reflect.ValueOf(v).FieldByName(name).Interface(),
-				)
+		FieldC string `gorm:"index:,unique"`     // uniqueIndex
+		FieldD string `gorm:"uniqueIndex;index"` // uniqueIndex and index
+
+		FieldE1 string `gorm:"uniqueIndex:uniq_field_e1_e2"` // mul uniqueIndex
+		FieldE2 string `gorm:"uniqueIndex:uniq_field_e1_e2"`
+
+		FieldF1 string `gorm:"uniqueIndex:uniq_field_f1_f2;index"` // mul uniqueIndex and index
+		FieldF2 string `gorm:"uniqueIndex:uniq_field_f1_f2;"`
+
+		FieldG string `gorm:"unique;uniqueIndex"` // unique and uniqueIndex
+
+		FieldH1 string `gorm:"unique;uniqueIndex:uniq_field_h1_h2"` // unique and mul uniqueIndex
+		FieldH2 string `gorm:"uniqueIndex:uniq_field_h1_h2"`        // unique and mul uniqueIndex
+	}
+	indexSchema, err := schema.Parse(&IndexTest{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("failed to parse user index, got error %v", err)
+	}
+	indices := indexSchema.ParseIndexes()
+	expectedIndices := []*schema.Index{
+		{
+			Name:   "idx_index_tests_field_a",
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "FieldA", Unique: true}}},
+		},
+		{
+			Name:   "idx_index_tests_field_c",
+			Class:  "UNIQUE",
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "FieldC", UniqueIndex: "idx_index_tests_field_c"}}},
+		},
+		{
+			Name:  "idx_index_tests_field_d",
+			Class: "UNIQUE",
+			Fields: []schema.IndexOption{
+				{Field: &schema.Field{Name: "FieldD"}},
+				// Note: Duplicate Columns
+				{Field: &schema.Field{Name: "FieldD"}},
+			},
+		},
+		{
+			Name:  "uniq_field_e1_e2",
+			Class: "UNIQUE",
+			Fields: []schema.IndexOption{
+				{Field: &schema.Field{Name: "FieldE1"}},
+				{Field: &schema.Field{Name: "FieldE2"}},
+			},
+		},
+		{
+			Name:  "uniq_field_f1_f2",
+			Class: "UNIQUE",
+			Fields: []schema.IndexOption{
+				{Field: &schema.Field{Name: "FieldF1"}},
+				{Field: &schema.Field{Name: "FieldF2"}},
+			},
+		},
+		{
+			Name:   "idx_index_tests_field_f1",
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "FieldF1"}}},
+		},
+		{
+			Name:   "idx_index_tests_field_g",
+			Class:  "UNIQUE",
+			Fields: []schema.IndexOption{{Field: &schema.Field{Name: "FieldG", Unique: true, UniqueIndex: "idx_index_tests_field_g"}}},
+		},
+		{
+			Name:  "uniq_field_h1_h2",
+			Class: "UNIQUE",
+			Fields: []schema.IndexOption{
+				{Field: &schema.Field{Name: "FieldH1", Unique: true}},
+				{Field: &schema.Field{Name: "FieldH2"}},
+			},
+		},
+	}
+	CheckIndices(t, expectedIndices, indices)
+}
+
+func CheckIndices(t *testing.T, expected, actual []*schema.Index) {
+	if len(expected) != len(actual) {
+		t.Errorf("expected %d indices, but got %d", len(expected), len(actual))
+		return
+	}
+
+	for i, ei := range expected {
+		t.Run(ei.Name, func(t *testing.T) {
+			ai := actual[i]
+			tests.AssertObjEqual(t, ai, ei, "Name", "Class", "Type", "Where", "Comment", "Option")
+
+			if len(ei.Fields) != len(ai.Fields) {
+				t.Errorf("expected index %q field length is %d but actual %d", ei.Name, len(ei.Fields), len(ai.Fields))
+				return
 			}
-		}
-
-		for idx, ef := range result.Fields {
-			rf := v.Fields[idx]
-			if rf.Field.Name != ef.Field.Name {
-				t.Fatalf("index field should equal, expects %v, got %v", rf.Field.Name, ef.Field.Name)
+			for i, ef := range ei.Fields {
+				af := ai.Fields[i]
+				tests.AssertObjEqual(t, af, ef, "Name", "Unique", "UniqueIndex", "Expression", "Sort", "Collate", "Length", "NotNull")
 			}
-
-			for _, name := range []string{"Expression", "Sort", "Collate", "Length"} {
-				if reflect.ValueOf(ef).FieldByName(name).Interface() != reflect.ValueOf(rf).FieldByName(name).Interface() {
-					t.Errorf(
-						"index %v field #%v's %v should equal, expects %v, got %v", k, idx+1, name,
-						reflect.ValueOf(ef).FieldByName(name).Interface(), reflect.ValueOf(rf).FieldByName(name).Interface(),
-					)
-				}
-			}
-		}
+		})
 	}
 }

schema/interfaces.go

@@ -4,22 +4,39 @@ import (
 	"gorm.io/gorm/clause"
 )
 
+// ConstraintInterface database constraint interface
+type ConstraintInterface interface {
+	GetName() string
+	Build() (sql string, vars []interface{})
+}
+
+// GormDataTypeInterface gorm data type interface
 type GormDataTypeInterface interface {
 	GormDataType() string
 }
 
+// FieldNewValuePool field new scan value pool
+type FieldNewValuePool interface {
+	Get() interface{}
+	Put(interface{})
+}
+
+// CreateClausesInterface create clauses interface
 type CreateClausesInterface interface {
 	CreateClauses(*Field) []clause.Interface
 }
 
+// QueryClausesInterface query clauses interface
 type QueryClausesInterface interface {
 	QueryClauses(*Field) []clause.Interface
 }
 
+// UpdateClausesInterface update clauses interface
 type UpdateClausesInterface interface {
 	UpdateClauses(*Field) []clause.Interface
 }
 
+// DeleteClausesInterface delete clauses interface
 type DeleteClausesInterface interface {
 	DeleteClauses(*Field) []clause.Interface
 }

schema/model_test.go

@@ -26,9 +26,11 @@ type User struct {
 	Active    *bool
 }
 
-type mytime time.Time
-type myint int
-type mybool = bool
+type (
+	mytime time.Time
+	myint  int
+	mybool = bool
+)
 
 type AdvancedDataTypeUser struct {
 	ID           sql.NullInt64

schema/naming.go

@@ -2,21 +2,26 @@ package schema
 
 import (
 	"crypto/sha1"
-	"fmt"
+	"encoding/hex"
+	"regexp"
 	"strings"
 	"unicode/utf8"
 
 	"github.com/jinzhu/inflection"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
 )
 
 // Namer namer interface
 type Namer interface {
 	TableName(table string) string
+	SchemaName(table string) string
 	ColumnName(table, column string) string
 	JoinTableName(joinTable string) string
 	RelationshipFKName(Relationship) string
 	CheckerName(table, column string) string
 	IndexName(table, column string) string
+	UniqueName(table, column string) string
 }
 
 // Replacer replacer interface like strings.Replacer
@@ -24,12 +29,15 @@ type Replacer interface {
 	Replace(name string) string
 }
 
+var _ Namer = (*NamingStrategy)(nil)
+
 // NamingStrategy tables, columns naming strategy
 type NamingStrategy struct {
-	TablePrefix   string
-	SingularTable bool
-	NameReplacer  Replacer
-	NoLowerCase   bool
+	TablePrefix         string
+	SingularTable       bool
+	NameReplacer        Replacer
+	NoLowerCase         bool
+	IdentifierMaxLength int
 }
 
 // TableName convert string to table name
@@ -40,6 +48,16 @@ func (ns NamingStrategy) TableName(str string) string {
 	return ns.TablePrefix + inflection.Plural(ns.toDBName(str))
 }
 
+// SchemaName generate schema name from table name, don't guarantee it is the reverse value of TableName
+func (ns NamingStrategy) SchemaName(table string) string {
+	table = strings.TrimPrefix(table, ns.TablePrefix)
+
+	if ns.SingularTable {
+		return ns.toSchemaName(table)
+	}
+	return ns.toSchemaName(inflection.Singular(table))
+}
+
 // ColumnName convert string to column name
 func (ns NamingStrategy) ColumnName(table, column string) string {
 	return ns.toDBName(column)
@@ -72,17 +90,28 @@ func (ns NamingStrategy) IndexName(table, column string) string {
 	return ns.formatName("idx", table, ns.toDBName(column))
 }
 
-func (ns NamingStrategy) formatName(prefix, table, name string) string {
-	formatedName := strings.Replace(fmt.Sprintf("%v_%v_%v", prefix, table, name), ".", "_", -1)
+// UniqueName generate unique constraint name
+func (ns NamingStrategy) UniqueName(table, column string) string {
+	return ns.formatName("uni", table, ns.toDBName(column))
+}
 
-	if utf8.RuneCountInString(formatedName) > 64 {
+func (ns NamingStrategy) formatName(prefix, table, name string) string {
+	formattedName := strings.ReplaceAll(strings.Join([]string{
+		prefix, table, name,
+	}, "_"), ".", "_")
+
+	if ns.IdentifierMaxLength == 0 {
+		ns.IdentifierMaxLength = 64
+	}
+
+	if utf8.RuneCountInString(formattedName) > ns.IdentifierMaxLength {
 		h := sha1.New()
-		h.Write([]byte(formatedName))
+		h.Write([]byte(formattedName))
 		bs := h.Sum(nil)
 
-		formatedName = fmt.Sprintf("%v%v%v", prefix, table, name)[0:56] + string(bs)[:8]
+		formattedName = formattedName[0:ns.IdentifierMaxLength-8] + hex.EncodeToString(bs)[:8]
 	}
-	return formatedName
+	return formattedName
 }
 
 var (
@@ -94,7 +123,7 @@ var (
 func init() {
 	commonInitialismsForReplacer := make([]string, 0, len(commonInitialisms))
 	for _, initialism := range commonInitialisms {
-		commonInitialismsForReplacer = append(commonInitialismsForReplacer, initialism, strings.Title(strings.ToLower(initialism)))
+		commonInitialismsForReplacer = append(commonInitialismsForReplacer, initialism, cases.Title(language.Und).String(initialism))
 	}
 	commonInitialismsReplacer = strings.NewReplacer(commonInitialismsForReplacer...)
 }
@@ -105,7 +134,13 @@ func (ns NamingStrategy) toDBName(name string) string {
 	}
 
 	if ns.NameReplacer != nil {
-		name = ns.NameReplacer.Replace(name)
+		tmpName := ns.NameReplacer.Replace(name)
+
+		if tmpName == "" {
+			return name
+		}
+
+		name = tmpName
 	}
 
 	if ns.NoLowerCase {
@@ -151,3 +186,11 @@ func (ns NamingStrategy) toDBName(name string) string {
 	ret := buf.String()
 	return ret
 }
+
+func (ns NamingStrategy) toSchemaName(name string) string {
+	result := strings.ReplaceAll(cases.Title(language.Und, cases.NoLower).String(strings.ReplaceAll(name, "_", " ")), " ", "")
+	for _, initialism := range commonInitialisms {
+		result = regexp.MustCompile(cases.Title(language.Und, cases.NoLower).String(strings.ToLower(initialism))+"([A-Z]|$|_)").ReplaceAllString(result, initialism+"$1")
+	}
+	return result
+}

schema/naming_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 func TestToDBName(t *testing.T) {
-	var maps = map[string]string{
+	maps := map[string]string{
 		"":                          "",
 		"x":                         "x",
 		"X":                         "x",
@@ -33,10 +33,30 @@ func TestToDBName(t *testing.T) {
 			t.Errorf("%v toName should equal %v, but got %v", key, value, ns.toDBName(key))
 		}
 	}
+
+	maps = map[string]string{
+		"x":                              "X",
+		"user_restrictions":              "UserRestriction",
+		"this_is_a_test":                 "ThisIsATest",
+		"abc_and_jkl":                    "AbcAndJkl",
+		"employee_id":                    "EmployeeID",
+		"field_x":                        "FieldX",
+		"http_and_smtp":                  "HTTPAndSMTP",
+		"http_server_handler_for_url_id": "HTTPServerHandlerForURLID",
+		"uuid":                           "UUID",
+		"http_url":                       "HTTPURL",
+		"sha256_hash":                    "Sha256Hash",
+		"this_is_actually_a_test_so_we_may_be_able_to_use_this_code_in_gorm_package_also_id_can_be_used_at_the_end_as_id": "ThisIsActuallyATestSoWeMayBeAbleToUseThisCodeInGormPackageAlsoIDCanBeUsedAtTheEndAsID",
+	}
+	for key, value := range maps {
+		if ns.SchemaName(key) != value {
+			t.Errorf("%v schema name should equal %v, but got %v", key, value, ns.SchemaName(key))
+		}
+	}
 }
 
 func TestNamingStrategy(t *testing.T) {
-	var ns = NamingStrategy{
+	ns := NamingStrategy{
 		TablePrefix:   "public.",
 		SingularTable: true,
 		NameReplacer:  strings.NewReplacer("CID", "Cid"),
@@ -82,7 +102,7 @@ func (r CustomReplacer) Replace(name string) string {
 }
 
 func TestCustomReplacer(t *testing.T) {
-	var ns = NamingStrategy{
+	ns := NamingStrategy{
 		TablePrefix:   "public.",
 		SingularTable: true,
 		NameReplacer: CustomReplacer{
@@ -126,7 +146,7 @@ func TestCustomReplacer(t *testing.T) {
 }
 
 func TestCustomReplacerWithNoLowerCase(t *testing.T) {
-	var ns = NamingStrategy{
+	ns := NamingStrategy{
 		TablePrefix:   "public.",
 		SingularTable: true,
 		NameReplacer: CustomReplacer{
@@ -168,3 +188,32 @@ func TestCustomReplacerWithNoLowerCase(t *testing.T) {
 		t.Errorf("invalid column name generated, got %v", columdName)
 	}
 }
+
+func TestFormatNameWithStringLongerThan63Characters(t *testing.T) {
+	ns := NamingStrategy{IdentifierMaxLength: 63}
+
+	formattedName := ns.formatName("prefix", "table", "thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVeryLongString")
+	if formattedName != "prefix_table_thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVer180f2c67" {
+		t.Errorf("invalid formatted name generated, got %v", formattedName)
+	}
+}
+
+func TestFormatNameWithStringLongerThan64Characters(t *testing.T) {
+	ns := NamingStrategy{IdentifierMaxLength: 64}
+
+	formattedName := ns.formatName("prefix", "table", "thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVeryLongString")
+	if formattedName != "prefix_table_thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVery180f2c67" {
+		t.Errorf("invalid formatted name generated, got %v", formattedName)
+	}
+}
+
+func TestReplaceEmptyTableName(t *testing.T) {
+	ns := NamingStrategy{
+		SingularTable: true,
+		NameReplacer:  strings.NewReplacer("Model", ""),
+	}
+	tableName := ns.TableName("Model")
+	if tableName != "Model" {
+		t.Errorf("invalid table name generated, got %v", tableName)
+	}
+}

schema/pool.go

@@ -0,0 +1,19 @@
+package schema
+
+import (
+	"reflect"
+	"sync"
+)
+
+// sync pools
+var (
+	normalPool      sync.Map
+	poolInitializer = func(reflectType reflect.Type) FieldNewValuePool {
+		v, _ := normalPool.LoadOrStore(reflectType, &sync.Pool{
+			New: func() interface{} {
+				return reflect.New(reflectType).Interface()
+			},
+		})
+		return v.(FieldNewValuePool)
+	}
+)

schema/relationship.go

@@ -1,11 +1,16 @@
 package schema
 
 import (
+	"context"
 	"fmt"
 	"reflect"
 	"strings"
+	"sync"
 
 	"github.com/jinzhu/inflection"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
+
 	"gorm.io/gorm/clause"
 )
 
@@ -26,6 +31,10 @@ type Relationships struct {
 	HasMany   []*Relationship
 	Many2Many []*Relationship
 	Relations map[string]*Relationship
+
+	EmbeddedRelations map[string]*Relationships
+
+	Mux sync.RWMutex
 }
 
 type Relationship struct {
@@ -69,14 +78,16 @@ func (schema *Schema) parseRelation(field *Field) *Relationship {
 	cacheStore := schema.cacheStore
 
 	if relation.FieldSchema, err = getOrParse(fieldValue, cacheStore, schema.namer); err != nil {
-		schema.err = err
+		schema.err = fmt.Errorf("failed to parse field: %s, error: %w", field.Name, err)
 		return nil
 	}
 
-	if polymorphic := field.TagSettings["POLYMORPHIC"]; polymorphic != "" {
-		schema.buildPolymorphicRelation(relation, field, polymorphic)
+	if hasPolymorphicRelation(field.TagSettings) {
+		schema.buildPolymorphicRelation(relation, field)
 	} else if many2many := field.TagSettings["MANY2MANY"]; many2many != "" {
 		schema.buildMany2ManyRelation(relation, field, many2many)
+	} else if belongsTo := field.TagSettings["BELONGSTO"]; belongsTo != "" {
+		schema.guessRelation(relation, field, guessBelongs)
 	} else {
 		switch field.IndirectFieldType.Kind() {
 		case reflect.Struct:
@@ -84,14 +95,16 @@ func (schema *Schema) parseRelation(field *Field) *Relationship {
 		case reflect.Slice:
 			schema.guessRelation(relation, field, guessHas)
 		default:
-			schema.err = fmt.Errorf("unsupported data type %v for %v on field %v", relation.FieldSchema, schema, field.Name)
+			schema.err = fmt.Errorf("unsupported data type %v for %v on field %s", relation.FieldSchema, schema,
+				field.Name)
 		}
 	}
 
 	if relation.Type == has {
-		// don't add relations to embeded schema, which might be shared
 		if relation.FieldSchema != relation.Schema && relation.Polymorphic == nil && field.OwnerSchema == nil {
+			relation.FieldSchema.Relationships.Mux.Lock()
 			relation.FieldSchema.Relationships.Relations["_"+relation.Schema.Name+"_"+relation.Name] = relation
+			relation.FieldSchema.Relationships.Mux.Unlock()
 		}
 
 		switch field.IndirectFieldType.Kind() {
@@ -103,7 +116,7 @@ func (schema *Schema) parseRelation(field *Field) *Relationship {
 	}
 
 	if schema.err == nil {
-		schema.Relationships.Relations[relation.Name] = relation
+		schema.setRelation(relation)
 		switch relation.Type {
 		case HasOne:
 			schema.Relationships.HasOne = append(schema.Relationships.HasOne, relation)
@@ -119,34 +132,100 @@ func (schema *Schema) parseRelation(field *Field) *Relationship {
 	return relation
 }
 
-// User has many Toys, its `Polymorphic` is `Owner`, Pet has one Toy, its `Polymorphic` is `Owner`
-//     type User struct {
-//       Toys []Toy `gorm:"polymorphic:Owner;"`
-//     }
-//     type Pet struct {
-//       Toy Toy `gorm:"polymorphic:Owner;"`
-//     }
-//     type Toy struct {
-//       OwnerID   int
-//       OwnerType string
-//     }
-func (schema *Schema) buildPolymorphicRelation(relation *Relationship, field *Field, polymorphic string) {
-	relation.Polymorphic = &Polymorphic{
-		Value:           schema.Table,
-		PolymorphicType: relation.FieldSchema.FieldsByName[polymorphic+"Type"],
-		PolymorphicID:   relation.FieldSchema.FieldsByName[polymorphic+"ID"],
+// hasPolymorphicRelation check if has polymorphic relation
+// 1. `POLYMORPHIC` tag
+// 2. `POLYMORPHICTYPE` and `POLYMORPHICID` tag
+func hasPolymorphicRelation(tagSettings map[string]string) bool {
+	if _, ok := tagSettings["POLYMORPHIC"]; ok {
+		return true
 	}
 
+	_, hasType := tagSettings["POLYMORPHICTYPE"]
+	_, hasId := tagSettings["POLYMORPHICID"]
+
+	return hasType && hasId
+}
+
+func (schema *Schema) setRelation(relation *Relationship) {
+	// set non-embedded relation
+	if rel := schema.Relationships.Relations[relation.Name]; rel != nil {
+		if len(rel.Field.BindNames) > 1 {
+			schema.Relationships.Relations[relation.Name] = relation
+		}
+	} else {
+		schema.Relationships.Relations[relation.Name] = relation
+	}
+
+	// set embedded relation
+	if len(relation.Field.EmbeddedBindNames) <= 1 {
+		return
+	}
+	relationships := &schema.Relationships
+	for i, name := range relation.Field.EmbeddedBindNames {
+		if i < len(relation.Field.EmbeddedBindNames)-1 {
+			if relationships.EmbeddedRelations == nil {
+				relationships.EmbeddedRelations = map[string]*Relationships{}
+			}
+			if r := relationships.EmbeddedRelations[name]; r == nil {
+				relationships.EmbeddedRelations[name] = &Relationships{}
+			}
+			relationships = relationships.EmbeddedRelations[name]
+		} else {
+			if relationships.Relations == nil {
+				relationships.Relations = map[string]*Relationship{}
+			}
+			relationships.Relations[relation.Name] = relation
+		}
+	}
+}
+
+// User has many Toys, its `Polymorphic` is `Owner`, Pet has one Toy, its `Polymorphic` is `Owner`
+//
+//	type User struct {
+//	  Toys []Toy `gorm:"polymorphic:Owner;"`
+//	}
+//	type Pet struct {
+//	  Toy Toy `gorm:"polymorphic:Owner;"`
+//	}
+//	type Toy struct {
+//	  OwnerID   int
+//	  OwnerType string
+//	}
+func (schema *Schema) buildPolymorphicRelation(relation *Relationship, field *Field) {
+	polymorphic := field.TagSettings["POLYMORPHIC"]
+
+	relation.Polymorphic = &Polymorphic{
+		Value: schema.Table,
+	}
+
+	var (
+		typeName = polymorphic + "Type"
+		typeId   = polymorphic + "ID"
+	)
+
+	if value, ok := field.TagSettings["POLYMORPHICTYPE"]; ok {
+		typeName = strings.TrimSpace(value)
+	}
+
+	if value, ok := field.TagSettings["POLYMORPHICID"]; ok {
+		typeId = strings.TrimSpace(value)
+	}
+
+	relation.Polymorphic.PolymorphicType = relation.FieldSchema.FieldsByName[typeName]
+	relation.Polymorphic.PolymorphicID = relation.FieldSchema.FieldsByName[typeId]
+
 	if value, ok := field.TagSettings["POLYMORPHICVALUE"]; ok {
 		relation.Polymorphic.Value = strings.TrimSpace(value)
 	}
 
 	if relation.Polymorphic.PolymorphicType == nil {
-		schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %v, missing field %v", relation.FieldSchema, schema, field.Name, polymorphic+"Type")
+		schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %s, missing field %s",
+			relation.FieldSchema, schema, field.Name, polymorphic+"Type")
 	}
 
 	if relation.Polymorphic.PolymorphicID == nil {
-		schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %v, missing field %v", relation.FieldSchema, schema, field.Name, polymorphic+"ID")
+		schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %s, missing field %s",
+			relation.FieldSchema, schema, field.Name, polymorphic+"ID")
 	}
 
 	if schema.err == nil {
@@ -158,12 +237,21 @@ func (schema *Schema) buildPolymorphicRelation(relation *Relationship, field *Fi
 		primaryKeyField := schema.PrioritizedPrimaryField
 		if len(relation.foreignKeys) > 0 {
 			if primaryKeyField = schema.LookUpField(relation.foreignKeys[0]); primaryKeyField == nil || len(relation.foreignKeys) > 1 {
-				schema.err = fmt.Errorf("invalid polymorphic foreign keys %+v for %v on field %v", relation.foreignKeys, schema, field.Name)
+				schema.err = fmt.Errorf("invalid polymorphic foreign keys %+v for %v on field %s", relation.foreignKeys,
+					schema, field.Name)
 			}
 		}
 
+		if primaryKeyField == nil {
+			schema.err = fmt.Errorf("invalid polymorphic type %v for %v on field %s, missing primaryKey field",
+				relation.FieldSchema, schema, field.Name)
+			return
+		}
+
 		// use same data type for foreign keys
-		relation.Polymorphic.PolymorphicID.DataType = primaryKeyField.DataType
+		if copyableDataType(primaryKeyField.DataType) {
+			relation.Polymorphic.PolymorphicID.DataType = primaryKeyField.DataType
+		}
 		relation.Polymorphic.PolymorphicID.GORMDataType = primaryKeyField.GORMDataType
 		if relation.Polymorphic.PolymorphicID.Size == 0 {
 			relation.Polymorphic.PolymorphicID.Size = primaryKeyField.Size
@@ -186,7 +274,8 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 		err             error
 		joinTableFields []reflect.StructField
 		fieldsMap       = map[string]*Field{}
-		ownFieldsMap    = map[string]bool{} // fix self join many2many
+		ownFieldsMap    = map[string]*Field{} // fix self join many2many
+		referFieldsMap  = map[string]*Field{}
 		joinForeignKeys = toColumns(field.TagSettings["JOINFOREIGNKEY"])
 		joinReferences  = toColumns(field.TagSettings["JOINREFERENCES"])
 	)
@@ -200,7 +289,7 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 			if field := schema.LookUpField(foreignKey); field != nil {
 				ownForeignFields = append(ownForeignFields, field)
 			} else {
-				schema.err = fmt.Errorf("invalid foreign key: %v", foreignKey)
+				schema.err = fmt.Errorf("invalid foreign key: %s", foreignKey)
 				return
 			}
 		}
@@ -212,33 +301,31 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 			if field := relation.FieldSchema.LookUpField(foreignKey); field != nil {
 				refForeignFields = append(refForeignFields, field)
 			} else {
-				schema.err = fmt.Errorf("invalid foreign key: %v", foreignKey)
+				schema.err = fmt.Errorf("invalid foreign key: %s", foreignKey)
 				return
 			}
 		}
 	}
 
 	for idx, ownField := range ownForeignFields {
-		joinFieldName := strings.Title(schema.Name) + ownField.Name
+		joinFieldName := cases.Title(language.Und, cases.NoLower).String(schema.Name) + ownField.Name
 		if len(joinForeignKeys) > idx {
-			joinFieldName = strings.Title(joinForeignKeys[idx])
+			joinFieldName = cases.Title(language.Und, cases.NoLower).String(joinForeignKeys[idx])
 		}
 
-		ownFieldsMap[joinFieldName] = true
+		ownFieldsMap[joinFieldName] = ownField
 		fieldsMap[joinFieldName] = ownField
 		joinTableFields = append(joinTableFields, reflect.StructField{
 			Name:    joinFieldName,
 			PkgPath: ownField.StructField.PkgPath,
 			Type:    ownField.StructField.Type,
-			Tag:     removeSettingFromTag(ownField.StructField.Tag, "column", "autoincrement", "index", "unique", "uniqueindex"),
+			Tag: removeSettingFromTag(appendSettingFromTag(ownField.StructField.Tag, "primaryKey"),
+				"column", "autoincrement", "index", "unique", "uniqueindex"),
 		})
 	}
 
 	for idx, relField := range refForeignFields {
-		joinFieldName := relation.FieldSchema.Name + relField.Name
-		if len(joinReferences) > idx {
-			joinFieldName = strings.Title(joinReferences[idx])
-		}
+		joinFieldName := cases.Title(language.Und, cases.NoLower).String(relation.FieldSchema.Name) + relField.Name
 
 		if _, ok := ownFieldsMap[joinFieldName]; ok {
 			if field.Name != relation.FieldSchema.Name {
@@ -248,22 +335,32 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 			}
 		}
 
-		fieldsMap[joinFieldName] = relField
-		joinTableFields = append(joinTableFields, reflect.StructField{
-			Name:    joinFieldName,
-			PkgPath: relField.StructField.PkgPath,
-			Type:    relField.StructField.Type,
-			Tag:     removeSettingFromTag(relField.StructField.Tag, "column", "autoincrement", "index", "unique", "uniqueindex"),
-		})
+		if len(joinReferences) > idx {
+			joinFieldName = cases.Title(language.Und, cases.NoLower).String(joinReferences[idx])
+		}
+
+		referFieldsMap[joinFieldName] = relField
+
+		if _, ok := fieldsMap[joinFieldName]; !ok {
+			fieldsMap[joinFieldName] = relField
+			joinTableFields = append(joinTableFields, reflect.StructField{
+				Name:    joinFieldName,
+				PkgPath: relField.StructField.PkgPath,
+				Type:    relField.StructField.Type,
+				Tag: removeSettingFromTag(appendSettingFromTag(relField.StructField.Tag, "primaryKey"),
+					"column", "autoincrement", "index", "unique", "uniqueindex"),
+			})
+		}
 	}
 
 	joinTableFields = append(joinTableFields, reflect.StructField{
-		Name: strings.Title(schema.Name) + field.Name,
+		Name: cases.Title(language.Und, cases.NoLower).String(schema.Name) + field.Name,
 		Type: schema.ModelType,
 		Tag:  `gorm:"-"`,
 	})
 
-	if relation.JoinTable, err = Parse(reflect.New(reflect.StructOf(joinTableFields)).Interface(), schema.cacheStore, schema.namer); err != nil {
+	if relation.JoinTable, err = Parse(reflect.New(reflect.StructOf(joinTableFields)).Interface(), schema.cacheStore,
+		schema.namer); err != nil {
 		schema.err = err
 	}
 	relation.JoinTable.Name = many2many
@@ -302,37 +399,45 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 	for _, f := range relation.JoinTable.Fields {
 		if f.Creatable || f.Readable || f.Updatable {
 			// use same data type for foreign keys
-			f.DataType = fieldsMap[f.Name].DataType
+			if copyableDataType(fieldsMap[f.Name].DataType) {
+				f.DataType = fieldsMap[f.Name].DataType
+			}
 			f.GORMDataType = fieldsMap[f.Name].GORMDataType
 			if f.Size == 0 {
 				f.Size = fieldsMap[f.Name].Size
 			}
 			relation.JoinTable.PrimaryFields = append(relation.JoinTable.PrimaryFields, f)
-			ownPriamryField := schema == fieldsMap[f.Name].Schema && ownFieldsMap[f.Name]
 
-			if ownPriamryField {
+			if of, ok := ownFieldsMap[f.Name]; ok {
 				joinRel := relation.JoinTable.Relationships.Relations[relName]
 				joinRel.Field = relation.Field
 				joinRel.References = append(joinRel.References, &Reference{
-					PrimaryKey: fieldsMap[f.Name],
+					PrimaryKey: of,
 					ForeignKey: f,
 				})
-			} else {
+
+				relation.References = append(relation.References, &Reference{
+					PrimaryKey:    of,
+					ForeignKey:    f,
+					OwnPrimaryKey: true,
+				})
+			}
+
+			if rf, ok := referFieldsMap[f.Name]; ok {
 				joinRefRel := relation.JoinTable.Relationships.Relations[relRefName]
 				if joinRefRel.Field == nil {
 					joinRefRel.Field = relation.Field
 				}
 				joinRefRel.References = append(joinRefRel.References, &Reference{
-					PrimaryKey: fieldsMap[f.Name],
+					PrimaryKey: rf,
+					ForeignKey: f,
+				})
+
+				relation.References = append(relation.References, &Reference{
+					PrimaryKey: rf,
 					ForeignKey: f,
 				})
 			}
-
-			relation.References = append(relation.References, &Reference{
-				PrimaryKey:    fieldsMap[f.Name],
-				ForeignKey:    f,
-				OwnPrimaryKey: ownPriamryField,
-			})
 		}
 	}
 }
@@ -374,7 +479,8 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 			schema.guessRelation(relation, field, guessEmbeddedHas)
 		// case guessEmbeddedHas:
 		default:
-			schema.err = fmt.Errorf("invalid field found for struct %v's field %v, need to define a valid foreign key for relations or it need to implement the Valuer/Scanner interface", schema, field.Name)
+			schema.err = fmt.Errorf("invalid field found for struct %v's field %s: define a valid foreign key for relations or implement the Valuer/Scanner interface",
+				schema, field.Name)
 		}
 	}
 
@@ -382,33 +488,34 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 	case guessBelongs:
 		primarySchema, foreignSchema = relation.FieldSchema, schema
 	case guessEmbeddedBelongs:
-		if field.OwnerSchema != nil {
-			primarySchema, foreignSchema = relation.FieldSchema, field.OwnerSchema
-		} else {
+		if field.OwnerSchema == nil {
 			reguessOrErr()
 			return
 		}
+		primarySchema, foreignSchema = relation.FieldSchema, field.OwnerSchema
 	case guessHas:
 	case guessEmbeddedHas:
-		if field.OwnerSchema != nil {
-			primarySchema, foreignSchema = field.OwnerSchema, relation.FieldSchema
-		} else {
+		if field.OwnerSchema == nil {
 			reguessOrErr()
 			return
 		}
+		primarySchema, foreignSchema = field.OwnerSchema, relation.FieldSchema
 	}
 
 	if len(relation.foreignKeys) > 0 {
 		for _, foreignKey := range relation.foreignKeys {
-			if f := foreignSchema.LookUpField(foreignKey); f != nil {
-				foreignFields = append(foreignFields, f)
-			} else {
+			f := foreignSchema.LookUpField(foreignKey)
+			if f == nil {
 				reguessOrErr()
 				return
 			}
+			foreignFields = append(foreignFields, f)
 		}
 	} else {
-		var primaryFields []*Field
+		primarySchemaName := primarySchema.Name
+		if primarySchemaName == "" {
+			primarySchemaName = relation.FieldSchema.Name
+		}
 
 		if len(relation.primaryKeys) > 0 {
 			for _, primaryKey := range relation.primaryKeys {
@@ -420,31 +527,42 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 			primaryFields = primarySchema.PrimaryFields
 		}
 
+	primaryFieldLoop:
 		for _, primaryField := range primaryFields {
-			lookUpName := primarySchema.Name + primaryField.Name
+			lookUpName := primarySchemaName + primaryField.Name
 			if gl == guessBelongs {
 				lookUpName = field.Name + primaryField.Name
 			}
 
 			lookUpNames := []string{lookUpName}
 			if len(primaryFields) == 1 {
-				lookUpNames = append(lookUpNames, strings.TrimSuffix(lookUpName, primaryField.Name)+"ID", strings.TrimSuffix(lookUpName, primaryField.Name)+"Id", schema.namer.ColumnName(foreignSchema.Table, strings.TrimSuffix(lookUpName, primaryField.Name)+"ID"))
+				lookUpNames = append(lookUpNames, strings.TrimSuffix(lookUpName, primaryField.Name)+"ID",
+					strings.TrimSuffix(lookUpName, primaryField.Name)+"Id", schema.namer.ColumnName(foreignSchema.Table,
+						strings.TrimSuffix(lookUpName, primaryField.Name)+"ID"))
 			}
 
+			for _, name := range lookUpNames {
+				if f := foreignSchema.LookUpFieldByBindName(field.BindNames, name); f != nil {
+					foreignFields = append(foreignFields, f)
+					primaryFields = append(primaryFields, primaryField)
+					continue primaryFieldLoop
+				}
+			}
 			for _, name := range lookUpNames {
 				if f := foreignSchema.LookUpField(name); f != nil {
 					foreignFields = append(foreignFields, f)
 					primaryFields = append(primaryFields, primaryField)
-					break
+					continue primaryFieldLoop
 				}
 			}
 		}
 	}
 
-	if len(foreignFields) == 0 {
+	switch {
+	case len(foreignFields) == 0:
 		reguessOrErr()
 		return
-	} else if len(relation.primaryKeys) > 0 {
+	case len(relation.primaryKeys) > 0:
 		for idx, primaryKey := range relation.primaryKeys {
 			if f := primarySchema.LookUpField(primaryKey); f != nil {
 				if len(primaryFields) < idx+1 {
@@ -458,7 +576,7 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 				return
 			}
 		}
-	} else if len(primaryFields) == 0 {
+	case len(primaryFields) == 0:
 		if len(foreignFields) == 1 && primarySchema.PrioritizedPrimaryField != nil {
 			primaryFields = append(primaryFields, primarySchema.PrioritizedPrimaryField)
 		} else if len(primarySchema.PrimaryFields) == len(foreignFields) {
@@ -472,7 +590,9 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 	// build references
 	for idx, foreignField := range foreignFields {
 		// use same data type for foreign keys
-		foreignField.DataType = primaryFields[idx].DataType
+		if copyableDataType(primaryFields[idx].DataType) {
+			foreignField.DataType = primaryFields[idx].DataType
+		}
 		foreignField.GORMDataType = primaryFields[idx].GORMDataType
 		if foreignField.Size == 0 {
 			foreignField.Size = primaryFields[idx].Size
@@ -492,6 +612,7 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 	}
 }
 
+// Constraint is ForeignKey Constraint
 type Constraint struct {
 	Name            string
 	Field           *Field
@@ -503,6 +624,31 @@ type Constraint struct {
 	OnUpdate        string
 }
 
+func (constraint *Constraint) GetName() string { return constraint.Name }
+
+func (constraint *Constraint) Build() (sql string, vars []interface{}) {
+	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
+	if constraint.OnDelete != "" {
+		sql += " ON DELETE " + constraint.OnDelete
+	}
+
+	if constraint.OnUpdate != "" {
+		sql += " ON UPDATE " + constraint.OnUpdate
+	}
+
+	foreignKeys := make([]interface{}, 0, len(constraint.ForeignKeys))
+	for _, field := range constraint.ForeignKeys {
+		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})
+	}
+
+	references := make([]interface{}, 0, len(constraint.References))
+	for _, field := range constraint.References {
+		references = append(references, clause.Column{Name: field.DBName})
+	}
+	vars = append(vars, clause.Table{Name: constraint.Name}, foreignKeys, clause.Table{Name: constraint.ReferenceSchema.Table}, references)
+	return
+}
+
 func (rel *Relationship) ParseConstraint() *Constraint {
 	str := rel.Field.TagSettings["CONSTRAINT"]
 	if str == "-" {
@@ -511,12 +657,13 @@ func (rel *Relationship) ParseConstraint() *Constraint {
 
 	if rel.Type == BelongsTo {
 		for _, r := range rel.FieldSchema.Relationships.Relations {
-			if r.FieldSchema == rel.Schema && len(rel.References) == len(r.References) {
+			if r != rel && r.FieldSchema == rel.Schema && len(rel.References) == len(r.References) {
 				matched := true
 				for idx, ref := range r.References {
 					if !(rel.References[idx].PrimaryKey == ref.PrimaryKey && rel.References[idx].ForeignKey == ref.ForeignKey &&
 						rel.References[idx].PrimaryValue == ref.PrimaryValue) {
 						matched = false
+						break
 					}
 				}
 
@@ -529,7 +676,7 @@ func (rel *Relationship) ParseConstraint() *Constraint {
 
 	var (
 		name     string
-		idx      = strings.Index(str, ",")
+		idx      = strings.IndexByte(str, ',')
 		settings = ParseTagSetting(str, ",")
 	)
 
@@ -568,7 +715,7 @@ func (rel *Relationship) ParseConstraint() *Constraint {
 	return &constraint
 }
 
-func (rel *Relationship) ToQueryConditions(reflectValue reflect.Value) (conds []clause.Expression) {
+func (rel *Relationship) ToQueryConditions(ctx context.Context, reflectValue reflect.Value) (conds []clause.Expression) {
 	table := rel.FieldSchema.Table
 	foreignFields := []*Field{}
 	relForeignKeys := []string{}
@@ -608,9 +755,19 @@ func (rel *Relationship) ToQueryConditions(reflectValue reflect.Value) (conds []
 		}
 	}
 
-	_, foreignValues := GetIdentityFieldValuesMap(reflectValue, foreignFields)
+	_, foreignValues := GetIdentityFieldValuesMap(ctx, reflectValue, foreignFields)
 	column, values := ToQueryValues(table, relForeignKeys, foreignValues)
 
 	conds = append(conds, clause.IN{Column: column, Values: values})
 	return
 }
+
+func copyableDataType(str DataType) bool {
+	lowerStr := strings.ToLower(string(str))
+	for _, s := range []string{"auto_increment", "primary key"} {
+		if strings.Contains(lowerStr, s) {
+			return false
+		}
+	}
+	return true
+}

schema/relationship_test.go

@@ -10,7 +10,7 @@ import (
 
 func checkStructRelation(t *testing.T, data interface{}, relations ...Relation) {
 	if s, err := schema.Parse(data, &sync.Map{}, schema.NamingStrategy{}); err != nil {
-		t.Errorf("Failed to parse schema")
+		t.Errorf("Failed to parse schema, got error %v", err)
 	} else {
 		for _, rel := range relations {
 			checkSchemaRelation(t, s, rel)
@@ -93,6 +93,20 @@ func TestBelongsToWithOnlyReferences2(t *testing.T) {
 	})
 }
 
+func TestSelfReferentialBelongsTo(t *testing.T) {
+	type User struct {
+		ID        int32 `gorm:"primaryKey"`
+		Name      string
+		CreatorID *int32
+		Creator   *User
+	}
+
+	checkStructRelation(t, &User{}, Relation{
+		Name: "Creator", Type: schema.BelongsTo, Schema: "User", FieldSchema: "User",
+		References: []Reference{{"ID", "User", "CreatorID", "User", "", false}},
+	})
+}
+
 func TestSelfReferentialBelongsToOverrideReferences(t *testing.T) {
 	type User struct {
 		ID        int32 `gorm:"primaryKey"`
@@ -107,6 +121,29 @@ func TestSelfReferentialBelongsToOverrideReferences(t *testing.T) {
 	})
 }
 
+func TestBelongsToWithMixin(t *testing.T) {
+	type Profile struct {
+		gorm.Model
+		Refer string
+		Name  string
+	}
+
+	type ProfileMixin struct {
+		Profile      Profile `gorm:"References:Refer"`
+		ProfileRefer int
+	}
+
+	type User struct {
+		gorm.Model
+		ProfileMixin
+	}
+
+	checkStructRelation(t, &User{}, Relation{
+		Name: "Profile", Type: schema.BelongsTo, Schema: "User", FieldSchema: "Profile",
+		References: []Reference{{"Refer", "Profile", "ProfileRefer", "User", "", false}},
+	})
+}
+
 func TestHasOneOverrideForeignKey(t *testing.T) {
 	type Profile struct {
 		gorm.Model
@@ -144,6 +181,24 @@ func TestHasOneOverrideReferences(t *testing.T) {
 	})
 }
 
+func TestHasOneOverrideReferences2(t *testing.T) {
+	type Profile struct {
+		gorm.Model
+		Name string
+	}
+
+	type User struct {
+		gorm.Model
+		ProfileID uint     `gorm:"column:profile_id"`
+		Profile   *Profile `gorm:"foreignKey:ID;references:ProfileID"`
+	}
+
+	checkStructRelation(t, &User{}, Relation{
+		Name: "Profile", Type: schema.HasOne, Schema: "User", FieldSchema: "Profile",
+		References: []Reference{{"ProfileID", "User", "ID", "Profile", "", true}},
+	})
+}
+
 func TestHasOneWithOnlyReferences(t *testing.T) {
 	type Profile struct {
 		gorm.Model
@@ -273,6 +328,33 @@ func TestMany2ManyOverrideForeignKey(t *testing.T) {
 	})
 }
 
+func TestMany2ManySharedForeignKey(t *testing.T) {
+	type Profile struct {
+		gorm.Model
+		Name         string
+		Kind         string
+		ProfileRefer uint
+	}
+
+	type User struct {
+		gorm.Model
+		Profiles []Profile `gorm:"many2many:user_profiles;foreignKey:Refer,Kind;joinForeignKey:UserRefer,Kind;References:ProfileRefer,Kind;joinReferences:ProfileR,Kind"`
+		Kind     string
+		Refer    uint
+	}
+
+	checkStructRelation(t, &User{}, Relation{
+		Name: "Profiles", Type: schema.Many2Many, Schema: "User", FieldSchema: "Profile",
+		JoinTable: JoinTable{Name: "user_profiles", Table: "user_profiles"},
+		References: []Reference{
+			{"Refer", "User", "UserRefer", "user_profiles", "", true},
+			{"Kind", "User", "Kind", "user_profiles", "", true},
+			{"ProfileRefer", "Profile", "ProfileR", "user_profiles", "", false},
+			{"Kind", "Profile", "Kind", "user_profiles", "", false},
+		},
+	})
+}
+
 func TestMany2ManyOverrideJoinForeignKey(t *testing.T) {
 	type Profile struct {
 		gorm.Model
@@ -459,6 +541,340 @@ func TestEmbeddedRelation(t *testing.T) {
 	}
 }
 
+func TestEmbeddedHas(t *testing.T) {
+	type Toy struct {
+		ID        int
+		Name      string
+		OwnerID   int
+		OwnerType string
+	}
+	type User struct {
+		ID  int
+		Cat struct {
+			Name string
+			Toy  Toy   `gorm:"polymorphic:Owner;"`
+			Toys []Toy `gorm:"polymorphic:Owner;"`
+		} `gorm:"embedded;embeddedPrefix:cat_"`
+		Dog struct {
+			ID     int
+			Name   string
+			UserID int
+			Toy    Toy   `gorm:"polymorphic:Owner;"`
+			Toys   []Toy `gorm:"polymorphic:Owner;"`
+		}
+		Toys []Toy `gorm:"polymorphic:Owner;"`
+	}
+
+	s, err := schema.Parse(&User{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("Failed to parse schema, got error %v", err)
+	}
+
+	checkEmbeddedRelations(t, s.Relationships.EmbeddedRelations, map[string]EmbeddedRelations{
+		"Cat": {
+			Relations: map[string]Relation{
+				"Toy": {
+					Name:        "Toy",
+					Type:        schema.HasOne,
+					Schema:      "User",
+					FieldSchema: "Toy",
+					Polymorphic: Polymorphic{ID: "OwnerID", Type: "OwnerType", Value: "users"},
+					References: []Reference{
+						{ForeignKey: "OwnerType", ForeignSchema: "Toy", PrimaryValue: "users"},
+						{ForeignKey: "OwnerType", ForeignSchema: "Toy", PrimaryValue: "users"},
+					},
+				},
+				"Toys": {
+					Name:        "Toys",
+					Type:        schema.HasMany,
+					Schema:      "User",
+					FieldSchema: "Toy",
+					Polymorphic: Polymorphic{ID: "OwnerID", Type: "OwnerType", Value: "users"},
+					References: []Reference{
+						{ForeignKey: "OwnerType", ForeignSchema: "Toy", PrimaryValue: "users"},
+						{ForeignKey: "OwnerType", ForeignSchema: "Toy", PrimaryValue: "users"},
+					},
+				},
+			},
+		},
+	})
+}
+
+func TestPolymorphic(t *testing.T) {
+	t.Run("has one", func(t *testing.T) {
+		type Toy struct {
+			ID        int
+			Name      string
+			OwnerID   int
+			OwnerType string
+		}
+
+		type Cat struct {
+			ID   int
+			Name string
+			Toy  Toy `gorm:"polymorphic:Owner;"`
+		}
+
+		s, err := schema.Parse(&Cat{}, &sync.Map{}, schema.NamingStrategy{})
+		if err != nil {
+			t.Fatalf("Failed to parse schema, got error %v", err)
+		}
+
+		checkEmbeddedRelations(t, s.Relationships.EmbeddedRelations, map[string]EmbeddedRelations{
+			"Cat": {
+				Relations: map[string]Relation{
+					"Toy": {
+						Name:        "Toy",
+						Type:        schema.HasOne,
+						Schema:      "User",
+						FieldSchema: "Toy",
+						Polymorphic: Polymorphic{ID: "OwnerID", Type: "OwnerType", Value: "users"},
+						References: []Reference{
+							{ForeignKey: "OwnerType", ForeignSchema: "Toy", PrimaryValue: "users"},
+						},
+					},
+				},
+			},
+		})
+	})
+
+	t.Run("has one with custom polymorphic type and id", func(t *testing.T) {
+		type Toy struct {
+			ID    int
+			Name  string
+			RefId int
+			Type  string
+		}
+
+		type Cat struct {
+			ID   int
+			Name string
+			Toy  Toy `gorm:"polymorphic:Owner;polymorphicType:Type;polymorphicId:RefId"`
+		}
+
+		s, err := schema.Parse(&Cat{}, &sync.Map{}, schema.NamingStrategy{})
+		if err != nil {
+			t.Fatalf("Failed to parse schema, got error %v", err)
+		}
+
+		checkEmbeddedRelations(t, s.Relationships.EmbeddedRelations, map[string]EmbeddedRelations{
+			"Cat": {
+				Relations: map[string]Relation{
+					"Toy": {
+						Name:        "Toy",
+						Type:        schema.HasOne,
+						Schema:      "User",
+						FieldSchema: "Toy",
+						Polymorphic: Polymorphic{ID: "ref_id", Type: "Type", Value: "users"},
+						References: []Reference{
+							{ForeignKey: "Type", ForeignSchema: "Toy", PrimaryValue: "users"},
+						},
+					},
+				},
+			},
+		})
+	})
+
+	t.Run("has one with only polymorphic type", func(t *testing.T) {
+		type Toy struct {
+			ID      int
+			Name    string
+			OwnerID int
+			Type    string
+		}
+
+		type Cat struct {
+			ID   int
+			Name string
+			Toy  Toy `gorm:"polymorphic:Owner;polymorphicType:Type"`
+		}
+
+		s, err := schema.Parse(&Cat{}, &sync.Map{}, schema.NamingStrategy{})
+		if err != nil {
+			t.Fatalf("Failed to parse schema, got error %v", err)
+		}
+
+		checkEmbeddedRelations(t, s.Relationships.EmbeddedRelations, map[string]EmbeddedRelations{
+			"Cat": {
+				Relations: map[string]Relation{
+					"Toy": {
+						Name:        "Toy",
+						Type:        schema.HasOne,
+						Schema:      "User",
+						FieldSchema: "Toy",
+						Polymorphic: Polymorphic{ID: "owner_id", Type: "Type", Value: "users"},
+						References: []Reference{
+							{ForeignKey: "Type", ForeignSchema: "Toy", PrimaryValue: "users"},
+						},
+					},
+				},
+			},
+		})
+	})
+
+	t.Run("has many", func(t *testing.T) {
+		type Toy struct {
+			ID        int
+			Name      string
+			OwnerID   int
+			OwnerType string
+		}
+
+		type Cat struct {
+			ID   int
+			Name string
+			Toys []Toy `gorm:"polymorphic:Owner;"`
+		}
+
+		s, err := schema.Parse(&Cat{}, &sync.Map{}, schema.NamingStrategy{})
+		if err != nil {
+			t.Fatalf("Failed to parse schema, got error %v", err)
+		}
+
+		checkEmbeddedRelations(t, s.Relationships.EmbeddedRelations, map[string]EmbeddedRelations{
+			"Cat": {
+				Relations: map[string]Relation{
+					"Toys": {
+						Name:        "Toys",
+						Type:        schema.HasMany,
+						Schema:      "User",
+						FieldSchema: "Toy",
+						Polymorphic: Polymorphic{ID: "OwnerID", Type: "OwnerType", Value: "users"},
+						References: []Reference{
+							{ForeignKey: "OwnerType", ForeignSchema: "Toy", PrimaryValue: "users"},
+						},
+					},
+				},
+			},
+		})
+	})
+
+	t.Run("has many with custom polymorphic type and id", func(t *testing.T) {
+		type Toy struct {
+			ID    int
+			Name  string
+			RefId int
+			Type  string
+		}
+
+		type Cat struct {
+			ID   int
+			Name string
+			Toys []Toy `gorm:"polymorphicType:Type;polymorphicId:RefId"`
+		}
+
+		s, err := schema.Parse(&Cat{}, &sync.Map{}, schema.NamingStrategy{})
+		if err != nil {
+			t.Fatalf("Failed to parse schema, got error %v", err)
+		}
+
+		checkEmbeddedRelations(t, s.Relationships.EmbeddedRelations, map[string]EmbeddedRelations{
+			"Cat": {
+				Relations: map[string]Relation{
+					"Toys": {
+						Name:        "Toys",
+						Type:        schema.HasMany,
+						Schema:      "User",
+						FieldSchema: "Toy",
+						Polymorphic: Polymorphic{ID: "ref_id", Type: "Type", Value: "users"},
+						References: []Reference{
+							{ForeignKey: "Type", ForeignSchema: "Toy", PrimaryValue: "users"},
+						},
+					},
+				},
+			},
+		})
+	})
+}
+
+func TestEmbeddedBelongsTo(t *testing.T) {
+	type Country struct {
+		ID   int `gorm:"primaryKey"`
+		Name string
+	}
+	type Address struct {
+		CountryID int
+		Country   Country
+	}
+	type NestedAddress struct {
+		Address
+	}
+	type CountryMixin struct {
+		CountryID int
+		Country   Country
+	}
+	type Org struct {
+		ID              int
+		PostalAddress   Address `gorm:"embedded;embeddedPrefix:postal_address_"`
+		VisitingAddress Address `gorm:"embedded;embeddedPrefix:visiting_address_"`
+		AddressID       int
+		Address         struct {
+			ID int
+			Address
+		}
+		NestedAddress *NestedAddress `gorm:"embedded;embeddedPrefix:nested_address_"`
+		CountryMixin
+	}
+
+	s, err := schema.Parse(&Org{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Errorf("Failed to parse schema, got error %v", err)
+	}
+
+	checkEmbeddedRelations(t, s.Relationships.EmbeddedRelations, map[string]EmbeddedRelations{
+		"PostalAddress": {
+			Relations: map[string]Relation{
+				"Country": {
+					Name: "Country", Type: schema.BelongsTo, Schema: "Org", FieldSchema: "Country",
+					References: []Reference{
+						{PrimaryKey: "ID", PrimarySchema: "Country", ForeignKey: "CountryID", ForeignSchema: "Org"},
+					},
+				},
+			},
+		},
+		"VisitingAddress": {
+			Relations: map[string]Relation{
+				"Country": {
+					Name: "Country", Type: schema.BelongsTo, Schema: "Org", FieldSchema: "Country",
+					References: []Reference{
+						{PrimaryKey: "ID", PrimarySchema: "Country", ForeignKey: "CountryID", ForeignSchema: "Org"},
+					},
+				},
+			},
+		},
+		"NestedAddress": {
+			Relations: map[string]Relation{
+				"Country": {
+					Name: "Country", Type: schema.BelongsTo, Schema: "Org", FieldSchema: "Country",
+					References: []Reference{
+						{PrimaryKey: "ID", PrimarySchema: "Country", ForeignKey: "CountryID", ForeignSchema: "Org"},
+					},
+				},
+			},
+		},
+	})
+}
+
+func TestVariableRelation(t *testing.T) {
+	var result struct {
+		User
+	}
+
+	checkStructRelation(t, &result, Relation{
+		Name: "Account", Type: schema.HasOne, Schema: "", FieldSchema: "Account",
+		References: []Reference{
+			{"ID", "", "UserID", "Account", "", true},
+		},
+	})
+
+	checkStructRelation(t, &result, Relation{
+		Name: "Company", Type: schema.BelongsTo, Schema: "", FieldSchema: "Company",
+		References: []Reference{
+			{"ID", "Company", "CompanyID", "", "", false},
+		},
+	})
+}
+
 func TestSameForeignKey(t *testing.T) {
 	type UserAux struct {
 		gorm.Model
@@ -482,3 +898,101 @@ func TestSameForeignKey(t *testing.T) {
 		},
 	)
 }
+
+func TestBelongsToSameForeignKey(t *testing.T) {
+	type User struct {
+		gorm.Model
+		Name string
+		UUID string
+	}
+
+	type UserAux struct {
+		gorm.Model
+		Aux  string
+		UUID string
+		User User `gorm:"ForeignKey:UUID;references:UUID;belongsTo"`
+	}
+
+	checkStructRelation(t, &UserAux{},
+		Relation{
+			Name: "User", Type: schema.BelongsTo, Schema: "UserAux", FieldSchema: "User",
+			References: []Reference{
+				{"UUID", "User", "UUID", "UserAux", "", false},
+			},
+		},
+	)
+}
+
+func TestHasOneWithSameForeignKey(t *testing.T) {
+	type Profile struct {
+		gorm.Model
+		Name         string
+		ProfileRefer int // not used in relationship
+	}
+
+	type User struct {
+		gorm.Model
+		Profile      Profile `gorm:"ForeignKey:ID;references:ProfileRefer"`
+		ProfileRefer int
+	}
+
+	checkStructRelation(t, &User{}, Relation{
+		Name: "Profile", Type: schema.HasOne, Schema: "User", FieldSchema: "Profile",
+		References: []Reference{{"ProfileRefer", "User", "ID", "Profile", "", true}},
+	})
+}
+
+func TestHasManySameForeignKey(t *testing.T) {
+	type Profile struct {
+		gorm.Model
+		Name      string
+		UserRefer uint
+	}
+
+	type User struct {
+		gorm.Model
+		UserRefer uint
+		Profile   []Profile `gorm:"ForeignKey:UserRefer"`
+	}
+
+	checkStructRelation(t, &User{}, Relation{
+		Name: "Profile", Type: schema.HasMany, Schema: "User", FieldSchema: "Profile",
+		References: []Reference{{"ID", "User", "UserRefer", "Profile", "", true}},
+	})
+}
+
+type Author struct {
+	gorm.Model
+}
+
+type Book struct {
+	gorm.Model
+	Author   Author
+	AuthorID uint
+}
+
+func (Book) TableName() string {
+	return "my_schema.a_very_very_very_very_very_very_very_very_long_table_name"
+}
+
+func TestParseConstraintNameWithSchemaQualifiedLongTableName(t *testing.T) {
+	s, err := schema.Parse(
+		&Book{},
+		&sync.Map{},
+		schema.NamingStrategy{IdentifierMaxLength: 64},
+	)
+	if err != nil {
+		t.Fatalf("Failed to parse schema")
+	}
+
+	expectedConstraintName := "fk_my_schema_a_very_very_very_very_very_very_very_very_l4db13eec"
+	constraint := s.Relationships.Relations["Author"].ParseConstraint()
+
+	if constraint.Name != expectedConstraintName {
+		t.Fatalf(
+			"expected constraint name %s, got %s",
+			expectedConstraintName,
+			constraint.Name,
+		)
+	}
+}

schema/schema.go

@@ -5,13 +5,29 @@ import (
 	"errors"
 	"fmt"
 	"go/ast"
+	"path"
 	"reflect"
+	"strings"
 	"sync"
 
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/logger"
 )
 
+type callbackType string
+
+const (
+	callbackTypeBeforeCreate callbackType = "BeforeCreate"
+	callbackTypeBeforeUpdate callbackType = "BeforeUpdate"
+	callbackTypeAfterCreate  callbackType = "AfterCreate"
+	callbackTypeAfterUpdate  callbackType = "AfterUpdate"
+	callbackTypeBeforeSave   callbackType = "BeforeSave"
+	callbackTypeAfterSave    callbackType = "AfterSave"
+	callbackTypeBeforeDelete callbackType = "BeforeDelete"
+	callbackTypeAfterDelete  callbackType = "AfterDelete"
+	callbackTypeAfterFind    callbackType = "AfterFind"
+)
+
 // ErrUnsupportedDataType unsupported data type
 var ErrUnsupportedDataType = errors.New("unsupported data type")
 
@@ -25,6 +41,7 @@ type Schema struct {
 	PrimaryFieldDBNames       []string
 	Fields                    []*Field
 	FieldsByName              map[string]*Field
+	FieldsByBindName          map[string]*Field // embedded fields is 'Embed.Field'
 	FieldsByDBName            map[string]*Field
 	FieldsWithDefaultDBValue  []*Field // fields with default value assigned by database
 	Relationships             Relationships
@@ -45,15 +62,16 @@ type Schema struct {
 
 func (schema Schema) String() string {
 	if schema.ModelType.Name() == "" {
-		return fmt.Sprintf("%v(%v)", schema.Name, schema.Table)
+		return fmt.Sprintf("%s(%s)", schema.Name, schema.Table)
 	}
-	return fmt.Sprintf("%v.%v", schema.ModelType.PkgPath(), schema.ModelType.Name())
+	return fmt.Sprintf("%s.%s", schema.ModelType.PkgPath(), schema.ModelType.Name())
 }
 
 func (schema Schema) MakeSlice() reflect.Value {
-	slice := reflect.MakeSlice(reflect.SliceOf(reflect.PtrTo(schema.ModelType)), 0, 20)
+	slice := reflect.MakeSlice(reflect.SliceOf(reflect.PointerTo(schema.ModelType)), 0, 20)
 	results := reflect.New(slice.Type())
 	results.Elem().Set(slice)
+
 	return results
 }
 
@@ -67,17 +85,56 @@ func (schema Schema) LookUpField(name string) *Field {
 	return nil
 }
 
+// LookUpFieldByBindName looks for the closest field in the embedded struct.
+//
+//	type Struct struct {
+//		Embedded struct {
+//			ID string // is selected by LookUpFieldByBindName([]string{"Embedded", "ID"}, "ID")
+//		}
+//		ID string // is selected by LookUpFieldByBindName([]string{"ID"}, "ID")
+//	}
+func (schema Schema) LookUpFieldByBindName(bindNames []string, name string) *Field {
+	if len(bindNames) == 0 {
+		return nil
+	}
+	for i := len(bindNames) - 1; i >= 0; i-- {
+		find := strings.Join(bindNames[:i], ".") + "." + name
+		if field, ok := schema.FieldsByBindName[find]; ok {
+			return field
+		}
+	}
+	return nil
+}
+
 type Tabler interface {
 	TableName() string
 }
 
-// get data type from dialector
+type TablerWithNamer interface {
+	TableName(Namer) string
+}
+
+// Parse get data type from dialector
 func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error) {
+	return ParseWithSpecialTableName(dest, cacheStore, namer, "")
+}
+
+// ParseWithSpecialTableName get data type from dialector with extra schema table
+func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Namer, specialTableName string) (*Schema, error) {
 	if dest == nil {
 		return nil, fmt.Errorf("%w: %+v", ErrUnsupportedDataType, dest)
 	}
 
-	modelType := reflect.ValueOf(dest).Type()
+	value := reflect.ValueOf(dest)
+	if value.Kind() == reflect.Ptr && value.IsNil() {
+		value = reflect.New(value.Type().Elem())
+	}
+	modelType := reflect.Indirect(value).Type()
+
+	if modelType.Kind() == reflect.Interface {
+		modelType = reflect.Indirect(reflect.ValueOf(dest)).Elem().Type()
+	}
+
 	for modelType.Kind() == reflect.Slice || modelType.Kind() == reflect.Array || modelType.Kind() == reflect.Ptr {
 		modelType = modelType.Elem()
 	}
@@ -86,11 +143,22 @@ func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error)
 		if modelType.PkgPath() == "" {
 			return nil, fmt.Errorf("%w: %+v", ErrUnsupportedDataType, dest)
 		}
-		return nil, fmt.Errorf("%w: %v.%v", ErrUnsupportedDataType, modelType.PkgPath(), modelType.Name())
+		return nil, fmt.Errorf("%w: %s.%s", ErrUnsupportedDataType, modelType.PkgPath(), modelType.Name())
 	}
 
-	if v, ok := cacheStore.Load(modelType); ok {
+	// Cache the Schema for performance,
+	// Use the modelType or modelType + schemaTable (if it present) as cache key.
+	var schemaCacheKey interface{}
+	if specialTableName != "" {
+		schemaCacheKey = fmt.Sprintf("%p-%s", modelType, specialTableName)
+	} else {
+		schemaCacheKey = modelType
+	}
+
+	// Load exist schema cache, return if exists
+	if v, ok := cacheStore.Load(schemaCacheKey); ok {
 		s := v.(*Schema)
+		// Wait for the initialization of other goroutines to complete
 		<-s.initialized
 		return s, s.err
 	}
@@ -100,28 +168,38 @@ func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error)
 	if tabler, ok := modelValue.Interface().(Tabler); ok {
 		tableName = tabler.TableName()
 	}
+	if tabler, ok := modelValue.Interface().(TablerWithNamer); ok {
+		tableName = tabler.TableName(namer)
+	}
 	if en, ok := namer.(embeddedNamer); ok {
 		tableName = en.Table
 	}
-
-	schema := &Schema{
-		Name:           modelType.Name(),
-		ModelType:      modelType,
-		Table:          tableName,
-		FieldsByName:   map[string]*Field{},
-		FieldsByDBName: map[string]*Field{},
-		Relationships:  Relationships{Relations: map[string]*Relationship{}},
-		cacheStore:     cacheStore,
-		namer:          namer,
-		initialized:    make(chan struct{}),
+	if specialTableName != "" && specialTableName != tableName {
+		tableName = specialTableName
 	}
 
-	defer func() {
-		if schema.err != nil {
-			logger.Default.Error(context.Background(), schema.err.Error())
-			cacheStore.Delete(modelType)
-		}
-	}()
+	schema := &Schema{
+		Name:             modelType.Name(),
+		ModelType:        modelType,
+		Table:            tableName,
+		FieldsByName:     map[string]*Field{},
+		FieldsByBindName: map[string]*Field{},
+		FieldsByDBName:   map[string]*Field{},
+		Relationships:    Relationships{Relations: map[string]*Relationship{}},
+		cacheStore:       cacheStore,
+		namer:            namer,
+		initialized:      make(chan struct{}),
+	}
+	// When the schema initialization is completed, the channel will be closed
+	defer close(schema.initialized)
+
+	// Load exist schema cache, return if exists
+	if v, ok := cacheStore.Load(schemaCacheKey); ok {
+		s := v.(*Schema)
+		// Wait for the initialization of other goroutines to complete
+		<-s.initialized
+		return s, s.err
+	}
 
 	for i := 0; i < modelType.NumField(); i++ {
 		if fieldStruct := modelType.Field(i); ast.IsExported(fieldStruct.Name) {
@@ -138,6 +216,7 @@ func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error)
 			field.DBName = namer.ColumnName(schema.Table, field.Name)
 		}
 
+		bindName := field.BindName()
 		if field.DBName != "" {
 			// nonexistence or shortest path or first appear prioritized if has permission
 			if v, ok := schema.FieldsByDBName[field.DBName]; !ok || ((field.Creatable || field.Updatable || field.Readable) && len(field.BindNames) < len(v.BindNames)) {
@@ -146,6 +225,7 @@ func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error)
 				}
 				schema.FieldsByDBName[field.DBName] = field
 				schema.FieldsByName[field.Name] = field
+				schema.FieldsByBindName[bindName] = field
 
 				if v != nil && v.PrimaryKey {
 					for idx, f := range schema.PrimaryFields {
@@ -164,8 +244,11 @@ func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error)
 		if of, ok := schema.FieldsByName[field.Name]; !ok || of.TagSettings["-"] == "-" {
 			schema.FieldsByName[field.Name] = field
 		}
+		if of, ok := schema.FieldsByBindName[bindName]; !ok || of.TagSettings["-"] == "-" {
+			schema.FieldsByBindName[bindName] = field
+		}
 
-		field.setupValuerAndSetter()
+		field.setupValuerAndSetter(modelType)
 	}
 
 	prioritizedPrimaryField := schema.LookUpField("id")
@@ -183,16 +266,26 @@ func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error)
 		}
 	}
 
-	if schema.PrioritizedPrimaryField == nil && len(schema.PrimaryFields) == 1 {
-		schema.PrioritizedPrimaryField = schema.PrimaryFields[0]
+	if schema.PrioritizedPrimaryField == nil {
+		if len(schema.PrimaryFields) == 1 {
+			schema.PrioritizedPrimaryField = schema.PrimaryFields[0]
+		} else if len(schema.PrimaryFields) > 1 {
+			// If there are multiple primary keys, the AUTOINCREMENT field is prioritized
+			for _, field := range schema.PrimaryFields {
+				if field.AutoIncrement {
+					schema.PrioritizedPrimaryField = field
+					break
+				}
+			}
+		}
 	}
 
 	for _, field := range schema.PrimaryFields {
 		schema.PrimaryFieldDBNames = append(schema.PrimaryFieldDBNames, field.DBName)
 	}
 
-	for _, field := range schema.FieldsByDBName {
-		if field.HasDefaultValue && field.DefaultValueInterface == nil {
+	for _, field := range schema.Fields {
+		if field.DataType != "" && field.HasDefaultValue && field.DefaultValueInterface == nil {
 			schema.FieldsWithDefaultDBValue = append(schema.FieldsWithDefaultDBValue, field)
 		}
 	}
@@ -211,49 +304,71 @@ func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error)
 		}
 	}
 
-	callbacks := []string{"BeforeCreate", "AfterCreate", "BeforeUpdate", "AfterUpdate", "BeforeSave", "AfterSave", "BeforeDelete", "AfterDelete", "AfterFind"}
-	for _, name := range callbacks {
-		if methodValue := modelValue.MethodByName(name); methodValue.IsValid() {
+	callbackTypes := []callbackType{
+		callbackTypeBeforeCreate, callbackTypeAfterCreate,
+		callbackTypeBeforeUpdate, callbackTypeAfterUpdate,
+		callbackTypeBeforeSave, callbackTypeAfterSave,
+		callbackTypeBeforeDelete, callbackTypeAfterDelete,
+		callbackTypeAfterFind,
+	}
+	for _, cbName := range callbackTypes {
+		if methodValue := callBackToMethodValue(modelValue, cbName); methodValue.IsValid() {
 			switch methodValue.Type().String() {
-			case "func(*gorm.DB) error": // TODO hack
-				reflect.Indirect(reflect.ValueOf(schema)).FieldByName(name).SetBool(true)
+			case "func(*gorm.DB) error":
+				expectedPkgPath := path.Dir(reflect.TypeOf(schema).Elem().PkgPath())
+				if inVarPkg := methodValue.Type().In(0).Elem().PkgPath(); inVarPkg == expectedPkgPath {
+					reflect.Indirect(reflect.ValueOf(schema)).FieldByName(string(cbName)).SetBool(true)
+				} else {
+					logger.Default.Warn(context.Background(), "In model %v, the hook function `%v(*gorm.DB) error` has an incorrect parameter type. The expected parameter type is `%v`, but the provided type is `%v`.", schema, cbName, expectedPkgPath, inVarPkg)
+					// PASS
+				}
 			default:
-				logger.Default.Warn(context.Background(), "Model %v don't match %vInterface, should be %v(*gorm.DB)", schema, name, name)
+				logger.Default.Warn(context.Background(), "Model %v don't match %vInterface, should be `%v(*gorm.DB) error`. Please see https://gorm.io/docs/hooks.html", schema, cbName, cbName)
 			}
 		}
 	}
 
-	if v, loaded := cacheStore.LoadOrStore(modelType, schema); loaded {
+	// Cache the schema
+	if v, loaded := cacheStore.LoadOrStore(schemaCacheKey, schema); loaded {
 		s := v.(*Schema)
+		// Wait for the initialization of other goroutines to complete
 		<-s.initialized
 		return s, s.err
 	}
 
-	defer close(schema.initialized)
+	defer func() {
+		if schema.err != nil {
+			logger.Default.Error(context.Background(), schema.err.Error())
+			cacheStore.Delete(modelType)
+		}
+	}()
+
 	if _, embedded := schema.cacheStore.Load(embeddedCacheKey); !embedded {
 		for _, field := range schema.Fields {
-			if field.DataType == "" && (field.Creatable || field.Updatable || field.Readable) {
+			if field.DataType == "" && field.GORMDataType == "" && (field.Creatable || field.Updatable || field.Readable) {
 				if schema.parseRelation(field); schema.err != nil {
 					return schema, schema.err
 				} else {
 					schema.FieldsByName[field.Name] = field
+					schema.FieldsByBindName[field.BindName()] = field
 				}
 			}
 
 			fieldValue := reflect.New(field.IndirectFieldType)
-			if fc, ok := fieldValue.Interface().(CreateClausesInterface); ok {
+			fieldInterface := fieldValue.Interface()
+			if fc, ok := fieldInterface.(CreateClausesInterface); ok {
 				field.Schema.CreateClauses = append(field.Schema.CreateClauses, fc.CreateClauses(field)...)
 			}
 
-			if fc, ok := fieldValue.Interface().(QueryClausesInterface); ok {
+			if fc, ok := fieldInterface.(QueryClausesInterface); ok {
 				field.Schema.QueryClauses = append(field.Schema.QueryClauses, fc.QueryClauses(field)...)
 			}
 
-			if fc, ok := fieldValue.Interface().(UpdateClausesInterface); ok {
+			if fc, ok := fieldInterface.(UpdateClausesInterface); ok {
 				field.Schema.UpdateClauses = append(field.Schema.UpdateClauses, fc.UpdateClauses(field)...)
 			}
 
-			if fc, ok := fieldValue.Interface().(DeleteClausesInterface); ok {
+			if fc, ok := fieldInterface.(DeleteClausesInterface); ok {
 				field.Schema.DeleteClauses = append(field.Schema.DeleteClauses, fc.DeleteClauses(field)...)
 			}
 		}
@@ -262,6 +377,39 @@ func Parse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error)
 	return schema, schema.err
 }
 
+// This unrolling is needed to show to the compiler the exact set of methods
+// that can be used on the modelType.
+// Prior to go1.22 any use of MethodByName would cause the linker to
+// abandon dead code elimination for the entire binary.
+// As of go1.22 the compiler supports one special case of a string constant
+// being passed to MethodByName. For enterprise customers or those building
+// large binaries, this gives a significant reduction in binary size.
+// https://github.com/golang/go/issues/62257
+func callBackToMethodValue(modelType reflect.Value, cbType callbackType) reflect.Value {
+	switch cbType {
+	case callbackTypeBeforeCreate:
+		return modelType.MethodByName(string(callbackTypeBeforeCreate))
+	case callbackTypeAfterCreate:
+		return modelType.MethodByName(string(callbackTypeAfterCreate))
+	case callbackTypeBeforeUpdate:
+		return modelType.MethodByName(string(callbackTypeBeforeUpdate))
+	case callbackTypeAfterUpdate:
+		return modelType.MethodByName(string(callbackTypeAfterUpdate))
+	case callbackTypeBeforeSave:
+		return modelType.MethodByName(string(callbackTypeBeforeSave))
+	case callbackTypeAfterSave:
+		return modelType.MethodByName(string(callbackTypeAfterSave))
+	case callbackTypeBeforeDelete:
+		return modelType.MethodByName(string(callbackTypeBeforeDelete))
+	case callbackTypeAfterDelete:
+		return modelType.MethodByName(string(callbackTypeAfterDelete))
+	case callbackTypeAfterFind:
+		return modelType.MethodByName(string(callbackTypeAfterFind))
+	default:
+		return reflect.ValueOf(nil)
+	}
+}
+
 func getOrParse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, error) {
 	modelType := reflect.ValueOf(dest).Type()
 	for modelType.Kind() == reflect.Slice || modelType.Kind() == reflect.Array || modelType.Kind() == reflect.Ptr {
@@ -272,7 +420,7 @@ func getOrParse(dest interface{}, cacheStore *sync.Map, namer Namer) (*Schema, e
 		if modelType.PkgPath() == "" {
 			return nil, fmt.Errorf("%w: %+v", ErrUnsupportedDataType, dest)
 		}
-		return nil, fmt.Errorf("%w: %v.%v", ErrUnsupportedDataType, modelType.PkgPath(), modelType.Name())
+		return nil, fmt.Errorf("%w: %s.%s", ErrUnsupportedDataType, modelType.PkgPath(), modelType.Name())
 	}
 
 	if v, ok := cacheStore.Load(modelType); ok {

schema/schema_helper_test.go

@@ -1,6 +1,7 @@
 package schema_test
 
 import (
+	"context"
 	"fmt"
 	"reflect"
 	"strings"
@@ -29,7 +30,7 @@ func checkSchema(t *testing.T, s *schema.Schema, v schema.Schema, primaryFields
 			}
 
 			if !found {
-				t.Errorf("schema %v failed to found priamry key: %v", s, field)
+				t.Errorf("schema %v failed to found primary key: %v", s, field)
 			}
 		}
 	})
@@ -162,8 +163,8 @@ func checkSchemaRelation(t *testing.T, s *schema.Schema, relation Relation) {
 					t.Errorf("schema %v relation's join table tablename expects %v, but got %v", s, relation.JoinTable.Table, r.JoinTable.Table)
 				}
 
-				for _, f := range relation.JoinTable.Fields {
-					checkSchemaField(t, r.JoinTable, &f, nil)
+				for i := range relation.JoinTable.Fields {
+					checkSchemaField(t, r.JoinTable, &relation.JoinTable.Fields[i], nil)
 				}
 			}
 
@@ -200,10 +201,41 @@ func checkSchemaRelation(t *testing.T, s *schema.Schema, relation Relation) {
 	})
 }
 
+type EmbeddedRelations struct {
+	Relations         map[string]Relation
+	EmbeddedRelations map[string]EmbeddedRelations
+}
+
+func checkEmbeddedRelations(t *testing.T, actual map[string]*schema.Relationships, expected map[string]EmbeddedRelations) {
+	for name, relations := range actual {
+		rs := expected[name]
+		t.Run("CheckEmbeddedRelations/"+name, func(t *testing.T) {
+			if len(relations.Relations) != len(rs.Relations) {
+				t.Errorf("schema relations count don't match, expects %d, got %d", len(rs.Relations), len(relations.Relations))
+			}
+			if len(relations.EmbeddedRelations) != len(rs.EmbeddedRelations) {
+				t.Errorf("schema embedded relations count don't match, expects %d, got %d", len(rs.EmbeddedRelations), len(relations.EmbeddedRelations))
+			}
+			for n, rel := range relations.Relations {
+				if r, ok := rs.Relations[n]; !ok {
+					t.Errorf("failed to find relation by name %s", n)
+				} else {
+					checkSchemaRelation(t, &schema.Schema{
+						Relationships: schema.Relationships{
+							Relations: map[string]*schema.Relationship{n: rel},
+						},
+					}, r)
+				}
+			}
+			checkEmbeddedRelations(t, relations.EmbeddedRelations, rs.EmbeddedRelations)
+		})
+	}
+}
+
 func checkField(t *testing.T, s *schema.Schema, value reflect.Value, values map[string]interface{}) {
 	for k, v := range values {
 		t.Run("CheckField/"+k, func(t *testing.T) {
-			fv, _ := s.FieldsByDBName[k].ValueOf(value)
+			fv, _ := s.FieldsByDBName[k].ValueOf(context.Background(), value)
 			tests.AssertEqual(t, v, fv)
 		})
 	}

schema/schema_test.go

@@ -19,6 +19,22 @@ func TestParseSchema(t *testing.T) {
 	checkUserSchema(t, user)
 }
 
+func TestParseSchemaWithMap(t *testing.T) {
+	type User struct {
+		tests.User
+		Attrs map[string]string `gorm:"type:Map(String,String);"`
+	}
+
+	user, err := schema.Parse(&User{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("failed to parse user with map, got error %v", err)
+	}
+
+	if field := user.FieldsByName["Attrs"]; field.DataType != "Map(String,String)" {
+		t.Errorf("failed to parse user field Attrs")
+	}
+}
+
 func TestParseSchemaWithPointerFields(t *testing.T) {
 	user, err := schema.Parse(&User{}, &sync.Map{}, schema.NamingStrategy{})
 	if err != nil {
@@ -46,8 +62,8 @@ func checkUserSchema(t *testing.T, user *schema.Schema) {
 		{Name: "Active", DBName: "active", BindNames: []string{"Active"}, DataType: schema.Bool},
 	}
 
-	for _, f := range fields {
-		checkSchemaField(t, user, &f, func(f *schema.Field) {
+	for i := range fields {
+		checkSchemaField(t, user, &fields[i], func(f *schema.Field) {
 			f.Creatable = true
 			f.Updatable = true
 			f.Readable = true
@@ -136,8 +152,8 @@ func TestParseSchemaWithAdvancedDataType(t *testing.T) {
 		{Name: "Admin", DBName: "admin", BindNames: []string{"Admin"}, DataType: schema.Bool},
 	}
 
-	for _, f := range fields {
-		checkSchemaField(t, user, &f, func(f *schema.Field) {
+	for i := range fields {
+		checkSchemaField(t, user, &fields[i], func(f *schema.Field) {
 			f.Creatable = true
 			f.Updatable = true
 			f.Readable = true
@@ -145,8 +161,7 @@ func TestParseSchemaWithAdvancedDataType(t *testing.T) {
 	}
 }
 
-type CustomizeTable struct {
-}
+type CustomizeTable struct{}
 
 func (CustomizeTable) TableName() string {
 	return "customize"
@@ -165,7 +180,6 @@ func TestCustomizeTableName(t *testing.T) {
 
 func TestNestedModel(t *testing.T) {
 	versionUser, err := schema.Parse(&VersionUser{}, &sync.Map{}, schema.NamingStrategy{})
-
 	if err != nil {
 		t.Fatalf("failed to parse nested user, got error %v", err)
 	}
@@ -204,7 +218,6 @@ func TestEmbeddedStruct(t *testing.T) {
 	}
 
 	cropSchema, err := schema.Parse(&Corp{}, &sync.Map{}, schema.NamingStrategy{})
-
 	if err != nil {
 		t.Fatalf("failed to parse embedded struct with primary key, got error %v", err)
 	}
@@ -273,7 +286,6 @@ func TestEmbeddedStructForCustomizedNamingStrategy(t *testing.T) {
 	}
 
 	cropSchema, err := schema.Parse(&Corp{}, &sync.Map{}, CustomizedNamingStrategy{schema.NamingStrategy{}})
-
 	if err != nil {
 		t.Fatalf("failed to parse embedded struct with primary key, got error %v", err)
 	}
@@ -297,3 +309,44 @@ func TestEmbeddedStructForCustomizedNamingStrategy(t *testing.T) {
 		})
 	}
 }
+
+func TestCompositePrimaryKeyWithAutoIncrement(t *testing.T) {
+	type Product struct {
+		ProductID    uint `gorm:"primaryKey;autoIncrement"`
+		LanguageCode uint `gorm:"primaryKey"`
+		Code         string
+		Name         string
+	}
+	type ProductNonAutoIncrement struct {
+		ProductID    uint `gorm:"primaryKey;autoIncrement:false"`
+		LanguageCode uint `gorm:"primaryKey"`
+		Code         string
+		Name         string
+	}
+
+	product, err := schema.Parse(&Product{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("failed to parse product struct with composite primary key, got error %v", err)
+	}
+
+	prioritizedPrimaryField := schema.Field{
+		Name: "ProductID", DBName: "product_id", BindNames: []string{"ProductID"}, DataType: schema.Uint, PrimaryKey: true, Size: 64, HasDefaultValue: true, AutoIncrement: true, TagSettings: map[string]string{"PRIMARYKEY": "PRIMARYKEY", "AUTOINCREMENT": "AUTOINCREMENT"},
+	}
+
+	product.Fields = []*schema.Field{product.PrioritizedPrimaryField}
+
+	checkSchemaField(t, product, &prioritizedPrimaryField, func(f *schema.Field) {
+		f.Creatable = true
+		f.Updatable = true
+		f.Readable = true
+	})
+
+	productNonAutoIncrement, err := schema.Parse(&ProductNonAutoIncrement{}, &sync.Map{}, schema.NamingStrategy{})
+	if err != nil {
+		t.Fatalf("failed to parse productNonAutoIncrement struct with composite primary key, got error %v", err)
+	}
+
+	if productNonAutoIncrement.PrioritizedPrimaryField != nil {
+		t.Fatalf("PrioritizedPrimaryField of non autoincrement composite key should be nil")
+	}
+}

schema/serializer.go

@@ -0,0 +1,173 @@
+package schema
+
+import (
+	"bytes"
+	"context"
+	"database/sql"
+	"database/sql/driver"
+	"encoding/gob"
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+	"time"
+)
+
+var serializerMap = sync.Map{}
+
+// RegisterSerializer register serializer
+func RegisterSerializer(name string, serializer SerializerInterface) {
+	serializerMap.Store(strings.ToLower(name), serializer)
+}
+
+// GetSerializer get serializer
+func GetSerializer(name string) (serializer SerializerInterface, ok bool) {
+	v, ok := serializerMap.Load(strings.ToLower(name))
+	if ok {
+		serializer, ok = v.(SerializerInterface)
+	}
+	return serializer, ok
+}
+
+func init() {
+	RegisterSerializer("json", JSONSerializer{})
+	RegisterSerializer("unixtime", UnixSecondSerializer{})
+	RegisterSerializer("gob", GobSerializer{})
+}
+
+// Serializer field value serializer
+type serializer struct {
+	Field           *Field
+	Serializer      SerializerInterface
+	SerializeValuer SerializerValuerInterface
+	Destination     reflect.Value
+	Context         context.Context
+	value           interface{}
+	fieldValue      interface{}
+}
+
+// Scan implements sql.Scanner interface
+func (s *serializer) Scan(value interface{}) error {
+	s.value = value
+	return nil
+}
+
+// Value implements driver.Valuer interface
+func (s serializer) Value() (driver.Value, error) {
+	return s.SerializeValuer.Value(s.Context, s.Field, s.Destination, s.fieldValue)
+}
+
+// SerializerInterface serializer interface
+type SerializerInterface interface {
+	Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) error
+	SerializerValuerInterface
+}
+
+// SerializerValuerInterface serializer valuer interface
+type SerializerValuerInterface interface {
+	Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (interface{}, error)
+}
+
+// JSONSerializer json serializer
+type JSONSerializer struct{}
+
+// Scan implements serializer interface
+func (JSONSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
+	fieldValue := reflect.New(field.FieldType)
+
+	if dbValue != nil {
+		var bytes []byte
+		switch v := dbValue.(type) {
+		case []byte:
+			bytes = v
+		case string:
+			bytes = []byte(v)
+		default:
+			bytes, err = json.Marshal(v)
+			if err != nil {
+				return err
+			}
+		}
+
+		if len(bytes) > 0 {
+			err = json.Unmarshal(bytes, fieldValue.Interface())
+		}
+	}
+
+	field.ReflectValueOf(ctx, dst).Set(fieldValue.Elem())
+	return
+}
+
+// Value implements serializer interface
+func (JSONSerializer) Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (interface{}, error) {
+	result, err := json.Marshal(fieldValue)
+	if string(result) == "null" {
+		if field.TagSettings["NOT NULL"] != "" {
+			return "", nil
+		}
+		return nil, err
+	}
+	return string(result), err
+}
+
+// UnixSecondSerializer json serializer
+type UnixSecondSerializer struct{}
+
+// Scan implements serializer interface
+func (UnixSecondSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
+	t := sql.NullTime{}
+	if err = t.Scan(dbValue); err == nil && t.Valid {
+		err = field.Set(ctx, dst, t.Time.Unix())
+	}
+
+	return
+}
+
+// Value implements serializer interface
+func (UnixSecondSerializer) Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (result interface{}, err error) {
+	rv := reflect.ValueOf(fieldValue)
+	switch v := fieldValue.(type) {
+	case int64, int, uint, uint64, int32, uint32, int16, uint16:
+		result = time.Unix(reflect.Indirect(rv).Int(), 0).UTC()
+	case *int64, *int, *uint, *uint64, *int32, *uint32, *int16, *uint16:
+		if rv.IsZero() {
+			return nil, nil
+		}
+		result = time.Unix(reflect.Indirect(rv).Int(), 0).UTC()
+	default:
+		err = fmt.Errorf("invalid field type %#v for UnixSecondSerializer, only int, uint supported", v)
+	}
+	return
+}
+
+// GobSerializer gob serializer
+type GobSerializer struct{}
+
+// Scan implements serializer interface
+func (GobSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
+	fieldValue := reflect.New(field.FieldType)
+
+	if dbValue != nil {
+		var bytesValue []byte
+		switch v := dbValue.(type) {
+		case []byte:
+			bytesValue = v
+		default:
+			return fmt.Errorf("failed to unmarshal gob value: %#v", dbValue)
+		}
+		if len(bytesValue) > 0 {
+			decoder := gob.NewDecoder(bytes.NewBuffer(bytesValue))
+			err = decoder.Decode(fieldValue.Interface())
+		}
+	}
+	field.ReflectValueOf(ctx, dst).Set(fieldValue.Elem())
+	return
+}
+
+// Value implements serializer interface
+func (GobSerializer) Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (interface{}, error) {
+	buf := new(bytes.Buffer)
+	err := gob.NewEncoder(buf).Encode(fieldValue)
+	return buf.Bytes(), err
+}

schema/utils.go

@@ -1,6 +1,8 @@
 package schema
 
 import (
+	"context"
+	"fmt"
 	"reflect"
 	"regexp"
 	"strings"
@@ -58,23 +60,31 @@ func removeSettingFromTag(tag reflect.StructTag, names ...string) reflect.Struct
 	return tag
 }
 
+func appendSettingFromTag(tag reflect.StructTag, value string) reflect.StructTag {
+	t := tag.Get("gorm")
+	if strings.Contains(t, value) {
+		return tag
+	}
+	return reflect.StructTag(fmt.Sprintf(`gorm:"%s;%s"`, value, t))
+}
+
 // GetRelationsValues get relations's values from a reflect value
-func GetRelationsValues(reflectValue reflect.Value, rels []*Relationship) (reflectResults reflect.Value) {
+func GetRelationsValues(ctx context.Context, reflectValue reflect.Value, rels []*Relationship) (reflectResults reflect.Value) {
 	for _, rel := range rels {
-		reflectResults = reflect.MakeSlice(reflect.SliceOf(reflect.PtrTo(rel.FieldSchema.ModelType)), 0, 1)
+		reflectResults = reflect.MakeSlice(reflect.SliceOf(reflect.PointerTo(rel.FieldSchema.ModelType)), 0, 1)
 
 		appendToResults := func(value reflect.Value) {
-			if _, isZero := rel.Field.ValueOf(value); !isZero {
-				result := reflect.Indirect(rel.Field.ReflectValueOf(value))
+			if _, isZero := rel.Field.ValueOf(ctx, value); !isZero {
+				result := reflect.Indirect(rel.Field.ReflectValueOf(ctx, value))
 				switch result.Kind() {
 				case reflect.Struct:
 					reflectResults = reflect.Append(reflectResults, result.Addr())
 				case reflect.Slice, reflect.Array:
 					for i := 0; i < result.Len(); i++ {
-						if result.Index(i).Kind() == reflect.Ptr {
-							reflectResults = reflect.Append(reflectResults, result.Index(i))
+						if elem := result.Index(i); elem.Kind() == reflect.Ptr {
+							reflectResults = reflect.Append(reflectResults, elem)
 						} else {
-							reflectResults = reflect.Append(reflectResults, result.Index(i).Addr())
+							reflectResults = reflect.Append(reflectResults, elem.Addr())
 						}
 					}
 				}
@@ -97,7 +107,7 @@ func GetRelationsValues(reflectValue reflect.Value, rels []*Relationship) (refle
 }
 
 // GetIdentityFieldValuesMap get identity map from fields
-func GetIdentityFieldValuesMap(reflectValue reflect.Value, fields []*Field) (map[string][]reflect.Value, [][]interface{}) {
+func GetIdentityFieldValuesMap(ctx context.Context, reflectValue reflect.Value, fields []*Field) (map[string][]reflect.Value, [][]interface{}) {
 	var (
 		results       = [][]interface{}{}
 		dataResults   = map[string][]reflect.Value{}
@@ -105,12 +115,17 @@ func GetIdentityFieldValuesMap(reflectValue reflect.Value, fields []*Field) (map
 		notZero, zero bool
 	)
 
+	if reflectValue.Kind() == reflect.Ptr ||
+		reflectValue.Kind() == reflect.Interface {
+		reflectValue = reflectValue.Elem()
+	}
+
 	switch reflectValue.Kind() {
 	case reflect.Struct:
 		results = [][]interface{}{make([]interface{}, len(fields))}
 
 		for idx, field := range fields {
-			results[0][idx], zero = field.ValueOf(reflectValue)
+			results[0][idx], zero = field.ValueOf(ctx, reflectValue)
 			notZero = notZero || !zero
 		}
 
@@ -123,7 +138,7 @@ func GetIdentityFieldValuesMap(reflectValue reflect.Value, fields []*Field) (map
 		for i := 0; i < reflectValue.Len(); i++ {
 			elem := reflectValue.Index(i)
 			elemKey := elem.Interface()
-			if elem.Kind() != reflect.Ptr {
+			if elem.Kind() != reflect.Ptr && elem.CanAddr() {
 				elemKey = elem.Addr().Interface()
 			}
 
@@ -135,7 +150,7 @@ func GetIdentityFieldValuesMap(reflectValue reflect.Value, fields []*Field) (map
 			fieldValues := make([]interface{}, len(fields))
 			notZero = false
 			for idx, field := range fields {
-				fieldValues[idx], zero = field.ValueOf(elem)
+				fieldValues[idx], zero = field.ValueOf(ctx, elem)
 				notZero = notZero || !zero
 			}
 
@@ -155,12 +170,12 @@ func GetIdentityFieldValuesMap(reflectValue reflect.Value, fields []*Field) (map
 }
 
 // GetIdentityFieldValuesMapFromValues get identity map from fields
-func GetIdentityFieldValuesMapFromValues(values []interface{}, fields []*Field) (map[string][]reflect.Value, [][]interface{}) {
+func GetIdentityFieldValuesMapFromValues(ctx context.Context, values []interface{}, fields []*Field) (map[string][]reflect.Value, [][]interface{}) {
 	resultsMap := map[string][]reflect.Value{}
 	results := [][]interface{}{}
 
 	for _, v := range values {
-		rm, rs := GetIdentityFieldValuesMap(reflect.Indirect(reflect.ValueOf(v)), fields)
+		rm, rs := GetIdentityFieldValuesMap(ctx, reflect.Indirect(reflect.ValueOf(v)), fields)
 		for k, v := range rm {
 			resultsMap[k] = append(resultsMap[k], v...)
 		}
@@ -178,17 +193,18 @@ func ToQueryValues(table string, foreignKeys []string, foreignValues [][]interfa
 		}
 
 		return clause.Column{Table: table, Name: foreignKeys[0]}, queryValues
-	} else {
-		columns := make([]clause.Column, len(foreignKeys))
-		for idx, key := range foreignKeys {
-			columns[idx] = clause.Column{Table: table, Name: key}
-		}
-
-		for idx, r := range foreignValues {
-			queryValues[idx] = r
-		}
-		return columns, queryValues
 	}
+
+	columns := make([]clause.Column, len(foreignKeys))
+	for idx, key := range foreignKeys {
+		columns[idx] = clause.Column{Table: table, Name: key}
+	}
+
+	for idx, r := range foreignValues {
+		queryValues[idx] = r
+	}
+
+	return columns, queryValues
 }
 
 type embeddedNamer struct {

soft_delete.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"reflect"
 
+	"github.com/jinzhu/now"
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/schema"
 )
@@ -45,11 +46,21 @@ func (n *DeletedAt) UnmarshalJSON(b []byte) error {
 }
 
 func (DeletedAt) QueryClauses(f *schema.Field) []clause.Interface {
-	return []clause.Interface{SoftDeleteQueryClause{Field: f}}
+	return []clause.Interface{SoftDeleteQueryClause{Field: f, ZeroValue: parseZeroValueTag(f)}}
+}
+
+func parseZeroValueTag(f *schema.Field) sql.NullString {
+	if v, ok := f.TagSettings["ZEROVALUE"]; ok {
+		if _, err := now.Parse(v); err == nil {
+			return sql.NullString{String: v, Valid: true}
+		}
+	}
+	return sql.NullString{Valid: false}
 }
 
 type SoftDeleteQueryClause struct {
-	Field *schema.Field
+	ZeroValue sql.NullString
+	Field     *schema.Field
 }
 
 func (sd SoftDeleteQueryClause) Name() string {
@@ -63,9 +74,9 @@ func (sd SoftDeleteQueryClause) MergeClause(*clause.Clause) {
 }
 
 func (sd SoftDeleteQueryClause) ModifyStatement(stmt *Statement) {
-	if _, ok := stmt.Clauses["soft_delete_enabled"]; !ok {
+	if _, ok := stmt.Clauses["soft_delete_enabled"]; !ok && !stmt.Statement.Unscoped {
 		if c, ok := stmt.Clauses["WHERE"]; ok {
-			if where, ok := c.Expression.(clause.Where); ok && len(where.Exprs) > 1 {
+			if where, ok := c.Expression.(clause.Where); ok && len(where.Exprs) >= 1 {
 				for _, expr := range where.Exprs {
 					if orCond, ok := expr.(clause.OrConditions); ok && len(orCond.Exprs) == 1 {
 						where.Exprs = []clause.Expression{clause.And(where.Exprs...)}
@@ -78,18 +89,44 @@ func (sd SoftDeleteQueryClause) ModifyStatement(stmt *Statement) {
 		}
 
 		stmt.AddClause(clause.Where{Exprs: []clause.Expression{
-			clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: sd.Field.DBName}, Value: nil},
+			clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: sd.Field.DBName}, Value: sd.ZeroValue},
 		}})
 		stmt.Clauses["soft_delete_enabled"] = clause.Clause{}
 	}
 }
 
+func (DeletedAt) UpdateClauses(f *schema.Field) []clause.Interface {
+	return []clause.Interface{SoftDeleteUpdateClause{Field: f, ZeroValue: parseZeroValueTag(f)}}
+}
+
+type SoftDeleteUpdateClause struct {
+	ZeroValue sql.NullString
+	Field     *schema.Field
+}
+
+func (sd SoftDeleteUpdateClause) Name() string {
+	return ""
+}
+
+func (sd SoftDeleteUpdateClause) Build(clause.Builder) {
+}
+
+func (sd SoftDeleteUpdateClause) MergeClause(*clause.Clause) {
+}
+
+func (sd SoftDeleteUpdateClause) ModifyStatement(stmt *Statement) {
+	if stmt.SQL.Len() == 0 && !stmt.Statement.Unscoped {
+		SoftDeleteQueryClause(sd).ModifyStatement(stmt)
+	}
+}
+
 func (DeletedAt) DeleteClauses(f *schema.Field) []clause.Interface {
-	return []clause.Interface{SoftDeleteDeleteClause{Field: f}}
+	return []clause.Interface{SoftDeleteDeleteClause{Field: f, ZeroValue: parseZeroValueTag(f)}}
 }
 
 type SoftDeleteDeleteClause struct {
-	Field *schema.Field
+	ZeroValue sql.NullString
+	Field     *schema.Field
 }
 
 func (sd SoftDeleteDeleteClause) Name() string {
@@ -103,13 +140,13 @@ func (sd SoftDeleteDeleteClause) MergeClause(*clause.Clause) {
 }
 
 func (sd SoftDeleteDeleteClause) ModifyStatement(stmt *Statement) {
-	if stmt.SQL.String() == "" {
+	if stmt.SQL.Len() == 0 && !stmt.Statement.Unscoped {
 		curTime := stmt.DB.NowFunc()
 		stmt.AddClause(clause.Set{{Column: clause.Column{Name: sd.Field.DBName}, Value: curTime}})
 		stmt.SetColumn(sd.Field.DBName, curTime, true)
 
 		if stmt.Schema != nil {
-			_, queryValues := schema.GetIdentityFieldValuesMap(stmt.ReflectValue, stmt.Schema.PrimaryFields)
+			_, queryValues := schema.GetIdentityFieldValuesMap(stmt.Context, stmt.ReflectValue, stmt.Schema.PrimaryFields)
 			column, values := schema.ToQueryValues(stmt.Table, stmt.Schema.PrimaryFieldDBNames, queryValues)
 
 			if len(values) > 0 {
@@ -117,7 +154,7 @@ func (sd SoftDeleteDeleteClause) ModifyStatement(stmt *Statement) {
 			}
 
 			if stmt.ReflectValue.CanAddr() && stmt.Dest != stmt.Model && stmt.Model != nil {
-				_, queryValues = schema.GetIdentityFieldValuesMap(reflect.ValueOf(stmt.Model), stmt.Schema.PrimaryFields)
+				_, queryValues = schema.GetIdentityFieldValuesMap(stmt.Context, reflect.ValueOf(stmt.Model), stmt.Schema.PrimaryFields)
 				column, values = schema.ToQueryValues(stmt.Table, stmt.Schema.PrimaryFieldDBNames, queryValues)
 
 				if len(values) > 0 {
@@ -126,13 +163,8 @@ func (sd SoftDeleteDeleteClause) ModifyStatement(stmt *Statement) {
 			}
 		}
 
-		if _, ok := stmt.Clauses["WHERE"]; !stmt.DB.AllowGlobalUpdate && !ok {
-			stmt.DB.AddError(ErrMissingWhereClause)
-		} else {
-			SoftDeleteQueryClause(sd).ModifyStatement(stmt)
-		}
-
+		SoftDeleteQueryClause(sd).ModifyStatement(stmt)
 		stmt.AddClauseIfNotExists(clause.Update{})
-		stmt.Build("UPDATE", "SET", "WHERE")
+		stmt.Build(stmt.DB.Callback().Update().Clauses...)
 	}
 }

statement.go

@@ -6,6 +6,7 @@ import (
 	"database/sql/driver"
 	"fmt"
 	"reflect"
+	"regexp"
 	"sort"
 	"strconv"
 	"strings"
@@ -27,9 +28,11 @@ type Statement struct {
 	Dest                 interface{}
 	ReflectValue         reflect.Value
 	Clauses              map[string]clause.Clause
+	BuildClauses         []string
 	Distinct             bool
-	Selects              []string // selected columns
-	Omits                []string // omit columns
+	Selects              []string          // selected columns
+	Omits                []string          // omit columns
+	ColumnMapping        map[string]string // map columns
 	Joins                []join
 	Preloads             map[string][]interface{}
 	Settings             sync.Map
@@ -44,11 +47,18 @@ type Statement struct {
 	attrs                []interface{}
 	assigns              []interface{}
 	scopes               []func(*DB) *DB
+	Result               *result
 }
 
 type join struct {
-	Name  string
-	Conds []interface{}
+	Name       string
+	Alias      string
+	Conds      []interface{}
+	On         *clause.Where
+	Selects    []string
+	Omits      []string
+	Expression clause.Expression
+	JoinType   clause.JoinType
 }
 
 // StatementModifier statement modifier interface
@@ -56,12 +66,12 @@ type StatementModifier interface {
 	ModifyStatement(*Statement)
 }
 
-// Write write string
+// WriteString write string
 func (stmt *Statement) WriteString(str string) (int, error) {
 	return stmt.SQL.WriteString(str)
 }
 
-// Write write string
+// WriteByte write byte
 func (stmt *Statement) WriteByte(c byte) error {
 	return stmt.SQL.WriteByte(c)
 }
@@ -73,30 +83,36 @@ func (stmt *Statement) WriteQuoted(value interface{}) {
 
 // QuoteTo write quoted value to writer
 func (stmt *Statement) QuoteTo(writer clause.Writer, field interface{}) {
+	write := func(raw bool, str string) {
+		if raw {
+			writer.WriteString(str)
+		} else {
+			stmt.DB.Dialector.QuoteTo(writer, str)
+		}
+	}
+
 	switch v := field.(type) {
 	case clause.Table:
 		if v.Name == clause.CurrentTable {
 			if stmt.TableExpr != nil {
 				stmt.TableExpr.Build(stmt)
 			} else {
-				stmt.DB.Dialector.QuoteTo(writer, stmt.Table)
+				write(v.Raw, stmt.Table)
 			}
-		} else if v.Raw {
-			writer.WriteString(v.Name)
 		} else {
-			stmt.DB.Dialector.QuoteTo(writer, v.Name)
+			write(v.Raw, v.Name)
 		}
 
 		if v.Alias != "" {
 			writer.WriteByte(' ')
-			stmt.DB.Dialector.QuoteTo(writer, v.Alias)
+			write(v.Raw, v.Alias)
 		}
 	case clause.Column:
 		if v.Table != "" {
 			if v.Table == clause.CurrentTable {
-				stmt.DB.Dialector.QuoteTo(writer, stmt.Table)
+				write(v.Raw, stmt.Table)
 			} else {
-				stmt.DB.Dialector.QuoteTo(writer, v.Table)
+				write(v.Raw, v.Table)
 			}
 			writer.WriteByte('.')
 		}
@@ -105,36 +121,38 @@ func (stmt *Statement) QuoteTo(writer clause.Writer, field interface{}) {
 			if stmt.Schema == nil {
 				stmt.DB.AddError(ErrModelValueRequired)
 			} else if stmt.Schema.PrioritizedPrimaryField != nil {
-				stmt.DB.Dialector.QuoteTo(writer, stmt.Schema.PrioritizedPrimaryField.DBName)
+				write(v.Raw, stmt.Schema.PrioritizedPrimaryField.DBName)
 			} else if len(stmt.Schema.DBNames) > 0 {
-				stmt.DB.Dialector.QuoteTo(writer, stmt.Schema.DBNames[0])
+				write(v.Raw, stmt.Schema.DBNames[0])
+			} else {
+				stmt.DB.AddError(ErrModelAccessibleFieldsRequired) //nolint:typecheck,errcheck
 			}
-		} else if v.Raw {
-			writer.WriteString(v.Name)
 		} else {
-			stmt.DB.Dialector.QuoteTo(writer, v.Name)
+			write(v.Raw, v.Name)
 		}
 
 		if v.Alias != "" {
 			writer.WriteString(" AS ")
-			stmt.DB.Dialector.QuoteTo(writer, v.Alias)
+			write(v.Raw, v.Alias)
 		}
 	case []clause.Column:
 		writer.WriteByte('(')
 		for idx, d := range v {
 			if idx > 0 {
-				writer.WriteString(",")
+				writer.WriteByte(',')
 			}
 			stmt.QuoteTo(writer, d)
 		}
 		writer.WriteByte(')')
+	case clause.Expr:
+		v.Build(stmt)
 	case string:
 		stmt.DB.Dialector.QuoteTo(writer, v)
 	case []string:
 		writer.WriteByte('(')
 		for idx, d := range v {
 			if idx > 0 {
-				writer.WriteString(",")
+				writer.WriteByte(',')
 			}
 			stmt.DB.Dialector.QuoteTo(writer, d)
 		}
@@ -151,7 +169,7 @@ func (stmt *Statement) Quote(field interface{}) string {
 	return builder.String()
 }
 
-// Write write string
+// AddVar add var
 func (stmt *Statement) AddVar(writer clause.Writer, vars ...interface{}) {
 	for idx, v := range vars {
 		if idx > 0 {
@@ -164,10 +182,17 @@ func (stmt *Statement) AddVar(writer clause.Writer, vars ...interface{}) {
 		case clause.Column, clause.Table:
 			stmt.QuoteTo(writer, v)
 		case Valuer:
-			stmt.AddVar(writer, v.GormValue(stmt.Context, stmt.DB))
-		case clause.Expr:
-			v.Build(stmt)
-		case *clause.Expr:
+			reflectValue := reflect.ValueOf(v)
+			if reflectValue.Kind() == reflect.Ptr && reflectValue.IsNil() {
+				stmt.AddVar(writer, nil)
+			} else {
+				stmt.AddVar(writer, v.GormValue(stmt.Context, stmt.DB))
+			}
+		case clause.Interface:
+			c := clause.Clause{Name: v.Name()}
+			v.MergeClause(&c)
+			c.Build(stmt)
+		case clause.Expression:
 			v.Build(stmt)
 		case driver.Valuer:
 			stmt.Vars = append(stmt.Vars, v)
@@ -183,19 +208,21 @@ func (stmt *Statement) AddVar(writer clause.Writer, vars ...interface{}) {
 			} else {
 				writer.WriteString("(NULL)")
 			}
-		case *DB:
-			subdb := v.Session(&Session{Logger: logger.Discard, DryRun: true}).getInstance()
-			if v.Statement.SQL.Len() > 0 {
+		case interface{ getInstance() *DB }:
+			cv := v.getInstance()
+
+			subdb := cv.Session(&Session{Logger: logger.Discard, DryRun: true}).getInstance()
+			if cv.Statement.SQL.Len() > 0 {
 				var (
 					vars = subdb.Statement.Vars
-					sql  = v.Statement.SQL.String()
+					sql  = cv.Statement.SQL.String()
 				)
 
 				subdb.Statement.Vars = make([]interface{}, 0, len(vars))
 				for _, vv := range vars {
 					subdb.Statement.Vars = append(subdb.Statement.Vars, vv)
 					bindvar := strings.Builder{}
-					v.Dialector.BindVarTo(&bindvar, subdb.Statement, vv)
+					cv.BindVarTo(&bindvar, subdb.Statement, vv)
 					sql = strings.Replace(sql, bindvar.String(), "?", 1)
 				}
 
@@ -218,6 +245,9 @@ func (stmt *Statement) AddVar(writer clause.Writer, vars ...interface{}) {
 			case reflect.Slice, reflect.Array:
 				if rv.Len() == 0 {
 					writer.WriteString("(NULL)")
+				} else if rv.Type().Elem() == reflect.TypeOf(uint8(0)) {
+					stmt.Vars = append(stmt.Vars, v)
+					stmt.DB.Dialector.BindVarTo(writer, stmt, v)
 				} else {
 					writer.WriteByte('(')
 					for i := 0; i < rv.Len(); i++ {
@@ -263,13 +293,24 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 		if _, err := strconv.Atoi(s); err != nil {
 			if s == "" && len(args) == 0 {
 				return nil
-			} else if len(args) == 0 || (len(args) > 0 && strings.Contains(s, "?")) {
+			}
+
+			if len(args) == 0 || (len(args) > 0 && strings.Contains(s, "?")) {
 				// looks like a where condition
 				return []clause.Expression{clause.Expr{SQL: s, Vars: args}}
-			} else if len(args) > 0 && strings.Contains(s, "@") {
+			}
+
+			if len(args) > 0 && strings.Contains(s, "@") {
 				// looks like a named query
 				return []clause.Expression{clause.NamedExpr{SQL: s, Vars: args}}
-			} else if len(args) == 1 {
+			}
+
+			if strings.Contains(strings.TrimSpace(s), " ") {
+				// looks like a where condition
+				return []clause.Expression{clause.Expr{SQL: s, Vars: args}}
+			}
+
+			if len(args) == 1 {
 				return []clause.Expression{clause.Eq{Column: s, Value: args[0]}}
 			}
 		}
@@ -278,19 +319,31 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 	conds := make([]clause.Expression, 0, 4)
 	args = append([]interface{}{query}, args...)
 	for idx, arg := range args {
+		if arg == nil {
+			continue
+		}
 		if valuer, ok := arg.(driver.Valuer); ok {
 			arg, _ = valuer.Value()
 		}
 
+		curTable := stmt.Table
+		if curTable == "" {
+			curTable = clause.CurrentTable
+		}
+
 		switch v := arg.(type) {
 		case clause.Expression:
 			conds = append(conds, v)
 		case *DB:
+			v.executeScopes()
+
 			if cs, ok := v.Statement.Clauses["WHERE"]; ok {
 				if where, ok := cs.Expression.(clause.Where); ok {
 					if len(where.Exprs) == 1 {
 						if orConds, ok := where.Exprs[0].(clause.OrConditions); ok {
-							where.Exprs[0] = clause.AndConditions(orConds)
+							if len(orConds.Exprs) == 1 {
+								where.Exprs[0] = clause.AndConditions(orConds)
+							}
 						}
 					}
 					conds = append(conds, clause.And(where.Exprs...))
@@ -303,17 +356,21 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 				conds = append(conds, clause.Eq{Column: i, Value: j})
 			}
 		case map[string]string:
-			var keys = make([]string, 0, len(v))
+			keys := make([]string, 0, len(v))
 			for i := range v {
 				keys = append(keys, i)
 			}
 			sort.Strings(keys)
 
 			for _, key := range keys {
-				conds = append(conds, clause.Eq{Column: key, Value: v[key]})
+				column := clause.Column{Name: key, Table: curTable}
+				if strings.Contains(key, ".") {
+					column = clause.Column{Name: key}
+				}
+				conds = append(conds, clause.Eq{Column: column, Value: v[key]})
 			}
 		case map[string]interface{}:
-			var keys = make([]string, 0, len(v))
+			keys := make([]string, 0, len(v))
 			for i := range v {
 				keys = append(keys, i)
 			}
@@ -321,22 +378,28 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 
 			for _, key := range keys {
 				reflectValue := reflect.Indirect(reflect.ValueOf(v[key]))
+				column := clause.Column{Name: key, Table: curTable}
+				if strings.Contains(key, ".") {
+					column = clause.Column{Name: key}
+				}
 				switch reflectValue.Kind() {
 				case reflect.Slice, reflect.Array:
 					if _, ok := v[key].(driver.Valuer); ok {
-						conds = append(conds, clause.Eq{Column: key, Value: v[key]})
+						conds = append(conds, clause.Eq{Column: column, Value: v[key]})
 					} else if _, ok := v[key].(Valuer); ok {
-						conds = append(conds, clause.Eq{Column: key, Value: v[key]})
+						conds = append(conds, clause.Eq{Column: column, Value: v[key]})
 					} else {
-						values := make([]interface{}, reflectValue.Len())
-						for i := 0; i < reflectValue.Len(); i++ {
+						// optimize reflect value length
+						valueLen := reflectValue.Len()
+						values := make([]interface{}, valueLen)
+						for i := 0; i < valueLen; i++ {
 							values[i] = reflectValue.Index(i).Interface()
 						}
 
-						conds = append(conds, clause.IN{Column: key, Values: values})
+						conds = append(conds, clause.IN{Column: column, Values: values})
 					}
 				default:
-					conds = append(conds, clause.Eq{Column: key, Value: v[key]})
+					conds = append(conds, clause.Eq{Column: column, Value: v[key]})
 				}
 			}
 		default:
@@ -361,11 +424,11 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 					for _, field := range s.Fields {
 						selected := selectedColumns[field.DBName] || selectedColumns[field.Name]
 						if selected || (!restricted && field.Readable) {
-							if v, isZero := field.ValueOf(reflectValue); !isZero || selected {
+							if v, isZero := field.ValueOf(stmt.Context, reflectValue); !isZero || selected {
 								if field.DBName != "" {
-									conds = append(conds, clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: field.DBName}, Value: v})
+									conds = append(conds, clause.Eq{Column: clause.Column{Table: curTable, Name: field.DBName}, Value: v})
 								} else if field.DataType != "" {
-									conds = append(conds, clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: field.Name}, Value: v})
+									conds = append(conds, clause.Eq{Column: clause.Column{Table: curTable, Name: field.Name}, Value: v})
 								}
 							}
 						}
@@ -375,11 +438,11 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 						for _, field := range s.Fields {
 							selected := selectedColumns[field.DBName] || selectedColumns[field.Name]
 							if selected || (!restricted && field.Readable) {
-								if v, isZero := field.ValueOf(reflectValue.Index(i)); !isZero || selected {
+								if v, isZero := field.ValueOf(stmt.Context, reflectValue.Index(i)); !isZero || selected {
 									if field.DBName != "" {
-										conds = append(conds, clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: field.DBName}, Value: v})
+										conds = append(conds, clause.Eq{Column: clause.Column{Table: curTable, Name: field.DBName}, Value: v})
 									} else if field.DataType != "" {
-										conds = append(conds, clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: field.Name}, Value: v})
+										conds = append(conds, clause.Eq{Column: clause.Column{Table: curTable, Name: field.Name}, Value: v})
 									}
 								}
 							}
@@ -396,24 +459,30 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 				if len(args) == 1 {
 					switch reflectValue.Kind() {
 					case reflect.Slice, reflect.Array:
-						values := make([]interface{}, reflectValue.Len())
-						for i := 0; i < reflectValue.Len(); i++ {
+						// optimize reflect value length
+						valueLen := reflectValue.Len()
+						values := make([]interface{}, valueLen)
+						for i := 0; i < valueLen; i++ {
 							values[i] = reflectValue.Index(i).Interface()
 						}
 
 						if len(values) > 0 {
-							conds = append(conds, clause.IN{Column: clause.PrimaryColumn, Values: values})
+							conds = append(conds, clause.IN{Column: clause.Column{Table: curTable, Name: clause.PrimaryKey}, Values: values})
+							return []clause.Expression{clause.And(conds...)}
 						}
-						return conds
+						return nil
 					}
 				}
 
-				conds = append(conds, clause.IN{Column: clause.PrimaryColumn, Values: args})
+				conds = append(conds, clause.IN{Column: clause.Column{Table: curTable, Name: clause.PrimaryKey}, Values: args})
 			}
 		}
 	}
 
-	return conds
+	if len(conds) > 0 {
+		return []clause.Expression{clause.And(conds...)}
+	}
+	return nil
 }
 
 // Build build sql with clauses names
@@ -437,7 +506,11 @@ func (stmt *Statement) Build(clauses ...string) {
 }
 
 func (stmt *Statement) Parse(value interface{}) (err error) {
-	if stmt.Schema, err = schema.Parse(value, stmt.DB.cacheStore, stmt.DB.NamingStrategy); err == nil && stmt.Table == "" {
+	return stmt.ParseWithSpecialTableName(value, "")
+}
+
+func (stmt *Statement) ParseWithSpecialTableName(value interface{}, specialTableName string) (err error) {
+	if stmt.Schema, err = schema.ParseWithSpecialTableName(value, stmt.DB.cacheStore, stmt.DB.NamingStrategy, specialTableName); err == nil && stmt.Table == "" {
 		if tables := strings.Split(stmt.Schema.Table, "."); len(tables) == 2 {
 			stmt.TableExpr = &clause.Expr{SQL: stmt.Quote(stmt.Schema.Table)}
 			stmt.Table = tables[1]
@@ -461,12 +534,14 @@ func (stmt *Statement) clone() *Statement {
 		Distinct:             stmt.Distinct,
 		Selects:              stmt.Selects,
 		Omits:                stmt.Omits,
+		ColumnMapping:        stmt.ColumnMapping,
 		Preloads:             map[string][]interface{}{},
 		ConnPool:             stmt.ConnPool,
 		Schema:               stmt.Schema,
 		Context:              stmt.Context,
 		RaiseErrorOnNotFound: stmt.RaiseErrorOnNotFound,
 		SkipHooks:            stmt.SkipHooks,
+		Result:               stmt.Result,
 	}
 
 	if stmt.SQL.Len() > 0 {
@@ -501,10 +576,10 @@ func (stmt *Statement) clone() *Statement {
 	return newStmt
 }
 
-// Helpers
 // SetColumn set column's value
-//   stmt.SetColumn("Name", "jinzhu") // Hooks Method
-//   stmt.SetColumn("Name", "jinzhu", true) // Callbacks Method
+//
+//	stmt.SetColumn("Name", "jinzhu") // Hooks Method
+//	stmt.SetColumn("Name", "jinzhu", true) // Callbacks Method
 func (stmt *Statement) SetColumn(name string, value interface{}, fromCallbacks ...bool) {
 	if v, ok := stmt.Dest.(map[string]interface{}); ok {
 		v[name] = value
@@ -529,7 +604,7 @@ func (stmt *Statement) SetColumn(name string, value interface{}, fromCallbacks .
 
 				switch destValue.Kind() {
 				case reflect.Struct:
-					field.Set(destValue, value)
+					stmt.AddError(field.Set(stmt.Context, destValue, value))
 				default:
 					stmt.AddError(ErrInvalidData)
 				}
@@ -539,13 +614,18 @@ func (stmt *Statement) SetColumn(name string, value interface{}, fromCallbacks .
 			case reflect.Slice, reflect.Array:
 				if len(fromCallbacks) > 0 {
 					for i := 0; i < stmt.ReflectValue.Len(); i++ {
-						field.Set(stmt.ReflectValue.Index(i), value)
+						stmt.AddError(field.Set(stmt.Context, stmt.ReflectValue.Index(i), value))
 					}
 				} else {
-					field.Set(stmt.ReflectValue.Index(stmt.CurDestIndex), value)
+					stmt.AddError(field.Set(stmt.Context, stmt.ReflectValue.Index(stmt.CurDestIndex), value))
 				}
 			case reflect.Struct:
-				field.Set(stmt.ReflectValue, value)
+				if !stmt.ReflectValue.CanAddr() {
+					stmt.AddError(ErrInvalidValue)
+					return
+				}
+
+				stmt.AddError(field.Set(stmt.Context, stmt.ReflectValue, value))
 			}
 		} else {
 			stmt.AddError(ErrInvalidField)
@@ -565,12 +645,12 @@ func (stmt *Statement) Changed(fields ...string) bool {
 
 	selectColumns, restricted := stmt.SelectAndOmitColumns(false, true)
 	changed := func(field *schema.Field) bool {
-		fieldValue, _ := field.ValueOf(modelValue)
+		fieldValue, _ := field.ValueOf(stmt.Context, modelValue)
 		if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {
-			if v, ok := stmt.Dest.(map[string]interface{}); ok {
-				if fv, ok := v[field.Name]; ok {
+			if mv, mok := stmt.Dest.(map[string]interface{}); mok {
+				if fv, ok := mv[field.Name]; ok {
 					return !utils.AssertEqual(fv, fieldValue)
-				} else if fv, ok := v[field.DBName]; ok {
+				} else if fv, ok := mv[field.DBName]; ok {
 					return !utils.AssertEqual(fv, fieldValue)
 				}
 			} else {
@@ -579,7 +659,10 @@ func (stmt *Statement) Changed(fields ...string) bool {
 					destValue = destValue.Elem()
 				}
 
-				changedValue, zero := field.ValueOf(destValue)
+				changedValue, zero := field.ValueOf(stmt.Context, destValue)
+				if v {
+					return !utils.AssertEqual(changedValue, fieldValue)
+				}
 				return !zero && !utils.AssertEqual(changedValue, fieldValue)
 			}
 		}
@@ -605,44 +688,62 @@ func (stmt *Statement) Changed(fields ...string) bool {
 	return false
 }
 
+var matchName = func() func(tableColumn string) (table, column string) {
+	nameMatcher := regexp.MustCompile(`^(?:\W?(\w+?)\W?\.)?(?:(\*)|\W?(\w+?)\W?)$`)
+	return func(tableColumn string) (table, column string) {
+		if matches := nameMatcher.FindStringSubmatch(tableColumn); len(matches) == 4 {
+			table = matches[1]
+			star := matches[2]
+			columnName := matches[3]
+			if star != "" {
+				return table, star
+			}
+			return table, columnName
+		}
+		return "", ""
+	}
+}()
+
 // SelectAndOmitColumns get select and omit columns, select -> true, omit -> false
 func (stmt *Statement) SelectAndOmitColumns(requireCreate, requireUpdate bool) (map[string]bool, bool) {
 	results := map[string]bool{}
 	notRestricted := false
 
-	// select columns
-	for _, column := range stmt.Selects {
+	processColumn := func(column string, result bool) {
 		if stmt.Schema == nil {
-			results[column] = true
+			results[column] = result
 		} else if column == "*" {
-			notRestricted = true
+			notRestricted = result
 			for _, dbName := range stmt.Schema.DBNames {
-				results[dbName] = true
+				results[dbName] = result
 			}
 		} else if column == clause.Associations {
 			for _, rel := range stmt.Schema.Relationships.Relations {
-				results[rel.Name] = true
+				results[rel.Name] = result
 			}
 		} else if field := stmt.Schema.LookUpField(column); field != nil && field.DBName != "" {
-			results[field.DBName] = true
+			results[field.DBName] = result
+		} else if table, col := matchName(column); col != "" && (table == stmt.Table || table == "") {
+			if col == "*" {
+				for _, dbName := range stmt.Schema.DBNames {
+					results[dbName] = result
+				}
+			} else {
+				results[col] = result
+			}
 		} else {
-			results[column] = true
+			results[column] = result
 		}
 	}
 
+	// select columns
+	for _, column := range stmt.Selects {
+		processColumn(column, true)
+	}
+
 	// omit columns
-	for _, omit := range stmt.Omits {
-		if stmt.Schema == nil {
-			results[omit] = false
-		} else if omit == clause.Associations {
-			for _, rel := range stmt.Schema.Relationships.Relations {
-				results[rel.Name] = false
-			}
-		} else if field := stmt.Schema.LookUpField(omit); field != nil && field.DBName != "" {
-			results[field.DBName] = false
-		} else {
-			results[omit] = false
-		}
+	for _, column := range stmt.Omits {
+		processColumn(column, false)
 	}
 
 	if stmt.Schema != nil {

statement_test.go

@@ -34,3 +34,37 @@ func TestWhereCloneCorruption(t *testing.T) {
 		})
 	}
 }
+
+func TestNilCondition(t *testing.T) {
+	s := new(Statement)
+	if len(s.BuildCondition(nil)) != 0 {
+		t.Errorf("Nil condition should be empty")
+	}
+}
+
+func TestNameMatcher(t *testing.T) {
+	for k, v := range map[string][]string{
+		"table.name":         {"table", "name"},
+		"`table`.`name`":     {"table", "name"},
+		"'table'.'name'":     {"table", "name"},
+		"'table'.name":       {"table", "name"},
+		"table1.name_23":     {"table1", "name_23"},
+		"`table_1`.`name23`": {"table_1", "name23"},
+		"'table23'.'name_1'": {"table23", "name_1"},
+		"'table23'.name1":    {"table23", "name1"},
+		"'name1'":            {"", "name1"},
+		"`name_1`":           {"", "name_1"},
+		"`Name_1`":           {"", "Name_1"},
+		"`Table`.`nAme`":     {"Table", "nAme"},
+		"my_table.*":         {"my_table", "*"},
+		"`my_table`.*":       {"my_table", "*"},
+		"User__Company.*":    {"User__Company", "*"},
+		"`User__Company`.*":  {"User__Company", "*"},
+		`"User__Company".*`:  {"User__Company", "*"},
+		`"table"."*"`:        {"", ""},
+	} {
+		if table, column := matchName(k); table != v[0] || column != v[1] {
+			t.Errorf("failed to match value: %v, got %v, expect: %v", k, []string{table, column}, v)
+		}
+	}
+}

tests/associations_belongs_to_test.go

@@ -3,11 +3,12 @@ package tests_test
 import (
 	"testing"
 
+	"gorm.io/gorm"
 	. "gorm.io/gorm/utils/tests"
 )
 
 func TestBelongsToAssociation(t *testing.T) {
-	var user = *GetUser("belongs-to", Config{Company: true, Manager: true})
+	user := *GetUser("belongs-to", Config{Company: true, Manager: true})
 
 	if err := DB.Create(&user).Error; err != nil {
 		t.Fatalf("errors happened when create: %v", err)
@@ -31,8 +32,8 @@ func TestBelongsToAssociation(t *testing.T) {
 	AssertAssociationCount(t, user, "Manager", 1, "")
 
 	// Append
-	var company = Company{Name: "company-belongs-to-append"}
-	var manager = GetUser("manager-belongs-to-append", Config{})
+	company := Company{Name: "company-belongs-to-append"}
+	manager := GetUser("manager-belongs-to-append", Config{})
 
 	if err := DB.Model(&user2).Association("Company").Append(&company); err != nil {
 		t.Fatalf("Error happened when append Company, got %v", err)
@@ -60,8 +61,8 @@ func TestBelongsToAssociation(t *testing.T) {
 	AssertAssociationCount(t, user2, "Manager", 1, "AfterAppend")
 
 	// Replace
-	var company2 = Company{Name: "company-belongs-to-replace"}
-	var manager2 = GetUser("manager-belongs-to-replace", Config{})
+	company2 := Company{Name: "company-belongs-to-replace"}
+	manager2 := GetUser("manager-belongs-to-replace", Config{})
 
 	if err := DB.Model(&user2).Association("Company").Replace(&company2); err != nil {
 		t.Fatalf("Error happened when replace Company, got %v", err)
@@ -132,10 +133,18 @@ func TestBelongsToAssociation(t *testing.T) {
 
 	AssertAssociationCount(t, user2, "Company", 0, "after clear")
 	AssertAssociationCount(t, user2, "Manager", 0, "after clear")
+
+	// unexist company id
+	unexistCompanyID := company.ID + 9999999
+	user = User{Name: "invalid-user-with-invalid-belongs-to-foreign-key", CompanyID: &unexistCompanyID}
+	if err := DB.Create(&user).Error; err == nil {
+		tidbSkip(t, "not support the foreign key feature")
+		t.Errorf("should have gotten foreign key violation error")
+	}
 }
 
 func TestBelongsToAssociationForSlice(t *testing.T) {
-	var users = []User{
+	users := []User{
 		*GetUser("slice-belongs-to-1", Config{Company: true, Manager: true}),
 		*GetUser("slice-belongs-to-2", Config{Company: true, Manager: false}),
 		*GetUser("slice-belongs-to-3", Config{Company: true, Manager: true}),
@@ -217,3 +226,81 @@ func TestBelongsToAssociationForSlice(t *testing.T) {
 	AssertAssociationCount(t, users[0], "Company", 0, "After Delete")
 	AssertAssociationCount(t, users[1], "Company", 1, "After other user Delete")
 }
+
+func TestBelongsToDefaultValue(t *testing.T) {
+	type Org struct {
+		ID string
+	}
+	type BelongsToUser struct {
+		OrgID string
+		Org   Org `gorm:"default:NULL"`
+	}
+
+	tx := DB.Session(&gorm.Session{})
+	tx.Config.DisableForeignKeyConstraintWhenMigrating = true
+	AssertEqual(t, DB.Config.DisableForeignKeyConstraintWhenMigrating, false)
+
+	tx.Migrator().DropTable(&BelongsToUser{}, &Org{})
+	tx.AutoMigrate(&BelongsToUser{}, &Org{})
+
+	user := &BelongsToUser{
+		Org: Org{
+			ID: "BelongsToUser_Org_1",
+		},
+	}
+	err := DB.Create(&user).Error
+	AssertEqual(t, err, nil)
+}
+
+func TestBelongsToAssociationUnscoped(t *testing.T) {
+	type ItemParent struct {
+		gorm.Model
+		Logo string `gorm:"not null;type:varchar(50)"`
+	}
+	type ItemChild struct {
+		gorm.Model
+		Name         string `gorm:"type:varchar(50)"`
+		ItemParentID uint
+		ItemParent   ItemParent
+	}
+
+	tx := DB.Session(&gorm.Session{})
+	tx.Migrator().DropTable(&ItemParent{}, &ItemChild{})
+	tx.AutoMigrate(&ItemParent{}, &ItemChild{})
+
+	item := ItemChild{
+		Name: "name",
+		ItemParent: ItemParent{
+			Logo: "logo",
+		},
+	}
+	if err := tx.Create(&item).Error; err != nil {
+		t.Fatalf("failed to create items, got error: %v", err)
+	}
+
+	// test replace
+	if err := tx.Model(&item).Association("ItemParent").Unscoped().Replace(&ItemParent{
+		Logo: "updated logo",
+	}); err != nil {
+		t.Errorf("failed to replace item parent, got error: %v", err)
+	}
+
+	var parents []ItemParent
+	if err := tx.Find(&parents).Error; err != nil {
+		t.Errorf("failed to find item parent, got error: %v", err)
+	}
+	if len(parents) != 1 {
+		t.Errorf("expected %d parents, got %d", 1, len(parents))
+	}
+
+	// test delete
+	if err := tx.Model(&item).Association("ItemParent").Unscoped().Delete(&parents); err != nil {
+		t.Errorf("failed to delete item parent, got error: %v", err)
+	}
+	if err := tx.Find(&parents).Error; err != nil {
+		t.Errorf("failed to find item parent, got error: %v", err)
+	}
+	if len(parents) != 0 {
+		t.Errorf("expected %d parents, got %d", 0, len(parents))
+	}
+}