optimize: field.ReflectValueOf (#7530)

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

* fix log

* fix

.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

@@ -3,14 +3,20 @@ 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@v4
+      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 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) ✨"

.github/workflows/labeler.yml

@@ -11,7 +11,7 @@ jobs:
     name: Label issues and pull requests
     steps:
       - name: check out
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: labeler
         uses: jinzhu/super-labeler-action@develop

.github/workflows/missing_playground.yml

@@ -3,14 +3,20 @@ 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@v4
+      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 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) ✨"

.github/workflows/reviewdog.yml

@@ -1,22 +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@v3
-      - name: golangci-lint
-        uses: reviewdog/action-golangci-lint@v2
-
-      - name: Setup reviewdog
-        uses: reviewdog/action-setup@v1
-
-      - name: gofumpt -s with reviewdog
-        env:
-          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          go install mvdan.cc/gofumpt@v0.2.0
-          gofumpt -e -d . | \
-          reviewdog -name="gofumpt" -f=diff -f.diff.strip=0 -reporter=github-pr-review

.github/workflows/stale.yml

@@ -3,14 +3,20 @@ 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@v4
+      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 360 days with no activity. Remove stale label or comment or this will be closed in 180 days"

.github/workflows/tests.yml

@@ -8,26 +8,29 @@ on:
     branches-ignore:
       - 'gh-pages'
 
+permissions:
+  contents: read
+
 jobs:
   # Label of the container job
   sqlite:
     strategy:
       matrix:
-        go: ['1.18', '1.17', '1.16']
+        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@v3
+      uses: actions/checkout@v4
 
     - name: go mod package cache
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
@@ -38,8 +41,8 @@ jobs:
   mysql:
     strategy:
       matrix:
-        dbversion: ['mysql:latest', 'mysql:5.7', 'mariadb:latest']
+        dbversion: ['mysql:9', 'mysql:8', 'mysql:5.7']
-        go: ['1.18', '1.17', '1.16']
+        go: ['1.23', '1.24']
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
 
@@ -62,16 +65,15 @@ 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@v3
+      uses: actions/checkout@v4
-
 
     - name: go mod package cache
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
@@ -79,11 +81,54 @@ jobs:
     - 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
 
+  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:13', 'postgres:12', 'postgres:11', 'postgres:10']
+        dbversion: ['postgres:latest', 'postgres:15', 'postgres:14', 'postgres:13']
-        go: ['1.18', '1.17', '1.16']
+        go: ['1.23', '1.24']
         platform: [ubuntu-latest] # can not run in macOS and Windows
     runs-on: ${{ matrix.platform }}
 
@@ -106,15 +151,15 @@ 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@v3
+      uses: actions/checkout@v4
 
     - name: go mod package cache
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/go/pkg/mod
         key: ${{ runner.os }}-go-${{ matrix.go }}-${{ hashFiles('tests/go.mod') }}
@@ -125,23 +170,21 @@ jobs:
   sqlserver:
     strategy:
       matrix:
-        go: ['1.18', '1.17', '1.16']
+        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_SA_PASSWORD: LoremIpsum86
-          MSSQL_DB: gorm
-          MSSQL_USER: gorm
-          MSSQL_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
@@ -149,18 +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@v3
+      uses: actions/checkout@v4
 
     - name: go mod package cache
-      uses: actions/cache@v3
+      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=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

@@ -3,4 +3,5 @@ documents
 coverage.txt
 _book
 .idea
-vendor
+vendor
+.vscode

.golangci.yml

@@ -1,7 +1,9 @@
+version: "2"
+
 linters:
+  default: standard
   enable:
     - cyclop
-    - exportloopref
     - gocritic
     - gosec
     - ineffassign
@@ -9,3 +11,9 @@ linters:
     - 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)
 
@@ -30,14 +27,18 @@ The fantastic ORM library for Golang, aims to be developer friendly.
 ## Getting Started
 
 * GORM Guides [https://gorm.io](https://gorm.io)
-* GORM Gen    [gorm/gen](https://github.com/go-gorm/gen#gormgen)
+* 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
 }
 
@@ -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 {
@@ -91,6 +117,9 @@ 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
@@ -119,7 +148,11 @@ func (association *Association) Replace(values ...interface{}) error {
 
 			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 (
@@ -184,7 +217,8 @@ 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(association.DB.Statement.Context, reflectValue, rel.Schema.PrimaryFields)
 			if pcolumn, pvalues := schema.ToQueryValues(rel.Schema.Table, rel.Schema.PrimaryFieldDBNames, pvs); len(pvalues) > 0 {
@@ -198,8 +232,21 @@ func (association *Association) Delete(values ...interface{}) error {
 			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(association.DB.Statement.Context, reflectValue, primaryFields)
 			if pcolumn, pvalues := schema.ToQueryValues(rel.FieldSchema.Table, foreignKeys, pvs); len(pvalues) > 0 {
@@ -212,7 +259,11 @@ func (association *Association) Delete(values ...interface{}) error {
 			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
@@ -345,6 +396,10 @@ func (association *Association) saveAssociation(clear bool, values ...interface{
 					}
 				}
 			case reflect.Struct:
+				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 {
@@ -353,9 +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(association.DB.Statement.Context, 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) {
@@ -378,6 +437,10 @@ 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())
 			}
 
@@ -455,6 +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
@@ -476,6 +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 {
@@ -507,7 +576,9 @@ func (association *Association) buildCondition() *DB {
 				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

@@ -75,11 +75,7 @@ func (cs *callbacks) Raw() *processor {
 func (p *processor) Execute(db *DB) *DB {
 	// call scopes
 	for len(db.Statement.scopes) > 0 {
-		scopes := db.Statement.scopes
+		db = db.executeScopes()
-		db.Statement.scopes = nil
-		for _, scope := range scopes {
-			db = scope(db)
-		}
 	}
 
 	var (
@@ -93,6 +89,10 @@ func (p *processor) Execute(db *DB) *DB {
 		resetBuildClauses = true
 	}
 
+	if optimizer, ok := db.Statement.Dest.(StatementModifier); ok {
+		optimizer.ModifyStatement(stmt)
+	}
+
 	// assign model values
 	if stmt.Model == nil {
 		stmt.Model = stmt.Dest
@@ -132,7 +132,11 @@ func (p *processor) Execute(db *DB) *DB {
 
 	if stmt.SQL.Len() > 0 {
 		db.Logger.Trace(stmt.Context, curTime, func() (string, int64) {
-			return db.Dialector.Explain(stmt.SQL.String(), stmt.Vars...), db.RowsAffected
+			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)
 	}
 
@@ -183,10 +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
 
@@ -245,8 +257,14 @@ func sortCallbacks(cs []*callback) (fns []func(*DB), err error) {
 		names, sorted []string
 		sortCallback  func(*callback) error
 	)
-	sort.Slice(cs, func(i, j int) bool {
+	sort.SliceStable(cs, func(i, j int) bool {
-		return cs[j].before == "*" || cs[j].after == "*"
+		if cs[j].before == "*" && cs[i].before != "*" {
+			return true
+		}
+		if cs[j].after == "*" && cs[i].after != "*" {
+			return true
+		}
+		return false
 	})
 
 	for _, c := range cs {
@@ -329,3 +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

@@ -47,29 +47,44 @@ func SaveBeforeAssociations(create bool) func(db *gorm.DB) {
 					)
 
 					if !isPtr {
-						fieldType = reflect.PtrTo(fieldType)
+						fieldType = reflect.PointerTo(fieldType)
 					}
 
 					elems := reflect.MakeSlice(reflect.SliceOf(fieldType), 0, 10)
+					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)
-							if isPtr {
+							elems = reflect.Append(elems, rv)
-								elems = reflect.Append(elems, rv)
+
-							} else {
+							relPrimaryValues := make([]interface{}, 0, len(rel.FieldSchema.PrimaryFields))
-								elems = reflect.Append(elems, rv.Addr())
+							for _, pf := range rel.FieldSchema.PrimaryFields {
+								if pfv, ok := pf.ValueOf(db.Statement.Context, rv); !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, rv)
 							}
 						}
 					}
 
 					if elems.Len() > 0 {
-						if saveAssociations(db, rel, elems, 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))
 							}
@@ -111,7 +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)
@@ -180,7 +195,7 @@ 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{}
@@ -206,9 +221,12 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 								}
 							}
 
-							cacheKey := utils.ToStringKey(relPrimaryValues)
+							cacheKey := utils.ToStringKey(relPrimaryValues...)
 							if len(relPrimaryValues) != len(rel.FieldSchema.PrimaryFields) || !identityMap[cacheKey] {
-								identityMap[cacheKey] = true
+								if cacheKey != "" { // has primary fields
+									identityMap[cacheKey] = true
+								}
+
 								if isPtr {
 									elems = reflect.Append(elems, elem)
 								} else {
@@ -250,10 +268,11 @@ 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) {
@@ -272,19 +291,34 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 					joins = reflect.Append(joins, joinValue)
 				}
 
+				identityMap := map[string]bool{}
 				appendToElems := func(v reflect.Value) {
 					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)
-
+							if !isPtr {
-							objs = append(objs, v)
+								elem = elem.Addr()
-							if isPtr {
-								elems = reflect.Append(elems, elem)
-							} else {
-								elems = reflect.Append(elems, 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)
+							}
+
 						}
 					}
 				}
@@ -304,7 +338,7 @@ func SaveAfterAssociations(create bool) func(db *gorm.DB) {
 				// optimize elems of reflect value length
 				if elemLen := elems.Len(); elemLen > 0 {
 					if v, ok := selectColumns[rel.Name+".*"]; !ok || v {
-						saveAssociations(db, rel, elems, selectColumns, restricted, nil)
+						saveAssociations(db, rel, distinctElems, selectColumns, restricted, nil)
 					}
 
 					for i := 0; i < elemLen; i++ {

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

@@ -3,6 +3,7 @@ package callbacks
 import (
 	"fmt"
 	"reflect"
+	"strings"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
@@ -52,9 +53,13 @@ func Create(config *Config) func(db *gorm.DB) {
 				if _, ok := db.Statement.Clauses["RETURNING"]; !ok {
 					fromColumns := make([]clause.Column, 0, len(db.Statement.Schema.FieldsWithDefaultDBValue))
 					for _, field := range db.Statement.Schema.FieldsWithDefaultDBValue {
-						fromColumns = append(fromColumns, clause.Column{Name: field.DBName})
+						if field.Readable {
+							fromColumns = append(fromColumns, clause.Column{Name: field.DBName})
+						}
+					}
+					if len(fromColumns) > 0 {
+						db.Statement.AddClause(clause.Returning{Columns: fromColumns})
 					}
-					db.Statement.AddClause(clause.Returning{Columns: fromColumns})
 				}
 			}
 		}
@@ -88,6 +93,10 @@ func Create(config *Config) func(db *gorm.DB) {
 					db.AddError(rows.Close())
 				}()
 				gorm.Scan(rows, db, mode)
+
+				if db.Statement.Result != nil {
+					db.Statement.Result.RowsAffected = db.RowsAffected
+				}
 			}
 
 			return
@@ -102,13 +111,70 @@ func Create(config *Config) func(db *gorm.DB) {
 		}
 
 		db.RowsAffected, _ = result.RowsAffected()
-		if db.RowsAffected != 0 && db.Statement.Schema != nil &&
+
-			db.Statement.Schema.PrioritizedPrimaryField != nil &&
+		if db.Statement.Result != nil {
-			db.Statement.Schema.PrioritizedPrimaryField.HasDefaultValue {
+			db.Statement.Result.Result = result
-			insertID, err := result.LastInsertId()
+			db.Statement.Result.RowsAffected = db.RowsAffected
-			insertOk := err == nil && insertID > 0
+		}
-			if !insertOk {
+
+		if db.RowsAffected == 0 {
+			return
+		}
+
+		var (
+			pkField     *schema.Field
+			pkFieldName = "@id"
+		)
+
+		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
+		}
+
+		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
 			}
 
@@ -121,10 +187,10 @@ func Create(config *Config) func(db *gorm.DB) {
 							break
 						}
 
-						_, isZero := db.Statement.Schema.PrioritizedPrimaryField.ValueOf(db.Statement.Context, rv)
+						_, isZero := pkField.ValueOf(db.Statement.Context, rv)
 						if isZero {
-							db.AddError(db.Statement.Schema.PrioritizedPrimaryField.Set(db.Statement.Context, rv, insertID))
+							db.AddError(pkField.Set(db.Statement.Context, rv, insertID))
-							insertID -= db.Statement.Schema.PrioritizedPrimaryField.AutoIncrementIncrement
+							insertID -= pkField.AutoIncrementIncrement
 						}
 					}
 				} else {
@@ -134,16 +200,16 @@ func Create(config *Config) func(db *gorm.DB) {
 							break
 						}
 
-						if _, isZero := db.Statement.Schema.PrioritizedPrimaryField.ValueOf(db.Statement.Context, rv); isZero {
+						if _, isZero := pkField.ValueOf(db.Statement.Context, rv); isZero {
-							db.AddError(db.Statement.Schema.PrioritizedPrimaryField.Set(db.Statement.Context, rv, insertID))
+							db.AddError(pkField.Set(db.Statement.Context, rv, insertID))
-							insertID += db.Statement.Schema.PrioritizedPrimaryField.AutoIncrementIncrement
+							insertID += pkField.AutoIncrementIncrement
 						}
 					}
 				}
 			case reflect.Struct:
-				_, isZero := db.Statement.Schema.PrioritizedPrimaryField.ValueOf(db.Statement.Context, db.Statement.ReflectValue)
+				_, isZero := pkField.ValueOf(db.Statement.Context, db.Statement.ReflectValue)
 				if isZero {
-					db.AddError(db.Statement.Schema.PrioritizedPrimaryField.Set(db.Statement.Context, db.Statement.ReflectValue, insertID))
+					db.AddError(pkField.Set(db.Statement.Context, db.Statement.ReflectValue, insertID))
 				}
 			}
 		}
@@ -252,13 +318,15 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 				}
 			}
 
-			for field, vs := range defaultValueFieldsHavingValue {
+			for _, field := range stmt.Schema.FieldsWithDefaultDBValue {
-				values.Columns = append(values.Columns, clause.Column{Name: field.DBName})
+				if vs, ok := defaultValueFieldsHavingValue[field]; ok {
-				for idx := range values.Values {
+					values.Columns = append(values.Columns, clause.Column{Name: field.DBName})
-					if vs[idx] == nil {
+					for idx := range values.Values {
-						values.Values[idx] = append(values.Values[idx], stmt.Dialector.DefaultValueOf(field))
+						if vs[idx] == nil {
-					} else {
+							values.Values[idx] = append(values.Values[idx], stmt.DefaultValueOf(field))
-						values.Values[idx] = append(values.Values[idx], vs[idx])
+						} else {
+							values.Values[idx] = append(values.Values[idx], vs[idx])
+						}
 					}
 				}
 			}
@@ -281,7 +349,7 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 			}
 
 			for _, field := range stmt.Schema.FieldsWithDefaultDBValue {
-				if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {
+				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], rvOfvalue)
@@ -302,14 +370,15 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 				for _, column := range values.Columns {
 					if field := stmt.Schema.LookUpField(column.Name); field != nil {
 						if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {
-							if !field.PrimaryKey && (!field.HasDefaultValue || field.DefaultValueInterface != nil) && field.AutoCreateTime == 0 {
+							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.UnixNano() / 1e6
+										assignment.Value = curTime.UnixMilli()
 									case schema.UnixSecond:
 										assignment.Value = curTime.Unix()
 									}

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

@@ -157,8 +157,14 @@ func Delete(config *Config) func(db *gorm.DB) {
 			ok, mode := hasReturning(db, supportReturning)
 			if !ok {
 				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
+					}
 				}
 
 				return
@@ -166,6 +172,10 @@ func Delete(config *Config) func(db *gorm.DB) {
 
 			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

@@ -125,7 +125,7 @@ func checkMissingWhereConditions(db *gorm.DB) {
 type visitMap = map[reflect.Value]bool
 
 // Check if circular values, return true if loaded
-func loadOrStoreVisitMap(vistMap *visitMap, v reflect.Value) (loaded bool) {
+func loadOrStoreVisitMap(visitMap *visitMap, v reflect.Value) (loaded bool) {
 	if v.Kind() == reflect.Ptr {
 		v = v.Elem()
 	}
@@ -134,17 +134,17 @@ func loadOrStoreVisitMap(vistMap *visitMap, v reflect.Value) (loaded bool) {
 	case reflect.Slice, reflect.Array:
 		loaded = true
 		for i := 0; i < v.Len(); i++ {
-			if !loadOrStoreVisitMap(vistMap, v.Index(i)) {
+			if !loadOrStoreVisitMap(visitMap, v.Index(i)) {
 				loaded = false
 			}
 		}
 	case reflect.Struct, reflect.Interface:
 		if v.CanAddr() {
 			p := v.Addr()
-			if _, ok := (*vistMap)[p]; ok {
+			if _, ok := (*visitMap)[p]; ok {
 				return true
 			}
-			(*vistMap)[p] = true
+			(*visitMap)[p] = true
 		}
 	}
 

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

@@ -3,6 +3,8 @@ package callbacks
 import (
 	"fmt"
 	"reflect"
+	"sort"
+	"strings"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
@@ -10,6 +12,176 @@ import (
 	"gorm.io/gorm/utils"
 )
 
+// 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     = tx.Statement.ReflectValue
@@ -103,6 +275,8 @@ func preload(tx *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 	column, values := schema.ToQueryValues(clause.CurrentTable, relForeignKeys, foreignValues)
 
 	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)
@@ -111,7 +285,11 @@ func preload(tx *gorm.DB, rel *schema.Relationship, conds []interface{}, preload
 			}
 		}
 
-		if err := tx.Where(clause.IN{Column: column, Values: values}).Find(reflectResults.Addr().Interface(), inlineConds...).Error; err != nil {
+		if len(inlineConds) > 0 {
+			tx = tx.Where(inlineConds[0], inlineConds[1:]...)
+		}
+
+		if err := tx.Find(reflectResults.Addr().Interface()).Error; err != nil {
 			return err
 		}
 	}

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) {
@@ -24,6 +25,10 @@ func Query(db *gorm.DB) {
 				db.AddError(rows.Close())
 			}()
 			gorm.Scan(rows, db, 0)
+
+			if db.Statement.Result != nil {
+				db.Statement.Result.RowsAffected = db.RowsAffected
+			}
 		}
 	}
 }
@@ -109,78 +114,148 @@ func BuildQuerySQL(db *gorm.DB) {
 				}
 			}
 
+			specifiedRelationsName := map[string]string{clause.CurrentTable: clause.CurrentTable}
 			for _, join := range db.Statement.Joins {
-				if db.Statement.Schema == nil {
+				if db.Statement.Schema != nil {
-					fromClause.Joins = append(fromClause.Joins, clause.Join{
+					var isRelations bool // is relations or raw sql
-						Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
+					var relations []*schema.Relationship
-					})
+					relation, ok := db.Statement.Schema.Relationships.Relations[join.Name]
-				} else if relation, ok := db.Statement.Schema.Relationships.Relations[join.Name]; ok {
+					if ok {
-					tableAliasName := relation.Name
+						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
+								}
+							}
 
-					for _, s := range relation.FieldSchema.DBNames {
+							if isNestedJoin {
-						clauseSelect.Columns = append(clauseSelect.Columns, clause.Column{
+								isRelations = true
-							Table: tableAliasName,
+								relations = guessNestedRelations
-							Name:  s,
+							}
-							Alias: tableAliasName + "__" + s,
+						}
+					}
+
+					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},
 						})
 					}
-
-					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},
-							}
-						} 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,
-								}
-							}
-						}
-					}
-
-					{
-						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})
-								}
-							}
-						}
-					}
-
-					fromClause.Joins = append(fromClause.Joins, clause.Join{
-						Type:  clause.LeftJoin,
-						Table: clause.Table{Name: relation.FieldSchema.Table, Alias: tableAliasName},
-						ON:    clause.Where{Exprs: exprs},
-					})
 				} else {
 					fromClause.Joins = append(fromClause.Joins, clause.Join{
 						Expression: clause.NamedExpr{SQL: join.Name, Vars: join.Conds},
@@ -189,7 +264,6 @@ func BuildQuerySQL(db *gorm.DB) {
 			}
 
 			db.Statement.AddClause(fromClause)
-			db.Statement.Joins = nil
 		} else {
 			db.Statement.AddClauseIfNotExists(clause.From{})
 		}
@@ -207,60 +281,27 @@ func Preload(db *gorm.DB) {
 			return
 		}
 
-		preloadMap := map[string]map[string][]interface{}{}
+		joins := make([]string, 0, len(db.Statement.Joins))
-		for name := range db.Statement.Preloads {
+		for _, join := range db.Statement.Joins {
-			preloadFields := strings.Split(name, ".")
+			joins = append(joins, join.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]
-				}
-			}
 		}
 
-		preloadNames := make([]string, 0, len(preloadMap))
+		tx := preloadDB(db, db.Statement.ReflectValue, db.Statement.Dest)
-		for key := range preloadMap {
+		if tx.Error != nil {
-			preloadNames = append(preloadNames, key)
-		}
-		sort.Strings(preloadNames)
-
-		preloadDB := 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 {
-			preloadDB.Statement.Settings.Store(k, v)
-			return true
-		})
-
-		if err := preloadDB.Statement.Parse(db.Statement.Dest); err != nil {
 			return
 		}
-		preloadDB.Statement.ReflectValue = db.Statement.ReflectValue
 
-		for _, name := range preloadNames {
+		db.AddError(preloadEntryPoint(tx, joins, &tx.Statement.Schema.Relationships, db.Statement.Preloads, db.Statement.Preloads[clause.Associations]))
-			if rel := preloadDB.Statement.Schema.Relationships.Relations[name]; rel != nil {
-				db.AddError(preload(preloadDB.Table("").Session(&gorm.Session{}), rel, append(db.Statement.Preloads[name], db.Statement.Preloads[clause.Associations]...), preloadMap[name]))
-			} else {
-				db.AddError(fmt.Errorf("%s: %w for schema %s", name, gorm.ErrUnsupportedRelation, db.Statement.Schema.Name))
-			}
-		}
 	}
 }
 
 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

@@ -13,5 +13,10 @@ func RawExec(db *gorm.DB) {
 		}
 
 		db.RowsAffected, _ = result.RowsAffected()
+
+		if db.Statement.Result != nil {
+			db.Statement.Result.Result = result
+			db.Statement.Result.RowsAffected = db.RowsAffected
+		}
 	}
 }

callbacks/row.go

@@ -7,7 +7,7 @@ import (
 func RowQuery(db *gorm.DB) {
 	if db.Error == nil {
 		BuildQuerySQL(db)
-		if db.DryRun {
+		if db.DryRun || db.Error != nil {
 			return
 		}
 

callbacks/update.go

@@ -70,10 +70,13 @@ func Update(config *Config) func(db *gorm.DB) {
 		if db.Statement.SQL.Len() == 0 {
 			db.Statement.SQL.Grow(180)
 			db.Statement.AddClauseIfNotExists(clause.Update{})
-			if set := ConvertToAssignments(db.Statement); len(set) != 0 {
+			if _, ok := db.Statement.Clauses["SET"]; !ok {
-				db.Statement.AddClause(set)
+				if set := ConvertToAssignments(db.Statement); len(set) != 0 {
-			} else if _, ok := db.Statement.Clauses["SET"]; !ok {
+					defer delete(db.Statement.Clauses, "SET")
-				return
+					db.Statement.AddClause(set)
+				} else {
+					return
+				}
 			}
 
 			db.Statement.Build(db.Statement.BuildClauses...)
@@ -89,6 +92,10 @@ func Update(config *Config) func(db *gorm.DB) {
 					gorm.Scan(rows, db, mode)
 					db.Statement.Dest = dest
 					db.AddError(rows.Close())
+
+					if db.Statement.Result != nil {
+						db.Statement.Result.RowsAffected = db.RowsAffected
+					}
 				}
 			} else {
 				result, err := db.Statement.ConnPool.ExecContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
@@ -96,6 +103,11 @@ func Update(config *Config) func(db *gorm.DB) {
 				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
+				}
 			}
 		}
 	}
@@ -135,7 +147,9 @@ 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.Context, stmt.ReflectValue.Index(i), value)
+				if stmt.ReflectValue.CanAddr() {
+					field.Set(stmt.Context, stmt.ReflectValue.Index(i), value)
+				}
 			}
 		}
 	case reflect.Struct:
@@ -158,21 +172,21 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 		switch stmt.ReflectValue.Kind() {
 		case reflect.Slice, reflect.Array:
 			if size := stmt.ReflectValue.Len(); size > 0 {
-				var primaryKeyExprs []clause.Expression
+				var isZero bool
 				for i := 0; i < size; i++ {
-					exprs := make([]clause.Expression, len(stmt.Schema.PrimaryFields))
+					for _, field := range stmt.Schema.PrimaryFields {
-					var notZero bool
+						_, isZero = field.ValueOf(stmt.Context, stmt.ReflectValue.Index(i))
-					for idx, field := range stmt.Schema.PrimaryFields {
+						if !isZero {
-						value, isZero := field.ValueOf(stmt.Context, stmt.ReflectValue.Index(i))
+							break
-						exprs[idx] = clause.Eq{Column: field.DBName, Value: value}
+						}
-						notZero = notZero || !isZero
-					}
-					if notZero {
-						primaryKeyExprs = append(primaryKeyExprs, clause.And(exprs...))
 					}
 				}
 
-				stmt.AddClause(clause.Where{Exprs: []clause.Expression{clause.Or(primaryKeyExprs...)}})
+				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}}})
+				}
 			}
 		case reflect.Struct:
 			for _, field := range stmt.Schema.PrimaryFields {
@@ -229,7 +243,7 @@ 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})
+							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 {
@@ -241,11 +255,13 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 		}
 	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
 			}
 		}
 
@@ -261,7 +277,7 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 								if field.AutoUpdateTime == schema.UnixNanosecond {
 									value = stmt.DB.NowFunc().UnixNano()
 								} else if field.AutoUpdateTime == schema.UnixMillisecond {
-									value = stmt.DB.NowFunc().UnixNano() / 1e6
+									value = stmt.DB.NowFunc().UnixMilli()
 								} else if field.AutoUpdateTime == schema.UnixSecond {
 									value = stmt.DB.NowFunc().Unix()
 								} else {
@@ -272,7 +288,13 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 
 							if (ok || !isZero) && field.Updatable {
 								set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: value})
-								assignValue(field, value)
+								assignField := field
+								if isDiffSchema {
+									if originField := stmt.Schema.LookUpField(dbName); originField != nil {
+										assignField = originField
+									}
+								}
+								assignValue(assignField, value)
 							}
 						}
 					} else {

callbacks/visit_map_test.go

@@ -1,36 +0,0 @@
-package callbacks
-
-import (
-	"reflect"
-	"testing"
-)
-
-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")
-	}
-}

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")
+//	// update all users's name to `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")
-//    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{}
@@ -41,15 +55,22 @@ 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 {
+		if results := tableRegexp.FindStringSubmatch(name); len(results) == 3 {
-			tx.Statement.Table = results[1]
+			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)}
@@ -65,6 +86,11 @@ func (db *DB) Table(name string, args ...interface{}) (tx *DB) {
 }
 
 // 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
@@ -75,6 +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()
 
@@ -151,7 +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 {
@@ -161,6 +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 {
@@ -170,6 +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 {
@@ -179,26 +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("Account", DB.Select("id").Where("user_id = users.id AND name = ?", "someName").Model(&Account{}))
+//	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()
 
 	if len(args) == 1 {
 		if db, ok := args[0].(*DB); ok {
-			if where, ok := db.Statement.Clauses["WHERE"].Expression.(clause.Where); ok {
+			j := join{
-				tx.Statement.Joins = append(tx.Statement.Joins, join{Name: query, Conds: args, On: &where})
+				Name: query, Conds: args, Selects: db.Statement.Selects,
-				return
+				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})
+	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()
 
@@ -210,6 +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{
@@ -218,13 +302,20 @@ func (db *DB) Having(query interface{}, args ...interface{}) (tx *DB) {
 	return
 }
 
-// Order specify order when retrieve records from database
+// 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("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},
@@ -242,13 +333,27 @@ func (db *DB) Order(value interface{}) (tx *DB) {
 }
 
 // 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})
@@ -256,25 +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 {
+//	func AmountGreaterThan1000(db *gorm.DB) *gorm.DB {
-//         return func (db *gorm.DB) *gorm.DB {
+//	    return db.Where("amount > ?", 1000)
-//             return db.Scopes(AmountGreaterThan1000).Where("status in (?)", status)
+//	}
-//         }
-//     }
 //
-//     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 {
@@ -284,18 +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

@@ -29,6 +29,7 @@ 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{
@@ -43,7 +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

@@ -126,8 +126,8 @@ func (expr NamedExpr) Build(builder Builder) {
 	for _, v := range []byte(expr.SQL) {
 		if v == '@' && !inName {
 			inName = true
-			name = []byte{}
+			name = name[:0]
-		} else if v == ' ' || v == ',' || v == ')' || v == '"' || v == '\'' || v == '`' || v == '\n' || v == ';' {
+		} 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)
@@ -246,15 +246,19 @@ func (eq Eq) Build(builder Builder) {
 
 	switch eq.Value.(type) {
 	case []string, []int, []int32, []int64, []uint, []uint32, []uint64, []interface{}:
-		builder.WriteString(" IN (")
 		rv := reflect.ValueOf(eq.Value)
-		for i := 0; i < rv.Len(); i++ {
+		if rv.Len() == 0 {
-			if i > 0 {
+			builder.WriteString(" IN (NULL)")
-				builder.WriteByte(',')
+		} else {
+			builder.WriteString(" IN (")
+			for i := 0; i < rv.Len(); i++ {
+				if i > 0 {
+					builder.WriteByte(',')
+				}
+				builder.AddVar(builder, rv.Index(i).Interface())
 			}
-			builder.AddVar(builder, rv.Index(i).Interface())
+			builder.WriteByte(')')
 		}
-		builder.WriteByte(')')
 	default:
 		if eqNil(eq.Value) {
 			builder.WriteString(" IS NULL")

clause/expression_test.go

@@ -94,6 +94,16 @@ func TestNamedExpr(t *testing.T) {
 		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"}},
@@ -189,6 +199,11 @@ func TestExpression(t *testing.T) {
 		},
 		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},

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 {
+		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}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Offset: 20}, clause.Limit{Limit: &limit10}},
-			"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: 10, Offset: 20}, clause.Limit{Offset: 30}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit10, Offset: 20}, clause.Limit{Offset: 30}},
-			"SELECT * FROM `users` LIMIT 10 OFFSET 30", nil,
+			"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}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Offset: -10}},
-			"SELECT * FROM `users` LIMIT 10", nil,
+			"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}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Limit: &limitNeg10}},
-			"SELECT * FROM `users` OFFSET 30", nil,
+			"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}},
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Limit{Limit: &limit10, Offset: 20}, clause.Limit{Offset: 30}, clause.Limit{Limit: &limit50}},
-			"SELECT * FROM `users` LIMIT 50 OFFSET 30", nil,
+			"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

@@ -16,27 +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 len(onConflict.TargetWhere.Exprs) > 0 {
-		builder.WriteString(" WHERE ")
-		onConflict.TargetWhere.Build(builder)
-		builder.WriteByte(' ')
-	}
-
 	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 {

clause/returning.go

@@ -26,9 +26,12 @@ func (returning Returning) Build(builder Builder) {
 
 // MergeClause merge order by clauses
 func (returning Returning) MergeClause(clause *Clause) {
-	if v, ok := clause.Expression.(Returning); ok {
+	if v, ok := clause.Expression.(Returning); ok && len(returning.Columns) > 0 {
-		returning.Columns = append(v.Columns, returning.Columns...)
+		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_test.go

@@ -49,16 +49,18 @@ func TestSelect(t *testing.T) {
 					Exprs: []clause.Expression{
 						clause.Expr{
 							SQL: "? as name",
-							Vars: []interface{}{clause.Eq{
+							Vars: []interface{}{
-								Column: clause.Column{Name: "age"},
+								clause.Eq{
-								Value:  18,
+									Column: clause.Column{Name: "age"},
-							},
+									Value:  18,
+								},
 							},
 						},
 					},
 				},
 			}, clause.From{}},
-			"SELECT `age` = ? as name FROM `users`", []interface{}{18},
+			"SELECT `age` = ? as name FROM `users`",
+			[]interface{}{18},
 		},
 	}
 

clause/where.go

@@ -21,6 +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 {
@@ -147,6 +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}
 }
 
@@ -155,19 +166,63 @@ type NotConditions struct {
 }
 
 func (not NotConditions) Build(builder Builder) {
-	if len(not.Exprs) > 1 {
+	anyNegationBuilder := false
-		builder.WriteByte('(')
+	for _, c := range not.Exprs {
+		if _, ok := c.(NegationExpressionBuilder); ok {
+			anyNegationBuilder = true
+			break
+		}
 	}
 
-	for idx, c := range not.Exprs {
+	if anyNegationBuilder {
-		if idx > 0 {
+		if len(not.Exprs) > 1 {
-			builder.WriteString(AndWithSpace)
+			builder.WriteByte('(')
 		}
 
-		if negationBuilder, ok := c.(NegationExpressionBuilder); ok {
+		for idx, c := range not.Exprs {
-			negationBuilder.NegationBuild(builder)
+			if idx > 0 {
-		} else {
+				builder.WriteString(AndWithSpace)
-			builder.WriteString("NOT ")
+			}
+
+			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.ToUpper(e.SQL)
@@ -182,9 +237,9 @@ func (not NotConditions) Build(builder Builder) {
 				builder.WriteByte(')')
 			}
 		}
-	}
 
-	if len(not.Exprs) > 1 {
+		if len(not.Exprs) > 1 {
-		builder.WriteByte(')')
+			builder.WriteByte(')')
+		}
 	}
 }

clause/where_test.go

@@ -63,7 +63,7 @@ func TestWhere(t *testing.T) {
 			[]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` <> ?)",
+			"SELECT * FROM `users` WHERE `age` = ? OR `name` <> ?",
 			[]interface{}{18, "jinzhu"},
 		},
 		{
@@ -94,7 +94,7 @@ func TestWhere(t *testing.T) {
 						clause.And(clause.Expr{SQL: "`score` <= ?", Vars: []interface{}{100}, WithoutParentheses: false})),
 				},
 			}},
-			"SELECT * FROM `users` WHERE (`users`.`id` <> ? AND `score` <= ?)",
+			"SELECT * FROM `users` WHERE `users`.`id` <> ? AND `score` <= ?",
 			[]interface{}{"1", 100},
 		},
 		{
@@ -105,6 +105,30 @@ func TestWhere(t *testing.T) {
 			"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},
+		},
 	}
 
 	for idx, result := range results {

errors.go

@@ -21,6 +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
@@ -41,4 +45,10 @@ var (
 	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)
@@ -24,7 +26,7 @@ func (db *DB) Create(value interface{}) (tx *DB) {
 	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))
 
@@ -33,9 +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 {
@@ -53,7 +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))
@@ -68,12 +71,16 @@ func (db *DB) CreateInBatches(value interface{}, batchSize int) (tx *DB) {
 	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 {
@@ -97,20 +104,19 @@ func (db *DB) Save(value interface{}) (tx *DB) {
 			tx.Statement.Selects = append(tx.Statement.Selects, "*")
 		}
 
-		tx = 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 {
+		if updateTx.Error == nil && updateTx.RowsAffected == 0 && !updateTx.DryRun && !selectedUpdate {
-			result := reflect.New(tx.Statement.Schema.ModelType).Interface()
+			return tx.Session(&Session{SkipHooks: true}).Clauses(clause.OnConflict{UpdateAll: true}).Create(value)
-			if err := tx.Session(&Session{}).Take(result).Error; errors.Is(err, ErrRecordNotFound) {
-				return tx.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},
@@ -125,7 +131,7 @@ func (db *DB) First(dest interface{}, conds ...interface{}) (tx *DB) {
 	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 {
@@ -138,7 +144,7 @@ func (db *DB) Take(dest interface{}, conds ...interface{}) (tx *DB) {
 	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},
@@ -154,7 +160,7 @@ func (db *DB) Last(dest interface{}, conds ...interface{}) (tx *DB) {
 	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 {
@@ -166,7 +172,7 @@ func (db *DB) Find(dest interface{}, conds ...interface{}) (tx *DB) {
 	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{
@@ -177,13 +183,32 @@ 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)
 		}
@@ -192,6 +217,15 @@ func (db *DB) FindInBatches(dest interface{}, batchSize int, fc func(tx *DB, bat
 			break
 		}
 
+		if totalSize > 0 {
+			if totalSize <= int(rowsAffected) {
+				break
+			}
+			if totalSize/batchSize == batch {
+				batchSize = totalSize % batchSize
+			}
+		}
+
 		// Optimize for-break
 		resultsValue := reflect.Indirect(reflect.ValueOf(dest))
 		if result.Statement.Schema.PrioritizedPrimaryField == nil {
@@ -199,7 +233,11 @@ func (db *DB) FindInBatches(dest interface{}, batchSize int, fc func(tx *DB, bat
 			break
 		}
 
-		primaryValue, _ := result.Statement.Schema.PrioritizedPrimaryField.ValueOf(tx.Statement.Context, resultsValue.Index(resultsValue.Len()-1))
+		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})
 	}
 
@@ -256,13 +294,24 @@ func (db *DB) assignInterfacesToValue(values ...interface{}) {
 	}
 }
 
-// FirstOrInit gets the first matched record or initialize a new instance with given conditions (only works with struct or map conditions)
+// 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)
@@ -282,59 +331,82 @@ func (db *DB) FirstOrInit(dest interface{}, conds ...interface{}) (tx *DB) {
 	return
 }
 
-// FirstOrCreate gets the first matched record or create a new one with given conditions (only works with struct, map conditions)
+// 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...); tx.Error == nil {
-		if tx.RowsAffected == 0 {
-			if c, ok := tx.Statement.Clauses["WHERE"]; ok {
-				if where, ok := c.Expression.(clause.Where); ok {
-					tx.assignInterfacesToValue(where.Exprs)
-				}
-			}
 
-			// initialize with attrs, conds
+	result := queryTx.Find(dest, conds...)
-			if len(tx.Statement.attrs) > 0 {
+	if result.Error != nil {
-				tx.assignInterfacesToValue(tx.Statement.attrs...)
+		tx.Error = result.Error
-			}
+		return tx
-
-			// initialize with attrs, conds
-			if len(tx.Statement.assigns) > 0 {
-				tx.assignInterfacesToValue(tx.Statement.assigns...)
-			}
-
-			return tx.Create(dest)
-		} else if len(db.Statement.assigns) > 0 {
-			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 {
-					switch column := eq.Column.(type) {
-					case string:
-						assigns[column] = eq.Value
-					case clause.Column:
-						assigns[column.Name] = eq.Value
-					default:
-					}
-				}
-			}
-
-			return tx.Model(dest).Updates(assigns)
-		}
 	}
+
+	if result.RowsAffected == 0 {
+		if c, ok := result.Statement.Clauses["WHERE"]; ok {
+			if where, ok := c.Expression.(clause.Where); ok {
+				result.assignInterfacesToValue(where.Exprs)
+			}
+		}
+
+		// initialize with attrs, conds
+		if len(db.Statement.attrs) > 0 {
+			result.assignInterfacesToValue(db.Statement.attrs...)
+		}
+
+		// initialize with attrs, conds
+		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(db.Statement.assigns[0], db.Statement.assigns[1:]...)
+		assigns := map[string]interface{}{}
+		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
+				}
+			}
+		}
+
+		return tx.Model(dest).Updates(assigns)
+	}
+
 	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}
 	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
@@ -355,7 +427,9 @@ func (db *DB) UpdateColumns(values interface{}) (tx *DB) {
 	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 {
@@ -449,7 +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()
@@ -463,6 +537,7 @@ func (db *DB) Scan(dest interface{}) (tx *DB) {
 			tx.ScanRows(rows, dest)
 		} else {
 			tx.RowsAffected = 0
+			tx.AddError(rows.Err())
 		}
 		tx.AddError(rows.Close())
 	}
@@ -474,9 +549,10 @@ func (db *DB) Scan(dest interface{}) (tx *DB) {
 	return
 }
 
-// Pluck used to query single column from a model as a map
+// Pluck queries a single column from a model, returning in the slice dest. E.g.:
-//     var ages []int64
+//
-//     db.Model(&users).Pluck("age", &ages)
+//	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 {
@@ -517,7 +593,8 @@ func (db *DB) ScanRows(rows *sql.Rows, dest interface{}) error {
 	return tx.Error
 }
 
-// Connection  use a db conn to execute Multiple commands,this conn will put conn pool after it is executed.
+// 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
@@ -539,27 +616,28 @@ func (db *DB) Connection(fc func(tx *DB) error) (err error) {
 	return fc(tx)
 }
 
-// Transaction start a transaction as a block, return error will rollback, otherwise to commit.
+// 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))
 				}
 			}()
 		}
-
+		err = fc(db.Session(&Session{NewDB: db.clone == 1}))
-		err = fc(db.Session(&Session{}))
 	} else {
 		tx := db.Begin(opts...)
 		if tx.Error != nil {
@@ -583,7 +661,7 @@ 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
@@ -596,11 +674,18 @@ func (db *DB) Begin(opts ...*sql.TxOptions) *DB {
 		opt = opts[0]
 	}
 
+	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(tx.Statement.Context, opt)
+		tx.Statement.ConnPool, err = beginner.BeginTx(ctx, opt)
 	case ConnPoolBeginner:
-		tx.Statement.ConnPool, err = beginner.BeginTx(tx.Statement.Context, opt)
+		tx.Statement.ConnPool, err = beginner.BeginTx(ctx, opt)
 	default:
 		err = ErrInvalidTransaction
 	}
@@ -612,7 +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())
@@ -622,7 +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() {
@@ -636,7 +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)
 	}
@@ -645,14 +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{}

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 v1.1.4
+	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 v1.1.4 h1:tHnRBy1i5F2Dh8BAFxqFzxKqqvezXrL2OW1TnX+Mlas=
+github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=
-github.com/jinzhu/now v1.1.4/go.mod h1:d3SSVoowX0Lcu0IBviAWJpolVfI5UJVZZ7cO71lE/z8=
+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 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"reflect"
 	"sort"
 	"sync"
 	"time"
@@ -20,7 +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
@@ -33,10 +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
@@ -45,6 +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
@@ -105,6 +119,7 @@ type Session struct {
 	DisableNestedTransaction bool
 	AllowGlobalUpdate        bool
 	FullSaveAssociations     bool
+	PropagateUnscoped        bool
 	QueryFields              bool
 	Context                  context.Context
 	Logger                   logger.Interface
@@ -122,12 +137,24 @@ func Open(dialector Dialector, opts ...Option) (db *DB, err error) {
 		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 applyErr := opt.Apply(config); applyErr != nil {
 				return nil, applyErr
 			}
 			defer func(opt Option) {
+				if skipAfterInitialize {
+					return
+				}
 				if errr := opt.AfterInitialize(db); errr != nil {
 					err = errr
 				}
@@ -142,7 +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 {
@@ -175,17 +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{
+			// DB is not initialized, so we skip AfterInitialize
-		ConnPool:    db.ConnPool,
+			skipAfterInitialize = true
-		Stmts:       map[string]Stmt{},
+			return
-		Mux:         &sync.RWMutex{},
+		}
-		PreparedSQL: make([]string, 0, 100),
+
+		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
 	}
 
@@ -236,6 +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
@@ -246,16 +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 {
@@ -300,7 +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),
 	})
 }
@@ -336,10 +391,18 @@ func (db *DB) Callback() *callbacks {
 
 // AddError add error to db
 func (db *DB) AddError(err error) error {
-	if db.Error == nil {
+	if err != nil {
-		db.Error = err
+		if db.Config.TranslateError {
-	} else if err != nil {
+			if errTranslator, ok := db.Dialector.(ErrorTranslator); ok {
-		db.Error = fmt.Errorf("%v; %w", db.Error, err)
+				err = errTranslator.Translate(err)
+			}
+		}
+
+		if db.Error == nil {
+			db.Error = err
+		} else {
+			db.Error = fmt.Errorf("%v; %w", db.Error, err)
+		}
 	}
 	return db.Error
 }
@@ -347,12 +410,20 @@ func (db *DB) AddError(err error) error {
 // DB returns `*sql.DB`
 func (db *DB) DB() (*sql.DB, error) {
 	connPool := db.ConnPool
-
+	if db.Statement != nil && db.Statement.ConnPool != nil {
-	if dbConnector, ok := connPool.(GetDBConnector); ok && dbConnector != nil {
+		connPool = db.Statement.ConnPool
-		return dbConnector.GetDBConn()
+	}
+	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
 	}
 
@@ -366,11 +437,15 @@ func (db *DB) getInstance() *DB {
 		if db.clone == 1 {
 			// clone with new statement
 			tx.Statement = &Statement{
-				DB:       tx,
+				DB:        tx,
-				ConnPool: db.Statement.ConnPool,
+				ConnPool:  db.Statement.ConnPool,
-				Context:  db.Statement.Context,
+				Context:   db.Statement.Context,
-				Clauses:  map[string]clause.Clause{},
+				Clauses:   map[string]clause.Clause{},
-				Vars:     make([]interface{}, 0, 8),
+				Vars:      make([]interface{}, 0, 8),
+				SkipHooks: db.Statement.SkipHooks,
+			}
+			if db.Config.PropagateUnscoped {
+				tx.Statement.Unscoped = db.Statement.Unscoped
 			}
 		} else {
 			// with clone statement
@@ -412,7 +487,7 @@ func (db *DB) SetupJoinTable(model interface{}, field string, joinTable interfac
 	relation, ok := modelSchema.Relationships.Relations[field]
 	isRelation := ok && relation.JoinTable != nil
 	if !isRelation {
-		return fmt.Errorf("failed to found relation: %s", field)
+		return fmt.Errorf("failed to find relation: %s", field)
 	}
 
 	for _, ref := range relation.References {
@@ -455,14 +530,14 @@ func (db *DB) Use(plugin Plugin) error {
 
 // ToSQL for generate SQL string.
 //
-// db.ToSQL(func(tx *gorm.DB) *gorm.DB {
+//	db.ToSQL(func(tx *gorm.DB) *gorm.DB {
-// 		return tx.Model(&User{}).Where(&User{Name: "foo", Age: 20})
+//			return tx.Model(&User{}).Where(&User{Name: "foo", Age: 20})
-// 			.Limit(10).Offset(5)
+//				.Limit(10).Offset(5)
-//			.Order("name ASC")
+//				.Order("name ASC")
-//			.First(&User{})
+//				.First(&User{})
-// })
+//	})
 func (db *DB) ToSQL(queryFn func(tx *DB) *DB) string {
-	tx := queryFn(db.Session(&Session{DryRun: true, SkipDefaultTransaction: true}))
+	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)
@@ -82,3 +86,7 @@ type Rows interface {
 	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

@@ -4,7 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"os"
 	"time"
@@ -55,6 +55,7 @@ type Config struct {
 	SlowThreshold             time.Duration
 	Colorful                  bool
 	IgnoreRecordNotFoundError bool
+	ParameterizedQueries      bool
 	LogLevel                  LogLevel
 }
 
@@ -68,8 +69,8 @@ type Interface interface {
 }
 
 var (
-	// Discard Discard logger will print any log to ioutil.Discard
+	// Discard logger will print any log to io.Discard
-	Discard = New(log.New(ioutil.Discard, "", log.LstdFlags), Config{})
+	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,
@@ -77,8 +78,13 @@ var (
 		IgnoreRecordNotFoundError: false,
 		Colorful:                  true,
 	})
-	// Recorder Recorder logger records running SQL into a recorder instance
+	// 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
@@ -128,28 +134,30 @@ 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) {
+//
+//nolint:cyclop
+func (l *logger) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
 	if l.LogLevel <= Silent {
 		return
 	}
@@ -181,6 +189,14 @@ func (l logger) Trace(ctx context.Context, begin time.Time, fc func() (string, i
 	}
 }
 
+// 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
@@ -189,8 +205,8 @@ type traceRecorder struct {
 	Err          error
 }
 
-// New new trace recorder
+// New trace recorder
-func (l traceRecorder) New() *traceRecorder {
+func (l *traceRecorder) New() *traceRecorder {
 	return &traceRecorder{Interface: l.Interface, BeginAt: time.Now()}
 }
 
@@ -200,3 +216,10 @@ func (l *traceRecorder) Trace(ctx context.Context, begin time.Time, fc func() (s
 	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

@@ -28,8 +28,25 @@ func isPrintable(s string) bool {
 	return true
 }
 
+// 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 (
@@ -75,26 +92,28 @@ func ExplainSQL(sql string, numericPlaceholder *regexp.Regexp, escaper string, a
 			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
+				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
+					vars[idx] = escaper + strings.ReplaceAll(fmt.Sprintf("%v", v), escaper, escaper+escaper) + escaper
 				} else {
 					vars[idx] = nullStr
 				}
 			}
 		case []byte:
 			if s := string(v); isPrintable(s) {
-				vars[idx] = escaper + strings.ReplaceAll(s, escaper, "\\"+escaper) + escaper
+				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:
+		case float32:
-			vars[idx] = fmt.Sprintf("%.6f", v)
+			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.ReplaceAll(v, escaper, "\\"+escaper) + 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() {
@@ -104,6 +123,12 @@ 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 convertibleTypes {
 					if rv.Type().ConvertibleTo(t) {
@@ -111,7 +136,7 @@ func ExplainSQL(sql string, numericPlaceholder *regexp.Regexp, escaper string, a
 						return
 					}
 				}
-				vars[idx] = escaper + strings.ReplaceAll(fmt.Sprint(v), escaper, "\\"+escaper) + escaper
+				vars[idx] = escaper + strings.ReplaceAll(fmt.Sprint(v), escaper, escaper+escaper) + escaper
 			}
 		}
 	}
@@ -138,9 +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.ReplaceAll(string(v), escaper, "\\"+escaper) + 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")
+		tt                 = now.MustParse("2020-02-23 11:10:10")
-		myrole = role("admin")
+		myrole             = role("admin")
-		pwd    = password([]byte("pass"))
+		pwd                = password("pass")
-		jsVal  = []byte(`{"Name":"test","Val":"test"}`)
+		jsVal              = []byte(`{"Name":"test","Val":"test"}`)
-		js     = JSON(jsVal)
+		js                 = JSON(jsVal)
-		esVal  = []byte(`{"Name":"test","Val":"test"}`)
+		esVal              = []byte(`{"Name":"test","Val":"test"}`)
-		es     = ExampleStruct{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

@@ -13,11 +13,7 @@ func (db *DB) Migrator() Migrator {
 
 	// apply scopes to migrator
 	for len(tx.Statement.scopes) > 0 {
-		scopes := tx.Statement.scopes
+		tx = tx.executeScopes()
-		tx.Statement.scopes = nil
-		for _, scope := range scopes {
-			tx = scope(tx)
-		}
 	}
 
 	return tx.Dialector.Migrator(tx.Session(&Session{}))
@@ -30,9 +26,9 @@ func (db *DB) AutoMigrate(dst ...interface{}) error {
 
 // ViewOption view option
 type ViewOption struct {
-	Replace     bool
+	Replace     bool   // If true, exec `CREATE`. If false, exec `CREATE OR REPLACE`
-	CheckOption string
+	CheckOption string // optional. e.g. `WITH [ CASCADED | LOCAL ] CHECK OPTION`
-	Query       *DB
+	Query       *DB    // required subquery.
 }
 
 // ColumnType column type interface
@@ -51,6 +47,23 @@ type ColumnType interface {
 	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
@@ -59,6 +72,7 @@ type Migrator interface {
 	// Database
 	CurrentDatabase() string
 	FullDataTypeOf(*schema.Field) clause.Expr
+	GetTypeAliases(databaseTypeName string) []string
 
 	// Tables
 	CreateTable(dst ...interface{}) error
@@ -66,12 +80,15 @@ type Migrator interface {
 	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)
@@ -90,4 +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/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/migrator.go

@@ -3,20 +3,32 @@ package migrator
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"fmt"
 	"reflect"
 	"regexp"
+	"strconv"
 	"strings"
+	"time"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
+	"gorm.io/gorm/logger"
 	"gorm.io/gorm/schema"
 )
 
-var (
+// This regular expression seeks to find a sequence of digits (\d+) among zero or more non-digit characters (\D*),
-	regRealDataType = regexp.MustCompile(`[^\d](\d+)[^\d]?`)
+// with a possible trailing non-digit character (\D?).
-	regFullDataType = regexp.MustCompile(`[^\d]*(\d+)[^\d]?`)
+
-)
+// For example, values that can pass this regular expression are:
+// - "123"
+// - "abc456"
+// -"%$#@789"
+var regFullDataType = regexp.MustCompile(`\D*(\d+)\D?`)
+
+// TODO:? Create const vars for raw sql queries ?
+
+var _ gorm.Migrator = (*Migrator)(nil)
 
 // Migrator m struct
 type Migrator struct {
@@ -30,6 +42,16 @@ type Config struct {
 	gorm.Dialector
 }
 
+type printSQLLogger struct {
+	logger.Interface
+}
+
+func (l *printSQLLogger) Trace(ctx context.Context, begin time.Time, fc func() (sql string, rowsAffected int64), err error) {
+	sql, _ := fc()
+	fmt.Println(sql + ";")
+	l.Interface.Trace(ctx, begin, fc, err)
+}
+
 // GormDataTypeInterface gorm data type interface
 type GormDataTypeInterface interface {
 	GormDBDataType(*gorm.DB, *schema.Field) string
@@ -72,10 +94,6 @@ func (m Migrator) FullDataTypeOf(field *schema.Field) (expr clause.Expr) {
 		expr.SQL += " NOT NULL"
 	}
 
-	if field.Unique {
-		expr.SQL += " UNIQUE"
-	}
-
 	if field.HasDefaultValue && (field.DefaultValueInterface != nil || field.DefaultValue != "") {
 		if field.DefaultValueInterface != nil {
 			defaultStmt := &gorm.Statement{Vars: []interface{}{field.DefaultValueInterface}}
@@ -89,20 +107,40 @@ func (m Migrator) FullDataTypeOf(field *schema.Field) (expr clause.Expr) {
 	return
 }
 
+func (m Migrator) GetQueryAndExecTx() (queryTx, execTx *gorm.DB) {
+	queryTx = m.DB.Session(&gorm.Session{})
+	execTx = queryTx
+	if m.DB.DryRun {
+		queryTx.DryRun = false
+		execTx = m.DB.Session(&gorm.Session{Logger: &printSQLLogger{Interface: m.DB.Logger}})
+	}
+	return queryTx, execTx
+}
+
 // AutoMigrate auto migrate values
 func (m Migrator) AutoMigrate(values ...interface{}) error {
 	for _, value := range m.ReorderModels(values, true) {
-		tx := m.DB.Session(&gorm.Session{})
+		queryTx, execTx := m.GetQueryAndExecTx()
-		if !tx.Migrator().HasTable(value) {
+		if !queryTx.Migrator().HasTable(value) {
-			if err := tx.Migrator().CreateTable(value); err != nil {
+			if err := execTx.Migrator().CreateTable(value); err != nil {
 				return err
 			}
 		} else {
-			if err := m.RunWithValue(value, func(stmt *gorm.Statement) (errr error) {
+			if err := m.RunWithValue(value, func(stmt *gorm.Statement) error {
-				columnTypes, _ := m.DB.Migrator().ColumnTypes(value)
 
+				if stmt.Schema == nil {
+					return errors.New("failed to get schema")
+				}
+
+				columnTypes, err := queryTx.Migrator().ColumnTypes(value)
+				if err != nil {
+					return err
+				}
+				var (
+					parseIndexes          = stmt.Schema.ParseIndexes()
+					parseCheckConstraints = stmt.Schema.ParseCheckConstraints()
+				)
 				for _, dbName := range stmt.Schema.DBNames {
-					field := stmt.Schema.FieldsByDBName[dbName]
 					var foundColumn gorm.ColumnType
 
 					for _, columnType := range columnTypes {
@@ -114,37 +152,43 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 
 					if foundColumn == nil {
 						// not found, add column
-						if err := tx.Migrator().AddColumn(value, dbName); err != nil {
+						if err = execTx.Migrator().AddColumn(value, dbName); err != nil {
+							return err
+						}
+					} else {
+						// found, smartly migrate
+						field := stmt.Schema.FieldsByDBName[dbName]
+						if err = execTx.Migrator().MigrateColumn(value, field, foundColumn); err != nil {
 							return err
 						}
-					} else if err := m.DB.Migrator().MigrateColumn(value, field, foundColumn); err != nil {
-						// found, smart migrate
-						return err
 					}
 				}
 
-				for _, rel := range stmt.Schema.Relationships.Relations {
+				if !m.DB.DisableForeignKeyConstraintWhenMigrating && !m.DB.IgnoreRelationshipsWhenMigrating {
-					if !m.DB.Config.DisableForeignKeyConstraintWhenMigrating {
+					for _, rel := range stmt.Schema.Relationships.Relations {
+						if rel.Field.IgnoreMigration {
+							continue
+						}
 						if constraint := rel.ParseConstraint(); constraint != nil &&
-							constraint.Schema == stmt.Schema && !tx.Migrator().HasConstraint(value, constraint.Name) {
+							constraint.Schema == stmt.Schema && !queryTx.Migrator().HasConstraint(value, constraint.Name) {
-							if err := tx.Migrator().CreateConstraint(value, constraint.Name); err != nil {
+							if err := execTx.Migrator().CreateConstraint(value, constraint.Name); err != nil {
-								return err
-							}
-						}
-					}
-
-					for _, chk := range stmt.Schema.ParseCheckConstraints() {
-						if !tx.Migrator().HasConstraint(value, chk.Name) {
-							if err := tx.Migrator().CreateConstraint(value, chk.Name); err != nil {
 								return err
 							}
 						}
 					}
 				}
 
-				for _, idx := range stmt.Schema.ParseIndexes() {
+				for _, chk := range parseCheckConstraints {
-					if !tx.Migrator().HasIndex(value, idx.Name) {
+					if !queryTx.Migrator().HasConstraint(value, chk.Name) {
-						if err := tx.Migrator().CreateIndex(value, idx.Name); err != nil {
+						if err := execTx.Migrator().CreateConstraint(value, chk.Name); err != nil {
+							return err
+						}
+					}
+				}
+
+				for _, idx := range parseIndexes {
+					if !queryTx.Migrator().HasIndex(value, idx.Name) {
+						if err := execTx.Migrator().CreateIndex(value, idx.Name); err != nil {
 							return err
 						}
 					}
@@ -171,7 +215,12 @@ func (m Migrator) GetTables() (tableList []string, err error) {
 func (m Migrator) CreateTable(values ...interface{}) error {
 	for _, value := range m.ReorderModels(values, false) {
 		tx := m.DB.Session(&gorm.Session{})
-		if err := m.RunWithValue(value, func(stmt *gorm.Statement) (errr error) {
+		if err := m.RunWithValue(value, func(stmt *gorm.Statement) (err error) {
+
+			if stmt.Schema == nil {
+				return errors.New("failed to get schema")
+			}
+
 			var (
 				createTableSQL          = "CREATE TABLE ? ("
 				values                  = []interface{}{m.CurrentTable(stmt)}
@@ -182,7 +231,7 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 				field := stmt.Schema.FieldsByDBName[dbName]
 				if !field.IgnoreMigration {
 					createTableSQL += "? ?"
-					hasPrimaryKeyInDataType = hasPrimaryKeyInDataType || strings.Contains(strings.ToUpper(string(field.DataType)), "PRIMARY KEY")
+					hasPrimaryKeyInDataType = hasPrimaryKeyInDataType || strings.Contains(strings.ToUpper(m.DataTypeOf(field)), "PRIMARY KEY")
 					values = append(values, clause.Column{Name: dbName}, m.DB.Migrator().FullDataTypeOf(field))
 					createTableSQL += ","
 				}
@@ -190,7 +239,7 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 
 			if !hasPrimaryKeyInDataType && len(stmt.Schema.PrimaryFields) > 0 {
 				createTableSQL += "PRIMARY KEY ?,"
-				primaryKeys := []interface{}{}
+				primaryKeys := make([]interface{}, 0, len(stmt.Schema.PrimaryFields))
 				for _, field := range stmt.Schema.PrimaryFields {
 					primaryKeys = append(primaryKeys, clause.Column{Name: field.DBName})
 				}
@@ -201,8 +250,8 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 			for _, idx := range stmt.Schema.ParseIndexes() {
 				if m.CreateIndexAfterCreateTable {
 					defer func(value interface{}, name string) {
-						if errr == nil {
+						if err == nil {
-							errr = tx.Migrator().CreateIndex(value, name)
+							err = tx.Migrator().CreateIndex(value, name)
 						}
 					}(value, idx.Name)
 				} else {
@@ -220,15 +269,18 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 					}
 
 					createTableSQL += ","
-					values = append(values, clause.Expr{SQL: idx.Name}, tx.Migrator().(BuildIndexOptionsInterface).BuildIndexOptions(idx.Fields, stmt))
+					values = append(values, clause.Column{Name: idx.Name}, tx.Migrator().(BuildIndexOptionsInterface).BuildIndexOptions(idx.Fields, stmt))
 				}
 			}
 
-			for _, rel := range stmt.Schema.Relationships.Relations {
+			if !m.DB.DisableForeignKeyConstraintWhenMigrating && !m.DB.IgnoreRelationshipsWhenMigrating {
-				if !m.DB.DisableForeignKeyConstraintWhenMigrating {
+				for _, rel := range stmt.Schema.Relationships.Relations {
+					if rel.Field.IgnoreMigration {
+						continue
+					}
 					if constraint := rel.ParseConstraint(); constraint != nil {
 						if constraint.Schema == stmt.Schema {
-							sql, vars := buildConstraint(constraint)
+							sql, vars := constraint.Build()
 							createTableSQL += sql + ","
 							values = append(values, vars...)
 						}
@@ -236,6 +288,11 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 				}
 			}
 
+			for _, uni := range stmt.Schema.ParseUniqueConstraints() {
+				createTableSQL += "CONSTRAINT ? UNIQUE (?),"
+				values = append(values, clause.Column{Name: uni.Name}, clause.Expr{SQL: stmt.Quote(uni.Field.DBName)})
+			}
+
 			for _, chk := range stmt.Schema.ParseCheckConstraints() {
 				createTableSQL += "CONSTRAINT ? CHECK (?),"
 				values = append(values, clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint})
@@ -249,8 +306,8 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 				createTableSQL += fmt.Sprint(tableOption)
 			}
 
-			errr = tx.Exec(createTableSQL, values...).Error
+			err = tx.Exec(createTableSQL, values...).Error
-			return errr
+			return err
 		}); err != nil {
 			return err
 		}
@@ -316,6 +373,9 @@ func (m Migrator) RenameTable(oldName, newName interface{}) error {
 func (m Migrator) AddColumn(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		// avoid using the same name field
+		if stmt.Schema == nil {
+			return errors.New("failed to get schema")
+		}
 		f := stmt.Schema.LookUpField(name)
 		if f == nil {
 			return fmt.Errorf("failed to look up field with name: %s", name)
@@ -335,8 +395,10 @@ func (m Migrator) AddColumn(value interface{}, name string) error {
 // DropColumn drop value's `name` column
 func (m Migrator) DropColumn(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		if field := stmt.Schema.LookUpField(name); field != nil {
+		if stmt.Schema != nil {
-			name = field.DBName
+			if field := stmt.Schema.LookUpField(name); field != nil {
+				name = field.DBName
+			}
 		}
 
 		return m.DB.Exec(
@@ -348,13 +410,15 @@ func (m Migrator) DropColumn(value interface{}, name string) error {
 // AlterColumn alter value's `field` column' type based on schema definition
 func (m Migrator) AlterColumn(value interface{}, field string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		if field := stmt.Schema.LookUpField(field); field != nil {
+		if stmt.Schema != nil {
-			fileType := m.FullDataTypeOf(field)
+			if field := stmt.Schema.LookUpField(field); field != nil {
-			return m.DB.Exec(
+				fileType := m.FullDataTypeOf(field)
-				"ALTER TABLE ? ALTER COLUMN ? TYPE ?",
+				return m.DB.Exec(
-				m.CurrentTable(stmt), clause.Column{Name: field.DBName}, fileType,
+					"ALTER TABLE ? ALTER COLUMN ? TYPE ?",
-			).Error
+					m.CurrentTable(stmt), clause.Column{Name: field.DBName}, fileType,
+				).Error
 
+			}
 		}
 		return fmt.Errorf("failed to look up field with name: %s", field)
 	})
@@ -366,8 +430,10 @@ func (m Migrator) HasColumn(value interface{}, field string) bool {
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		currentDatabase := m.DB.Migrator().CurrentDatabase()
 		name := field
-		if field := stmt.Schema.LookUpField(field); field != nil {
+		if stmt.Schema != nil {
-			name = field.DBName
+			if field := stmt.Schema.LookUpField(field); field != nil {
+				name = field.DBName
+			}
 		}
 
 		return m.DB.Raw(
@@ -382,12 +448,14 @@ func (m Migrator) HasColumn(value interface{}, field string) bool {
 // RenameColumn rename value's field name from oldName to newName
 func (m Migrator) RenameColumn(value interface{}, oldName, newName string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		if field := stmt.Schema.LookUpField(oldName); field != nil {
+		if stmt.Schema != nil {
-			oldName = field.DBName
+			if field := stmt.Schema.LookUpField(oldName); field != nil {
-		}
+				oldName = field.DBName
+			}
 
-		if field := stmt.Schema.LookUpField(newName); field != nil {
+			if field := stmt.Schema.LookUpField(newName); field != nil {
-			newName = field.DBName
+				newName = field.DBName
+			}
 		}
 
 		return m.DB.Exec(
@@ -399,56 +467,102 @@ func (m Migrator) RenameColumn(value interface{}, oldName, newName string) error
 
 // MigrateColumn migrate column
 func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnType gorm.ColumnType) error {
+	if field.IgnoreMigration {
+		return nil
+	}
+
 	// found, smart migrate
-	fullDataType := strings.ToLower(m.DB.Migrator().FullDataTypeOf(field).SQL)
+	fullDataType := strings.TrimSpace(strings.ToLower(m.DB.Migrator().FullDataTypeOf(field).SQL))
 	realDataType := strings.ToLower(columnType.DatabaseTypeName())
+	var (
+		alterColumn bool
+		isSameType  = fullDataType == realDataType
+	)
 
-	alterColumn := false
+	if !field.PrimaryKey {
+		// check type
+		if !strings.HasPrefix(fullDataType, realDataType) {
+			// check type aliases
+			aliases := m.DB.Migrator().GetTypeAliases(realDataType)
+			for _, alias := range aliases {
+				if strings.HasPrefix(fullDataType, alias) {
+					isSameType = true
+					break
+				}
+			}
 
-	// check size
+			if !isSameType {
-	if length, ok := columnType.Length(); length != int64(field.Size) {
-		if length > 0 && field.Size > 0 {
-			alterColumn = true
-		} else {
-			// has size in data type and not equal
-			// Since the following code is frequently called in the for loop, reg optimization is needed here
-			matches := regRealDataType.FindAllStringSubmatch(realDataType, -1)
-			matches2 := regFullDataType.FindAllStringSubmatch(fullDataType, -1)
-			if (len(matches) == 1 && matches[0][1] != fmt.Sprint(field.Size) || !field.PrimaryKey) &&
-				(len(matches2) == 1 && matches2[0][1] != fmt.Sprint(length) && ok) {
 				alterColumn = true
 			}
 		}
 	}
 
+	if !isSameType {
+		// check size
+		if length, ok := columnType.Length(); length != int64(field.Size) {
+			if length > 0 && field.Size > 0 {
+				alterColumn = true
+			} else {
+				// has size in data type and not equal
+				// Since the following code is frequently called in the for loop, reg optimization is needed here
+				matches2 := regFullDataType.FindAllStringSubmatch(fullDataType, -1)
+				if !field.PrimaryKey &&
+					(len(matches2) == 1 && matches2[0][1] != fmt.Sprint(length) && ok) {
+					alterColumn = true
+				}
+			}
+		}
+	}
+
 	// check precision
-	if precision, _, ok := columnType.DecimalSize(); ok && int64(field.Precision) != precision {
+	if realDataType == "decimal" || realDataType == "numeric" &&
-		if regexp.MustCompile(fmt.Sprintf("[^0-9]%d[^0-9]", field.Precision)).MatchString(m.DataTypeOf(field)) {
+		regexp.MustCompile(realDataType+`\(.*\)`).FindString(fullDataType) != "" { // if realDataType has no precision,ignore
-			alterColumn = true
+		precision, scale, ok := columnType.DecimalSize()
+		if ok {
+			if !strings.HasPrefix(fullDataType, fmt.Sprintf("%s(%d,%d)", realDataType, precision, scale)) &&
+				!strings.HasPrefix(fullDataType, fmt.Sprintf("%s(%d)", realDataType, precision)) {
+				alterColumn = true
+			}
+		}
+	} else {
+		if precision, _, ok := columnType.DecimalSize(); ok && int64(field.Precision) != precision {
+			if regexp.MustCompile(fmt.Sprintf("[^0-9]%d[^0-9]", field.Precision)).MatchString(m.DataTypeOf(field)) {
+				alterColumn = true
+			}
 		}
 	}
 
 	// check nullable
 	if nullable, ok := columnType.Nullable(); ok && nullable == field.NotNull {
-		// not primary key & database is nullable
+		// not primary key & current database is non-nullable(to be nullable)
-		if !field.PrimaryKey && nullable {
+		if !field.PrimaryKey && !nullable {
-			alterColumn = true
-		}
-	}
-
-	// check unique
-	if unique, ok := columnType.Unique(); ok && unique != field.Unique {
-		// not primary key
-		if !field.PrimaryKey {
 			alterColumn = true
 		}
 	}
 
 	// check default value
-	if v, ok := columnType.DefaultValue(); ok && v != field.DefaultValue {
+	if !field.PrimaryKey {
-		// not primary key
+		currentDefaultNotNull := field.HasDefaultValue && (field.DefaultValueInterface != nil || !strings.EqualFold(field.DefaultValue, "NULL"))
-		if !field.PrimaryKey {
+		dv, dvNotNull := columnType.DefaultValue()
+		if dvNotNull && !currentDefaultNotNull {
+			// default value -> null
 			alterColumn = true
+		} else if !dvNotNull && currentDefaultNotNull {
+			// null -> default value
+			alterColumn = true
+		} else if currentDefaultNotNull || dvNotNull {
+			switch field.GORMDataType {
+			case schema.Time:
+				if !strings.EqualFold(strings.TrimSuffix(dv, "()"), strings.TrimSuffix(field.DefaultValue, "()")) {
+					alterColumn = true
+				}
+			case schema.Bool:
+				v1, _ := strconv.ParseBool(dv)
+				v2, _ := strconv.ParseBool(field.DefaultValue)
+				alterColumn = v1 != v2
+			default:
+				alterColumn = dv != field.DefaultValue
+			}
 		}
 	}
 
@@ -460,13 +574,39 @@ func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnTy
 		}
 	}
 
-	if alterColumn && !field.IgnoreMigration {
+	if alterColumn {
-		return m.DB.Migrator().AlterColumn(value, field.Name)
+		if err := m.DB.Migrator().AlterColumn(value, field.DBName); err != nil {
+			return err
+		}
+	}
+
+	if err := m.DB.Migrator().MigrateColumnUnique(value, field, columnType); err != nil {
+		return err
 	}
 
 	return nil
 }
 
+func (m Migrator) MigrateColumnUnique(value interface{}, field *schema.Field, columnType gorm.ColumnType) error {
+	unique, ok := columnType.Unique()
+	if !ok || field.PrimaryKey {
+		return nil // skip primary key
+	}
+	// By default, ColumnType's Unique is not affected by UniqueIndex, so we don't care about UniqueIndex.
+	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		// We're currently only receiving boolean values on `Unique` tag,
+		// so the UniqueConstraint name is fixed
+		constraint := m.DB.NamingStrategy.UniqueName(stmt.Table, field.DBName)
+		if unique && !field.Unique {
+			return m.DB.Migrator().DropConstraint(value, constraint)
+		}
+		if !unique && field.Unique {
+			return m.DB.Migrator().CreateConstraint(value, constraint)
+		}
+		return nil
+	})
+}
+
 // ColumnTypes return columnTypes []gorm.ColumnType and execErr error
 func (m Migrator) ColumnTypes(value interface{}) ([]gorm.ColumnType, error) {
 	columnTypes := make([]gorm.ColumnType, 0)
@@ -496,47 +636,76 @@ func (m Migrator) ColumnTypes(value interface{}) ([]gorm.ColumnType, error) {
 	return columnTypes, execErr
 }
 
-// CreateView create view
+// CreateView create view from Query in gorm.ViewOption.
+// Query in gorm.ViewOption is a [subquery]
+//
+//	// CREATE VIEW `user_view` AS SELECT * FROM `users` WHERE age > 20
+//	q := DB.Model(&User{}).Where("age > ?", 20)
+//	DB.Debug().Migrator().CreateView("user_view", gorm.ViewOption{Query: q})
+//
+//	// CREATE OR REPLACE VIEW `users_view` AS SELECT * FROM `users` WITH CHECK OPTION
+//	q := DB.Model(&User{})
+//	DB.Debug().Migrator().CreateView("user_view", gorm.ViewOption{Query: q, Replace: true, CheckOption: "WITH CHECK OPTION"})
+//
+// [subquery]: https://gorm.io/docs/advanced_query.html#SubQuery
 func (m Migrator) CreateView(name string, option gorm.ViewOption) error {
-	return gorm.ErrNotImplemented
+	if option.Query == nil {
+		return gorm.ErrSubQueryRequired
+	}
+
+	sql := new(strings.Builder)
+	sql.WriteString("CREATE ")
+	if option.Replace {
+		sql.WriteString("OR REPLACE ")
+	}
+	sql.WriteString("VIEW ")
+	m.QuoteTo(sql, name)
+	sql.WriteString(" AS ")
+
+	m.DB.Statement.AddVar(sql, option.Query)
+
+	if option.CheckOption != "" {
+		sql.WriteString(" ")
+		sql.WriteString(option.CheckOption)
+	}
+	return m.DB.Exec(m.Explain(sql.String(), m.DB.Statement.Vars...)).Error
 }
 
 // DropView drop view
 func (m Migrator) DropView(name string) error {
-	return gorm.ErrNotImplemented
+	return m.DB.Exec("DROP VIEW IF EXISTS ?", clause.Table{Name: name}).Error
-}
-
-func buildConstraint(constraint *schema.Constraint) (sql string, results []interface{}) {
-	sql = "CONSTRAINT ? FOREIGN KEY ? REFERENCES ??"
-	if constraint.OnDelete != "" {
-		sql += " ON DELETE " + constraint.OnDelete
-	}
-
-	if constraint.OnUpdate != "" {
-		sql += " ON UPDATE " + constraint.OnUpdate
-	}
-
-	var foreignKeys, references []interface{}
-	for _, field := range constraint.ForeignKeys {
-		foreignKeys = append(foreignKeys, clause.Column{Name: field.DBName})
-	}
-
-	for _, field := range constraint.References {
-		references = append(references, clause.Column{Name: field.DBName})
-	}
-	results = append(results, clause.Table{Name: constraint.Name}, foreignKeys, clause.Table{Name: constraint.ReferenceSchema.Table}, references)
-	return
 }
 
 // GuessConstraintAndTable guess statement's constraint and it's table based on name
-func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_ *schema.Constraint, _ *schema.Check, table string) {
+//
+// Deprecated: use GuessConstraintInterfaceAndTable instead.
+func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (*schema.Constraint, *schema.CheckConstraint, string) {
+	constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
+	switch c := constraint.(type) {
+	case *schema.Constraint:
+		return c, nil, table
+	case *schema.CheckConstraint:
+		return nil, c, table
+	default:
+		return nil, nil, table
+	}
+}
+
+// GuessConstraintInterfaceAndTable guess statement's constraint and it's table based on name
+// nolint:cyclop
+func (m Migrator) GuessConstraintInterfaceAndTable(stmt *gorm.Statement, name string) (_ schema.ConstraintInterface, table string) {
 	if stmt.Schema == nil {
-		return nil, nil, stmt.Table
+		return nil, stmt.Table
 	}
 
 	checkConstraints := stmt.Schema.ParseCheckConstraints()
 	if chk, ok := checkConstraints[name]; ok {
-		return nil, &chk, stmt.Table
+		return &chk, stmt.Table
+	}
+
+	uniqueConstraints := stmt.Schema.ParseUniqueConstraints()
+	if uni, ok := uniqueConstraints[name]; ok {
+		return &uni, stmt.Table
 	}
 
 	getTable := func(rel *schema.Relationship) string {
@@ -551,7 +720,7 @@ func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_
 
 	for _, rel := range stmt.Schema.Relationships.Relations {
 		if constraint := rel.ParseConstraint(); constraint != nil && constraint.Name == name {
-			return constraint, nil, getTable(rel)
+			return constraint, getTable(rel)
 		}
 	}
 
@@ -559,40 +728,39 @@ func (m Migrator) GuessConstraintAndTable(stmt *gorm.Statement, name string) (_
 		for k := range checkConstraints {
 			if checkConstraints[k].Field == field {
 				v := checkConstraints[k]
-				return nil, &v, stmt.Table
+				return &v, stmt.Table
+			}
+		}
+
+		for k := range uniqueConstraints {
+			if uniqueConstraints[k].Field == field {
+				v := uniqueConstraints[k]
+				return &v, stmt.Table
 			}
 		}
 
 		for _, rel := range stmt.Schema.Relationships.Relations {
 			if constraint := rel.ParseConstraint(); constraint != nil && rel.Field == field {
-				return constraint, nil, getTable(rel)
+				return constraint, getTable(rel)
 			}
 		}
 	}
 
-	return nil, nil, stmt.Schema.Table
+	return nil, stmt.Schema.Table
 }
 
 // CreateConstraint create constraint
 func (m Migrator) CreateConstraint(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		constraint, chk, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
-		if chk != nil {
-			return m.DB.Exec(
-				"ALTER TABLE ? ADD CONSTRAINT ? CHECK (?)",
-				m.CurrentTable(stmt), clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint},
-			).Error
-		}
-
 		if constraint != nil {
 			vars := []interface{}{clause.Table{Name: table}}
 			if stmt.TableExpr != nil {
 				vars[0] = stmt.TableExpr
 			}
-			sql, values := buildConstraint(constraint)
+			sql, values := constraint.Build()
 			return m.DB.Exec("ALTER TABLE ? ADD "+sql, append(vars, values...)...).Error
 		}
-
 		return nil
 	})
 }
@@ -600,11 +768,9 @@ func (m Migrator) CreateConstraint(value interface{}, name string) error {
 // DropConstraint drop constraint
 func (m Migrator) DropConstraint(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		constraint, chk, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
 		if constraint != nil {
-			name = constraint.Name
+			name = constraint.GetName()
-		} else if chk != nil {
-			name = chk.Name
 		}
 		return m.DB.Exec("ALTER TABLE ? DROP CONSTRAINT ?", clause.Table{Name: table}, clause.Column{Name: name}).Error
 	})
@@ -615,11 +781,9 @@ func (m Migrator) HasConstraint(value interface{}, name string) bool {
 	var count int64
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		currentDatabase := m.DB.Migrator().CurrentDatabase()
-		constraint, chk, table := m.GuessConstraintAndTable(stmt, name)
+		constraint, table := m.GuessConstraintInterfaceAndTable(stmt, name)
 		if constraint != nil {
-			name = constraint.Name
+			name = constraint.GetName()
-		} else if chk != nil {
-			name = chk.Name
 		}
 
 		return m.DB.Raw(
@@ -661,6 +825,9 @@ type BuildIndexOptionsInterface interface {
 // CreateIndex create index `name`
 func (m Migrator) CreateIndex(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
+		if stmt.Schema == nil {
+			return errors.New("failed to get schema")
+		}
 		if idx := stmt.Schema.LookIndex(name); idx != nil {
 			opts := m.DB.Migrator().(BuildIndexOptionsInterface).BuildIndexOptions(idx.Fields, stmt)
 			values := []interface{}{clause.Column{Name: idx.Name}, m.CurrentTable(stmt), opts}
@@ -693,8 +860,10 @@ func (m Migrator) CreateIndex(value interface{}, name string) error {
 // DropIndex drop index `name`
 func (m Migrator) DropIndex(value interface{}, name string) error {
 	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
-		if idx := stmt.Schema.LookIndex(name); idx != nil {
+		if stmt.Schema != nil {
-			name = idx.Name
+			if idx := stmt.Schema.LookIndex(name); idx != nil {
+				name = idx.Name
+			}
 		}
 
 		return m.DB.Exec("DROP INDEX ? ON ?", clause.Column{Name: name}, m.CurrentTable(stmt)).Error
@@ -706,8 +875,10 @@ func (m Migrator) HasIndex(value interface{}, name string) bool {
 	var count int64
 	m.RunWithValue(value, func(stmt *gorm.Statement) error {
 		currentDatabase := m.DB.Migrator().CurrentDatabase()
-		if idx := stmt.Schema.LookIndex(name); idx != nil {
+		if stmt.Schema != nil {
-			name = idx.Name
+			if idx := stmt.Schema.LookIndex(name); idx != nil {
+				name = idx.Name
+			}
 		}
 
 		return m.DB.Raw(
@@ -756,7 +927,8 @@ func (m Migrator) ReorderModels(values []interface{}, autoAdd bool) (results []i
 			Statement: &gorm.Statement{DB: m.DB, Dest: value},
 		}
 		beDependedOn := map[*schema.Schema]bool{}
-		if err := dep.Parse(value); err != nil {
+		// support for special table name
+		if err := dep.ParseWithSpecialTableName(value, m.DB.Statement.Table); err != nil {
 			m.DB.Logger.Error(context.Background(), "failed to parse value %#v, got error %v", value, err)
 		}
 		if _, ok := parsedSchemas[dep.Statement.Schema]; ok {
@@ -764,26 +936,31 @@ func (m Migrator) ReorderModels(values []interface{}, autoAdd bool) (results []i
 		}
 		parsedSchemas[dep.Statement.Schema] = true
 
-		for _, rel := range dep.Schema.Relationships.Relations {
+		if !m.DB.IgnoreRelationshipsWhenMigrating {
-			if c := rel.ParseConstraint(); c != nil && c.Schema == dep.Statement.Schema && c.Schema != c.ReferenceSchema {
+			for _, rel := range dep.Schema.Relationships.Relations {
-				dep.Depends = append(dep.Depends, c.ReferenceSchema)
+				if rel.Field.IgnoreMigration {
-			}
+					continue
+				}
+				if c := rel.ParseConstraint(); c != nil && c.Schema == dep.Statement.Schema && c.Schema != c.ReferenceSchema {
+					dep.Depends = append(dep.Depends, c.ReferenceSchema)
+				}
 
-			if rel.Type == schema.HasOne || rel.Type == schema.HasMany {
+				if rel.Type == schema.HasOne || rel.Type == schema.HasMany {
-				beDependedOn[rel.FieldSchema] = true
+					beDependedOn[rel.FieldSchema] = true
-			}
+				}
 
-			if rel.JoinTable != nil {
+				if rel.JoinTable != nil {
-				// append join value
+					// append join value
-				defer func(rel *schema.Relationship, joinValue interface{}) {
+					defer func(rel *schema.Relationship, joinValue interface{}) {
-					if !beDependedOn[rel.FieldSchema] {
+						if !beDependedOn[rel.FieldSchema] {
-						dep.Depends = append(dep.Depends, rel.FieldSchema)
+							dep.Depends = append(dep.Depends, rel.FieldSchema)
-					} else {
+						} else {
-						fieldValue := reflect.New(rel.FieldSchema.ModelType).Interface()
+							fieldValue := reflect.New(rel.FieldSchema.ModelType).Interface()
-						parseDependence(fieldValue, autoAdd)
+							parseDependence(fieldValue, autoAdd)
-					}
+						}
-					parseDependence(joinValue, autoAdd)
+						parseDependence(joinValue, autoAdd)
-				}(rel, reflect.New(rel.JoinTable.ModelType).Interface())
+					}(rel, reflect.New(rel.JoinTable.ModelType).Interface())
+				}
 			}
 		}
 
@@ -840,3 +1017,18 @@ func (m Migrator) CurrentTable(stmt *gorm.Statement) interface{} {
 	}
 	return clause.Table{Name: stmt.Table}
 }
+
+// GetIndexes return Indexes []gorm.Index and execErr error
+func (m Migrator) GetIndexes(dst interface{}) ([]gorm.Index, error) {
+	return nil, errors.New("not support")
+}
+
+// GetTypeAliases return database type aliases
+func (m Migrator) GetTypeAliases(databaseTypeName string) []string {
+	return nil
+}
+
+// TableType return tableType gorm.TableType and execErr error
+func (m Migrator) TableType(dst interface{}) (gorm.TableType, error) {
+	return nil, errors.New("not support")
+}

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

@@ -3,70 +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
+	Stmts stmt_store.Store
-	PreparedSQL []string
+	Mux   *sync.RWMutex
-	Mux         *sync.RWMutex
 	ConnPool
 }
 
-func (db *PreparedStmtDB) GetDBConn() (*sql.DB, error) {
+// NewPreparedStmtDB creates and initializes a new instance of PreparedStmtDB.
-	if dbConnector, ok := db.ConnPool.(GetDBConnector); ok && dbConnector != nil {
+//
-		return dbConnector.GetDBConn()
+// 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.
 	}
+}
 
+// 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 _, query := range db.PreparedSQL {
+	for _, key := range db.Stmts.Keys() {
-		if stmt, ok := db.Stmts[query]; ok {
+		db.Stmts.Delete(key)
-			delete(db.Stmts, query)
-			go stmt.Close()
-		}
 	}
 }
 
-func (db *PreparedStmtDB) prepare(ctx context.Context, conn ConnPool, isTransaction bool, query string) (Stmt, error) {
+// 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) {
+	if db.Stmts != nil {
-		db.Mux.RUnlock()
+		if stmt, ok := db.Stmts.Get(query); ok && (!stmt.Transaction || isTransaction) {
-		return stmt, nil
+			db.Mux.RUnlock()
+			return stmt, stmt.Error()
+		}
 	}
 	db.Mux.RUnlock()
 
+	// retry
 	db.Mux.Lock()
-	defer db.Mux.Unlock()
+	if db.Stmts != nil {
-
+		if stmt, ok := db.Stmts.Get(query); ok && (!stmt.Transaction || isTransaction) {
-	// double check
+			db.Mux.Unlock()
-	if stmt, ok := db.Stmts[query]; ok && (!stmt.Transaction || isTransaction) {
+			return stmt, stmt.Error()
-		return stmt, nil
+		}
-	} else if ok {
-		go stmt.Close()
 	}
 
-	stmt, err := conn.PrepareContext(ctx, query)
+	return db.Stmts.New(ctx, query, isTransaction, conn, db.Mux)
-	if err == nil {
-		db.Stmts[query] = Stmt{Stmt: stmt, Transaction: isTransaction}
-		db.PreparedSQL = append(db.PreparedSQL, query)
-	}
-
-	return db.Stmts[query], err
 }
 
 func (db *PreparedStmtDB) BeginTx(ctx context.Context, opt *sql.TxOptions) (ConnPool, error) {
@@ -74,6 +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
 }
 
@@ -81,11 +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 {
+		if errors.Is(err, driver.ErrBadConn) {
-			db.Mux.Lock()
+			db.Stmts.Delete(query)
-			defer db.Mux.Unlock()
-			go stmt.Close()
-			delete(db.Stmts, query)
 		}
 	}
 	return result, err
@@ -95,12 +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 {
+		if errors.Is(err, driver.ErrBadConn) {
-			db.Mux.Lock()
+			db.Stmts.Delete(query)
-			defer db.Mux.Unlock()
-
-			go stmt.Close()
-			delete(db.Stmts, query)
 		}
 	}
 	return rows, err
@@ -114,20 +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 {
 	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
@@ -137,12 +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 {
+		if errors.Is(err, driver.ErrBadConn) {
-			tx.PreparedStmtDB.Mux.Lock()
+			tx.PreparedStmtDB.Stmts.Delete(query)
-			defer tx.PreparedStmtDB.Mux.Unlock()
-
-			go stmt.Close()
-			delete(tx.PreparedStmtDB.Stmts, query)
 		}
 	}
 	return result, err
@@ -152,12 +182,8 @@ func (tx *PreparedStmtTX) QueryContext(ctx context.Context, query string, args .
 	stmt, err := tx.PreparedStmtDB.prepare(ctx, tx.Tx, true, query)
 	if err == nil {
 		rows, err = tx.Tx.StmtContext(ctx, stmt.Stmt).QueryContext(ctx, args...)
-		if err != nil {
+		if errors.Is(err, driver.ErrBadConn) {
-			tx.PreparedStmtDB.Mux.Lock()
+			tx.PreparedStmtDB.Stmts.Delete(query)
-			defer tx.PreparedStmtDB.Mux.Unlock()
-
-			go stmt.Close()
-			delete(tx.PreparedStmtDB.Stmts, query)
 		}
 	}
 	return rows, err
@@ -170,3 +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

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"gorm.io/gorm/schema"
+	"gorm.io/gorm/utils"
 )
 
 // prepareValues prepare values slice
@@ -15,7 +16,7 @@ func prepareValues(values []interface{}, db *DB, columnTypes []*sql.ColumnType,
 	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{})
@@ -23,7 +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{})
 			}
@@ -50,7 +51,7 @@ func scanIntoMap(mapValue map[string]interface{}, values []interface{}, columns
 	}
 }
 
-func (db *DB) scanIntoStruct(rows Rows, reflectValue reflect.Value, values []interface{}, fields []*schema.Field, joinFields [][2]*schema.Field) {
+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()
@@ -65,26 +66,49 @@ func (db *DB) scanIntoStruct(rows Rows, reflectValue reflect.Value, values []int
 
 	db.RowsAffected++
 	db.AddError(rows.Scan(values...))
-
+	joinedNestedSchemaMap := make(map[string]interface{})
 	for idx, field := range fields {
-		if field != nil {
+		if field == nil {
-			if len(joinFields) == 0 || joinFields[idx][0] == nil {
+			continue
-				db.AddError(field.Set(db.Statement.Context, reflectValue, values[idx]))
+		}
-			} else {
-				relValue := joinFields[idx][0].ReflectValueOf(db.Statement.Context, reflectValue)
-				if relValue.Kind() == reflect.Ptr && relValue.IsNil() {
-					if value := reflect.ValueOf(values[idx]).Elem(); value.Kind() == reflect.Ptr && value.IsNil() {
-						return
-					}
 
-					relValue.Set(reflect.New(relValue.Type().Elem()))
+		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
+					}
 				}
-				db.AddError(joinFields[idx][1].Set(db.Statement.Context, relValue, values[idx]))
+				currentReflectValue = relValue
 			}
 
-			// release data to pool
+			if !isNilPtrValue { // ignore if value is nil
-			field.NewValuePool.Put(values[idx])
+				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])
 	}
 }
 
@@ -108,6 +132,15 @@ func Scan(rows Rows, db *DB, mode ScanMode) {
 		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) {
@@ -156,11 +189,10 @@ func Scan(rows Rows, db *DB, mode ScanMode) {
 		}
 	default:
 		var (
-			fields             = make([]*schema.Field, len(columns))
+			fields       = make([]*schema.Field, len(columns))
-			selectedColumnsMap = make(map[string]int, len(columns))
+			joinFields   [][]*schema.Field
-			joinFields         [][2]*schema.Field
+			sch          = db.Statement.Schema
-			sch                = db.Statement.Schema
+			reflectValue = db.Statement.ReflectValue
-			reflectValue       = db.Statement.ReflectValue
 		)
 
 		if reflectValue.Kind() == reflect.Interface {
@@ -193,35 +225,61 @@ func Scan(rows Rows, db *DB, mode ScanMode) {
 
 			// Not Pluck
 			if sch != nil {
+				matchedFieldCount := make(map[string]int, len(columns))
 				for idx, column := range columns {
 					if field := sch.LookUpField(column); field != nil && field.Readable {
-						if curIndex, ok := selectedColumnsMap[column]; ok {
+						fields[idx] = field
-							for fieldIndex, selectField := range sch.Fields[curIndex:] {
+						if count, ok := matchedFieldCount[column]; ok {
+							// handle duplicate fields
+							for _, selectField := range sch.Fields {
 								if selectField.DBName == column && selectField.Readable {
-									selectedColumnsMap[column] = curIndex + fieldIndex + 1
+									if count == 0 {
-									fields[idx] = selectField
+										matchedFieldCount[column]++
-									break
+										fields[idx] = selectField
+										break
+									}
+									count--
 								}
 							}
 						} else {
-							fields[idx] = field
+							matchedFieldCount[column] = 1
-							selectedColumnsMap[column] = idx
 						}
-					} else if names := strings.Split(column, "__"); len(names) > 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 {
-							if field := rel.FieldSchema.LookUpField(strings.Join(names[1:], "__")); field != nil && field.Readable {
+							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{}
+						var val interface{}
+						values[idx] = &val
 					}
 				}
 			}
@@ -229,11 +287,24 @@ func Scan(rows Rows, db *DB, mode ScanMode) {
 
 		switch reflectValue.Kind() {
 		case reflect.Slice, reflect.Array:
-			var elem reflect.Value
+			var (
+				elem        reflect.Value
+				isArrayKind = reflectValue.Kind() == reflect.Array
+			)
 
 			if !update || reflectValue.Len() == 0 {
 				update = false
-				db.Statement.ReflectValue.Set(reflect.MakeSlice(reflectValue.Type(), 0, 20))
+				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() {
@@ -260,10 +331,15 @@ func Scan(rows Rows, db *DB, mode ScanMode) {
 				db.scanIntoStruct(rows, elem, values, fields, joinFields)
 
 				if !update {
-					if isPtr {
+					if !isPtr {
-						reflectValue = reflect.Append(reflectValue, elem)
+						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.Elem())
+						reflectValue = reflect.Append(reflectValue, elem)
 					}
 				}
 			}
@@ -273,6 +349,9 @@ func Scan(rows Rows, db *DB, mode ScanMode) {
 			}
 		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:

schema/check.go

@@ -1,35 +0,0 @@
-package schema
-
-import (
-	"regexp"
-	"strings"
-)
-
-// reg match english letters and midline
-var 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 {
-	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.go

@@ -49,11 +49,14 @@ const (
 	Bytes  DataType = "bytes"
 )
 
+const DefaultAutoIncrementIncrement int64 = 1
+
 // Field is the representation of model schema's field
 type Field struct {
 	Name                   string
 	DBName                 string
 	BindNames              []string
+	EmbeddedBindNames      []string
 	DataType               DataType
 	GORMDataType           DataType
 	PrimaryKey             bool
@@ -87,6 +90,16 @@ type Field struct {
 	Set                    func(context.Context, reflect.Value, interface{}) error
 	Serializer             SerializerInterface
 	NewValuePool           FieldNewValuePool
+
+	// In some db (e.g. MySQL), Unique and UniqueIndex are indistinguishable.
+	// When a column has a (not Mul) UniqueIndex, Migrator always reports its gorm.ColumnType is Unique.
+	// It causes field unnecessarily migration.
+	// Therefore, we need to record the UniqueIndex on this column (exclude Mul UniqueIndex) for MigrateColumnUnique.
+	UniqueIndex string
+}
+
+func (field *Field) BindName() string {
+	return strings.Join(field.BindNames, ".")
 }
 
 // ParseField parses reflect.StructField to Field
@@ -100,6 +113,7 @@ func (schema *Schema) ParseField(fieldStruct reflect.StructField) *Field {
 		Name:                   fieldStruct.Name,
 		DBName:                 tagSetting["COLUMN"],
 		BindNames:              []string{fieldStruct.Name},
+		EmbeddedBindNames:      []string{fieldStruct.Name},
 		FieldType:              fieldStruct.Type,
 		IndirectFieldType:      fieldStruct.Type,
 		StructField:            fieldStruct,
@@ -115,7 +129,7 @@ func (schema *Schema) ParseField(fieldStruct reflect.StructField) *Field {
 		NotNull:                utils.CheckTruth(tagSetting["NOT NULL"], tagSetting["NOTNULL"]),
 		Unique:                 utils.CheckTruth(tagSetting["UNIQUE"]),
 		Comment:                tagSetting["COMMENT"],
-		AutoIncrementIncrement: 1,
+		AutoIncrementIncrement: DefaultAutoIncrementIncrement,
 	}
 
 	for field.IndirectFieldType.Kind() == reflect.Ptr {
@@ -174,7 +188,7 @@ func (schema *Schema) ParseField(fieldStruct reflect.StructField) *Field {
 		field.DataType = String
 		field.Serializer = v
 	} else {
-		var serializerName = field.TagSettings["JSON"]
+		serializerName := field.TagSettings["JSON"]
 		if serializerName == "" {
 			serializerName = field.TagSettings["SERIALIZER"]
 		}
@@ -304,9 +318,10 @@ func (schema *Schema) ParseField(fieldStruct reflect.StructField) *Field {
 	}
 
 	if val, ok := field.TagSettings["TYPE"]; ok {
-		switch DataType(strings.ToLower(val)) {
+		lowerVal := DataType(strings.ToLower(val))
+		switch lowerVal {
 		case Bool, Int, Uint, Float, String, Time, Bytes:
-			field.DataType = DataType(strings.ToLower(val))
+			field.DataType = lowerVal
 		default:
 			field.DataType = DataType(val)
 		}
@@ -391,6 +406,9 @@ func (schema *Schema) ParseField(fieldStruct reflect.StructField) *Field {
 				ef.Schema = schema
 				ef.OwnerSchema = field.EmbeddedSchema
 				ef.BindNames = append([]string{fieldStruct.Name}, ef.BindNames...)
+				if _, ok := field.TagSettings["EMBEDDED"]; ok || !fieldStruct.Anonymous {
+					ef.EmbeddedBindNames = append([]string{fieldStruct.Name}, ef.EmbeddedBindNames...)
+				}
 				// index is negative means is pointer
 				if field.FieldType.Kind() == reflect.Struct {
 					ef.StructField.Index = append([]int{fieldStruct.Index[0]}, ef.StructField.Index...)
@@ -403,18 +421,14 @@ func (schema *Schema) ParseField(fieldStruct reflect.StructField) *Field {
 				}
 
 				if ef.PrimaryKey {
-					if val, ok := ef.TagSettings["PRIMARYKEY"]; ok && utils.CheckTruth(val) {
+					if !utils.CheckTruth(ef.TagSettings["PRIMARYKEY"], ef.TagSettings["PRIMARY_KEY"]) {
-						ef.PrimaryKey = true
-					} else if val, ok := ef.TagSettings["PRIMARY_KEY"]; ok && utils.CheckTruth(val) {
-						ef.PrimaryKey = true
-					} else {
 						ef.PrimaryKey = false
 
 						if val, ok := ef.TagSettings["AUTOINCREMENT"]; !ok || !utils.CheckTruth(val) {
 							ef.AutoIncrement = false
 						}
 
-						if ef.DefaultValue == "" {
+						if !ef.AutoIncrement && ef.DefaultValue == "" {
 							ef.HasDefaultValue = false
 						}
 					}
@@ -434,21 +448,30 @@ func (schema *Schema) ParseField(fieldStruct reflect.StructField) *Field {
 }
 
 // create valuer, setter when parse struct
-func (field *Field) setupValuerAndSetter() {
+func (field *Field) setupValuerAndSetter(modelType reflect.Type) {
 	// Setup NewValuePool
 	field.setupNewValuePool()
 
 	// ValueOf returns field's value and if it is zero
 	fieldIndex := field.StructField.Index[0]
 	switch {
-	case len(field.StructField.Index) == 1 && fieldIndex > 0:
+	case len(field.StructField.Index) == 1 && fieldIndex >= 0:
-		field.ValueOf = func(ctx context.Context, value reflect.Value) (interface{}, bool) {
+		field.ValueOf = func(ctx context.Context, v reflect.Value) (interface{}, bool) {
-			fieldValue := reflect.Indirect(value).Field(fieldIndex)
+			v = reflect.Indirect(v)
+			if v.Type() != modelType {
+				fieldValue := v.FieldByName(field.Name)
+				return fieldValue.Interface(), fieldValue.IsZero()
+			}
+			fieldValue := v.Field(fieldIndex)
 			return fieldValue.Interface(), fieldValue.IsZero()
 		}
 	default:
 		field.ValueOf = func(ctx context.Context, v reflect.Value) (interface{}, bool) {
 			v = reflect.Indirect(v)
+			if v.Type() != modelType {
+				fieldValue := v.FieldByName(field.Name)
+				return fieldValue.Interface(), fieldValue.IsZero()
+			}
 			for _, fieldIdx := range field.StructField.Index {
 				if fieldIdx >= 0 {
 					v = v.Field(fieldIdx)
@@ -472,9 +495,6 @@ func (field *Field) setupValuerAndSetter() {
 		oldValuerOf := field.ValueOf
 		field.ValueOf = func(ctx context.Context, v reflect.Value) (interface{}, bool) {
 			value, zero := oldValuerOf(ctx, v)
-			if zero {
-				return value, zero
-			}
 
 			s, ok := value.(SerializerValuerInterface)
 			if !ok {
@@ -487,19 +507,26 @@ func (field *Field) setupValuerAndSetter() {
 				Destination:     v,
 				Context:         ctx,
 				fieldValue:      value,
-			}, false
+			}, zero
 		}
 	}
 
 	// ReflectValueOf returns field's reflect value
 	switch {
-	case len(field.StructField.Index) == 1 && fieldIndex > 0:
+	case len(field.StructField.Index) == 1 && fieldIndex >= 0:
-		field.ReflectValueOf = func(ctx context.Context, value reflect.Value) reflect.Value {
+		field.ReflectValueOf = func(ctx context.Context, v reflect.Value) reflect.Value {
-			return reflect.Indirect(value).Field(fieldIndex)
+			v = reflect.Indirect(v)
+			if v.Type() != modelType {
+				return v.FieldByName(field.Name)
+			}
+			return v.Field(fieldIndex)
 		}
 	default:
 		field.ReflectValueOf = func(ctx context.Context, v reflect.Value) reflect.Value {
 			v = reflect.Indirect(v)
+			if v.Type() != modelType {
+				return v.FieldByName(field.Name)
+			}
 			for idx, fieldIdx := range field.StructField.Index {
 				if fieldIdx >= 0 {
 					v = v.Field(fieldIdx)
@@ -528,6 +555,9 @@ func (field *Field) setupValuerAndSetter() {
 			reflectValType := reflectV.Type()
 
 			if reflectValType.AssignableTo(field.FieldType) {
+				if reflectV.Kind() == reflect.Ptr && reflectV.Elem().Kind() == reflect.Ptr {
+					reflectV = reflect.Indirect(reflectV)
+				}
 				field.ReflectValueOf(ctx, value).Set(reflectV)
 				return
 			} else if reflectValType.ConvertibleTo(field.FieldType) {
@@ -604,6 +634,22 @@ func (field *Field) setupValuerAndSetter() {
 				if data != nil && *data != nil {
 					field.ReflectValueOf(ctx, value).SetInt(**data)
 				}
+			case **int:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetInt(int64(**data))
+				}
+			case **int8:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetInt(int64(**data))
+				}
+			case **int16:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetInt(int64(**data))
+				}
+			case **int32:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetInt(int64(**data))
+				}
 			case int64:
 				field.ReflectValueOf(ctx, value).SetInt(data)
 			case int:
@@ -640,7 +686,7 @@ func (field *Field) setupValuerAndSetter() {
 				if field.AutoCreateTime == UnixNanosecond || field.AutoUpdateTime == UnixNanosecond {
 					field.ReflectValueOf(ctx, value).SetInt(data.UnixNano())
 				} else if field.AutoCreateTime == UnixMillisecond || field.AutoUpdateTime == UnixMillisecond {
-					field.ReflectValueOf(ctx, value).SetInt(data.UnixNano() / 1e6)
+					field.ReflectValueOf(ctx, value).SetInt(data.UnixMilli())
 				} else {
 					field.ReflectValueOf(ctx, value).SetInt(data.Unix())
 				}
@@ -649,7 +695,7 @@ func (field *Field) setupValuerAndSetter() {
 					if field.AutoCreateTime == UnixNanosecond || field.AutoUpdateTime == UnixNanosecond {
 						field.ReflectValueOf(ctx, value).SetInt(data.UnixNano())
 					} else if field.AutoCreateTime == UnixMillisecond || field.AutoUpdateTime == UnixMillisecond {
-						field.ReflectValueOf(ctx, value).SetInt(data.UnixNano() / 1e6)
+						field.ReflectValueOf(ctx, value).SetInt(data.UnixMilli())
 					} else {
 						field.ReflectValueOf(ctx, value).SetInt(data.Unix())
 					}
@@ -668,6 +714,22 @@ func (field *Field) setupValuerAndSetter() {
 				if data != nil && *data != nil {
 					field.ReflectValueOf(ctx, value).SetUint(**data)
 				}
+			case **uint:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetUint(uint64(**data))
+				}
+			case **uint8:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetUint(uint64(**data))
+				}
+			case **uint16:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetUint(uint64(**data))
+				}
+			case **uint32:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetUint(uint64(**data))
+				}
 			case uint64:
 				field.ReflectValueOf(ctx, value).SetUint(data)
 			case uint:
@@ -698,7 +760,7 @@ func (field *Field) setupValuerAndSetter() {
 				if field.AutoCreateTime == UnixNanosecond || field.AutoUpdateTime == UnixNanosecond {
 					field.ReflectValueOf(ctx, value).SetUint(uint64(data.UnixNano()))
 				} else if field.AutoCreateTime == UnixMillisecond || field.AutoUpdateTime == UnixMillisecond {
-					field.ReflectValueOf(ctx, value).SetUint(uint64(data.UnixNano() / 1e6))
+					field.ReflectValueOf(ctx, value).SetUint(uint64(data.UnixMilli()))
 				} else {
 					field.ReflectValueOf(ctx, value).SetUint(uint64(data.Unix()))
 				}
@@ -720,6 +782,10 @@ func (field *Field) setupValuerAndSetter() {
 				if data != nil && *data != nil {
 					field.ReflectValueOf(ctx, value).SetFloat(**data)
 				}
+			case **float32:
+				if data != nil && *data != nil {
+					field.ReflectValueOf(ctx, value).SetFloat(float64(**data))
+				}
 			case float64:
 				field.ReflectValueOf(ctx, value).SetFloat(data)
 			case float32:
@@ -810,7 +876,7 @@ func (field *Field) setupValuerAndSetter() {
 			field.Set = func(ctx context.Context, value reflect.Value, v interface{}) error {
 				switch data := v.(type) {
 				case **time.Time:
-					if data != nil {
+					if data != nil && *data != nil {
 						field.ReflectValueOf(ctx, value).Set(reflect.ValueOf(*data))
 					}
 				case time.Time:
@@ -846,14 +912,12 @@ func (field *Field) setupValuerAndSetter() {
 					reflectV := reflect.ValueOf(v)
 					if !reflectV.IsValid() {
 						field.ReflectValueOf(ctx, value).Set(reflect.New(field.FieldType).Elem())
+					} else if reflectV.Kind() == reflect.Ptr && reflectV.IsNil() {
+						return
 					} else if reflectV.Type().AssignableTo(field.FieldType) {
 						field.ReflectValueOf(ctx, value).Set(reflectV)
 					} else if reflectV.Kind() == reflect.Ptr {
-						if reflectV.IsNil() || !reflectV.IsValid() {
+						return field.Set(ctx, value, reflectV.Elem().Interface())
-							field.ReflectValueOf(ctx, value).Set(reflect.New(field.FieldType).Elem())
-						} else {
-							return field.Set(ctx, value, reflectV.Elem().Interface())
-						}
 					} else {
 						fieldValue := field.ReflectValueOf(ctx, value)
 						if fieldValue.IsNil() {
@@ -874,14 +938,12 @@ func (field *Field) setupValuerAndSetter() {
 					reflectV := reflect.ValueOf(v)
 					if !reflectV.IsValid() {
 						field.ReflectValueOf(ctx, value).Set(reflect.New(field.FieldType).Elem())
+					} else if reflectV.Kind() == reflect.Ptr && reflectV.IsNil() {
+						return
 					} else if reflectV.Type().AssignableTo(field.FieldType) {
 						field.ReflectValueOf(ctx, value).Set(reflectV)
 					} else if reflectV.Kind() == reflect.Ptr {
-						if reflectV.IsNil() || !reflectV.IsValid() {
+						return field.Set(ctx, value, reflectV.Elem().Interface())
-							field.ReflectValueOf(ctx, value).Set(reflect.New(field.FieldType).Elem())
-						} else {
-							return field.Set(ctx, value, reflectV.Elem().Interface())
-						}
 					} else {
 						if valuer, ok := v.(driver.Valuer); ok {
 							v, _ = valuer.Value()
@@ -910,6 +972,8 @@ func (field *Field) setupValuerAndSetter() {
 			sameElemType = field.FieldType == reflect.ValueOf(field.Serializer).Type().Elem()
 		}
 
+		serializerValue := reflect.Indirect(reflect.ValueOf(field.Serializer))
+		serializerType := serializerValue.Type()
 		field.Set = func(ctx context.Context, value reflect.Value, v interface{}) (err error) {
 			if s, ok := v.(*serializer); ok {
 				if s.fieldValue != nil {
@@ -917,11 +981,12 @@ func (field *Field) setupValuerAndSetter() {
 				} else if err = s.Serializer.Scan(ctx, field, value, s.value); err == nil {
 					if sameElemType {
 						field.ReflectValueOf(ctx, value).Set(reflect.ValueOf(s.Serializer).Elem())
-						s.Serializer = reflect.New(reflect.Indirect(reflect.ValueOf(field.Serializer)).Type()).Interface().(SerializerInterface)
 					} else if sameType {
 						field.ReflectValueOf(ctx, value).Set(reflect.ValueOf(s.Serializer))
-						s.Serializer = reflect.New(reflect.Indirect(reflect.ValueOf(field.Serializer)).Type()).Interface().(SerializerInterface)
 					}
+					si := reflect.New(serializerType)
+					si.Elem().Set(serializerValue)
+					s.Serializer = si.Interface().(SerializerInterface)
 				}
 			} else {
 				err = oldFieldSetter(ctx, value, v)
@@ -932,41 +997,22 @@ func (field *Field) setupValuerAndSetter() {
 }
 
 func (field *Field) setupNewValuePool() {
-	var fieldValue = reflect.New(field.FieldType).Interface()
 	if field.Serializer != nil {
+		serializerValue := reflect.Indirect(reflect.ValueOf(field.Serializer))
+		serializerType := serializerValue.Type()
 		field.NewValuePool = &sync.Pool{
 			New: func() interface{} {
+				si := reflect.New(serializerType)
+				si.Elem().Set(serializerValue)
 				return &serializer{
 					Field:      field,
-					Serializer: reflect.New(reflect.Indirect(reflect.ValueOf(field.Serializer)).Type()).Interface().(SerializerInterface),
+					Serializer: si.Interface().(SerializerInterface),
 				}
 			},
 		}
-	} else if _, ok := fieldValue.(sql.Scanner); !ok {
-		field.setupDefaultNewValuePool()
 	}
 
 	if field.NewValuePool == nil {
-		field.NewValuePool = poolInitializer(reflect.PtrTo(field.IndirectFieldType))
+		field.NewValuePool = poolInitializer(reflect.PointerTo(field.IndirectFieldType))
-	}
-}
-
-func (field *Field) setupDefaultNewValuePool() {
-	// set default NewValuePool
-	switch field.IndirectFieldType.Kind() {
-	case reflect.String:
-		field.NewValuePool = stringPool
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		field.NewValuePool = intPool
-	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
-		field.NewValuePool = uintPool
-	case reflect.Float32, reflect.Float64:
-		field.NewValuePool = floatPool
-	case reflect.Bool:
-		field.NewValuePool = boolPool
-	default:
-		if field.IndirectFieldType == TimeReflectType {
-			field.NewValuePool = timePool
-		}
 	}
 }

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
+	Option  string        // WITH PARSER parser_name
-	Fields  []IndexOption
+	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 {
+func (schema *Schema) ParseIndexes() []*Index {
-	indexes := map[string]Index{}
+	indexesByName := map[string]*Index{}
+	indexes := []*Index{}
 
 	for _, field := range schema.Fields {
 		if field.TagSettings["INDEX"] != "" || field.TagSettings["UNIQUEINDEX"] != "" {
-			for _, index := range parseFieldIndexes(field) {
+			fieldIndexes, err := parseFieldIndexes(field)
-				idx := indexes[index.Name]
+			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
 				}
 			}
 		}
@@ -82,7 +96,7 @@ 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, ":")
@@ -91,7 +105,7 @@ func parseFieldIndexes(field *Field) (indexes []Index) {
 				var (
 					name       string
 					tag        = strings.Join(v[1:], ":")
-					idx        = strings.Index(tag, ",")
+					idx        = strings.IndexByte(tag, ',')
 					tagSetting = strings.Join(strings.Split(tag, ",")[1:], ",")
 					settings   = ParseTagSetting(tagSetting, ",")
 					length, _  = strconv.Atoi(settings["LENGTH"])
@@ -101,12 +115,22 @@ func parseFieldIndexes(field *Field) (indexes []Index) {
 					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"] != "" {
@@ -131,12 +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 {
@@ -19,6 +19,40 @@ type UserIndex struct {
 	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) {
@@ -27,17 +61,17 @@ func TestParseIndex(t *testing.T) {
 		t.Fatalf("failed to parse user index, got error %v", err)
 	}
 
-	results := map[string]schema.Index{
+	results := []*schema.Index{
-		"idx_user_indices_name": {
+		{
 			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'",
@@ -48,19 +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",
@@ -70,53 +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"}}},
 		},
-		"type": {
+		{
 			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 {
+func TestParseIndexWithUniqueIndexAndUnique(t *testing.T) {
-		v, ok := indices[k]
+	type IndexTest struct {
-		if !ok {
+		FieldA string `gorm:"unique;index"` // unique and index
-			t.Fatalf("Failed to found index %v from parsed indices %+v", k, indices)
+		FieldB string `gorm:"unique"`       // unique
-		}
 
-		for _, name := range []string{"Name", "Class", "Type", "Where", "Comment", "Option"} {
+		FieldC string `gorm:"index:,unique"`     // uniqueIndex
-			if reflect.ValueOf(result).FieldByName(name).Interface() != reflect.ValueOf(v).FieldByName(name).Interface() {
+		FieldD string `gorm:"uniqueIndex;index"` // uniqueIndex and index
-				t.Errorf(
+
-					"index %v %v should equal, expects %v, got %v",
+		FieldE1 string `gorm:"uniqueIndex:uniq_field_e1_e2"` // mul uniqueIndex
-					k, name, reflect.ValueOf(result).FieldByName(name).Interface(), reflect.ValueOf(v).FieldByName(name).Interface(),
+		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 i, ef := range ei.Fields {
-
+				af := ai.Fields[i]
-		for idx, ef := range result.Fields {
+				tests.AssertObjEqual(t, af, ef, "Name", "Unique", "UniqueIndex", "Expression", "Sort", "Collate", "Length", "NotNull")
-			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 _, 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

@@ -4,6 +4,12 @@ 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

schema/naming.go

@@ -8,6 +8,8 @@ import (
 	"unicode/utf8"
 
 	"github.com/jinzhu/inflection"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
 )
 
 // Namer namer interface
@@ -19,6 +21,7 @@ type Namer interface {
 	RelationshipFKName(Relationship) string
 	CheckerName(table, column string) string
 	IndexName(table, column string) string
+	UniqueName(table, column string) string
 }
 
 // Replacer replacer interface like strings.Replacer
@@ -26,12 +29,15 @@ type Replacer interface {
 	Replace(name string) string
 }
 
+var _ Namer = (*NamingStrategy)(nil)
+
 // NamingStrategy tables, columns naming strategy
 type NamingStrategy struct {
-	TablePrefix   string
+	TablePrefix         string
-	SingularTable bool
+	SingularTable       bool
-	NameReplacer  Replacer
+	NameReplacer        Replacer
-	NoLowerCase   bool
+	NoLowerCase         bool
+	IdentifierMaxLength int
 }
 
 // TableName convert string to table name
@@ -84,17 +90,26 @@ func (ns NamingStrategy) IndexName(table, column string) string {
 	return ns.formatName("idx", table, ns.toDBName(column))
 }
 
+// UniqueName generate unique constraint name
+func (ns NamingStrategy) UniqueName(table, column string) string {
+	return ns.formatName("uni", table, ns.toDBName(column))
+}
+
 func (ns NamingStrategy) formatName(prefix, table, name string) string {
 	formattedName := strings.ReplaceAll(strings.Join([]string{
 		prefix, table, name,
 	}, "_"), ".", "_")
 
-	if utf8.RuneCountInString(formattedName) > 64 {
+	if ns.IdentifierMaxLength == 0 {
+		ns.IdentifierMaxLength = 64
+	}
+
+	if utf8.RuneCountInString(formattedName) > ns.IdentifierMaxLength {
 		h := sha1.New()
 		h.Write([]byte(formattedName))
 		bs := h.Sum(nil)
 
-		formattedName = formattedName[0:56] + hex.EncodeToString(bs)[:8]
+		formattedName = formattedName[0:ns.IdentifierMaxLength-8] + hex.EncodeToString(bs)[:8]
 	}
 	return formattedName
 }
@@ -108,7 +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...)
 }
@@ -173,9 +188,9 @@ func (ns NamingStrategy) toDBName(name string) string {
 }
 
 func (ns NamingStrategy) toSchemaName(name string) string {
-	result := strings.ReplaceAll(strings.Title(strings.ReplaceAll(name, "_", " ")), " ", "")
+	result := strings.ReplaceAll(cases.Title(language.Und, cases.NoLower).String(strings.ReplaceAll(name, "_", " ")), " ", "")
 	for _, initialism := range commonInitialisms {
-		result = regexp.MustCompile(strings.Title(strings.ToLower(initialism))+"([A-Z]|$|_)").ReplaceAllString(result, initialism+"$1")
+		result = regexp.MustCompile(cases.Title(language.Und, cases.NoLower).String(strings.ToLower(initialism))+"([A-Z]|$|_)").ReplaceAllString(result, initialism+"$1")
 	}
 	return result
 }

schema/naming_test.go

@@ -189,8 +189,17 @@ func TestCustomReplacerWithNoLowerCase(t *testing.T) {
 	}
 }
 
+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{}
+	ns := NamingStrategy{IdentifierMaxLength: 64}
 
 	formattedName := ns.formatName("prefix", "table", "thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVeryLongString")
 	if formattedName != "prefix_table_thisIsAVeryVeryVeryVeryVeryVeryVeryVeryVery180f2c67" {

schema/pool.go

@@ -3,54 +3,11 @@ package schema
 import (
 	"reflect"
 	"sync"
-	"time"
 )
 
 // sync pools
 var (
-	normalPool sync.Map
+	normalPool      sync.Map
-	stringPool = &sync.Pool{
-		New: func() interface{} {
-			var v string
-			ptrV := &v
-			return &ptrV
-		},
-	}
-	intPool = &sync.Pool{
-		New: func() interface{} {
-			var v int64
-			ptrV := &v
-			return &ptrV
-		},
-	}
-	uintPool = &sync.Pool{
-		New: func() interface{} {
-			var v uint64
-			ptrV := &v
-			return &ptrV
-		},
-	}
-	floatPool = &sync.Pool{
-		New: func() interface{} {
-			var v float64
-			ptrV := &v
-			return &ptrV
-		},
-	}
-	boolPool = &sync.Pool{
-		New: func() interface{} {
-			var v bool
-			ptrV := &v
-			return &ptrV
-		},
-	}
-	timePool = &sync.Pool{
-		New: func() interface{} {
-			var v time.Time
-			ptrV := &v
-			return &ptrV
-		},
-	}
 	poolInitializer = func(reflectType reflect.Type) FieldNewValuePool {
 		v, _ := normalPool.LoadOrStore(reflectType, &sync.Pool{
 			New: func() interface{} {

schema/relationship.go

@@ -5,8 +5,12 @@ import (
 	"fmt"
 	"reflect"
 	"strings"
+	"sync"
 
 	"github.com/jinzhu/inflection"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
+
 	"gorm.io/gorm/clause"
 )
 
@@ -27,6 +31,10 @@ type Relationships struct {
 	HasMany   []*Relationship
 	Many2Many []*Relationship
 	Relations map[string]*Relationship
+
+	EmbeddedRelations map[string]*Relationships
+
+	Mux sync.RWMutex
 }
 
 type Relationship struct {
@@ -70,12 +78,12 @@ 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 != "" {
+	if hasPolymorphicRelation(field.TagSettings) {
-		schema.buildPolymorphicRelation(relation, field, polymorphic)
+		schema.buildPolymorphicRelation(relation, field)
 	} else if many2many := field.TagSettings["MANY2MANY"]; many2many != "" {
 		schema.buildMany2ManyRelation(relation, field, many2many)
 	} else if belongsTo := field.TagSettings["BELONGSTO"]; belongsTo != "" {
@@ -87,14 +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 %s", 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 embedded 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() {
@@ -106,7 +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)
@@ -122,34 +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`
+// hasPolymorphicRelation check if has polymorphic relation
-//     type User struct {
+// 1. `POLYMORPHIC` tag
-//       Toys []Toy `gorm:"polymorphic:Owner;"`
+// 2. `POLYMORPHICTYPE` and `POLYMORPHICID` tag
-//     }
+func hasPolymorphicRelation(tagSettings map[string]string) bool {
-//     type Pet struct {
+	if _, ok := tagSettings["POLYMORPHIC"]; ok {
-//       Toy Toy `gorm:"polymorphic:Owner;"`
+		return true
-//     }
-//     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"],
 	}
 
+	_, 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 %s, missing field %s", 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 %s, missing field %s", 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 {
@@ -161,10 +237,17 @@ 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 %s", 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
 		if copyableDataType(primaryKeyField.DataType) {
 			relation.Polymorphic.PolymorphicID.DataType = primaryKeyField.DataType
@@ -191,7 +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"])
 	)
@@ -224,26 +308,24 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 	}
 
 	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 := strings.Title(relation.FieldSchema.Name) + relField.Name
+		joinFieldName := cases.Title(language.Und, cases.NoLower).String(relation.FieldSchema.Name) + relField.Name
-		if len(joinReferences) > idx {
-			joinFieldName = strings.Title(joinReferences[idx])
-		}
 
 		if _, ok := ownFieldsMap[joinFieldName]; ok {
 			if field.Name != relation.FieldSchema.Name {
@@ -253,22 +335,32 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 			}
 		}
 
-		fieldsMap[joinFieldName] = relField
+		if len(joinReferences) > idx {
-		joinTableFields = append(joinTableFields, reflect.StructField{
+			joinFieldName = cases.Title(language.Und, cases.NoLower).String(joinReferences[idx])
-			Name:    joinFieldName,
+		}
-			PkgPath: relField.StructField.PkgPath,
+
-			Type:    relField.StructField.Type,
+		referFieldsMap[joinFieldName] = relField
-			Tag:     removeSettingFromTag(relField.StructField.Tag, "column", "autoincrement", "index", "unique", "uniqueindex"),
+
-		})
+		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
@@ -315,31 +407,37 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 				f.Size = fieldsMap[f.Name].Size
 			}
 			relation.JoinTable.PrimaryFields = append(relation.JoinTable.PrimaryFields, f)
-			ownPrimaryField := schema == fieldsMap[f.Name].Schema && ownFieldsMap[f.Name]
 
-			if ownPrimaryField {
+			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: ownPrimaryField,
-			})
 		}
 	}
 }
@@ -381,7 +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 %s: define a valid foreign key for relations or 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)
 		}
 	}
 
@@ -389,34 +488,31 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 	case guessBelongs:
 		primarySchema, foreignSchema = relation.FieldSchema, schema
 	case guessEmbeddedBelongs:
-		if field.OwnerSchema != nil {
+		if field.OwnerSchema == nil {
-			primarySchema, foreignSchema = relation.FieldSchema, field.OwnerSchema
-		} else {
 			reguessOrErr()
 			return
 		}
+		primarySchema, foreignSchema = relation.FieldSchema, field.OwnerSchema
 	case guessHas:
 	case guessEmbeddedHas:
-		if field.OwnerSchema != nil {
+		if field.OwnerSchema == nil {
-			primarySchema, foreignSchema = field.OwnerSchema, relation.FieldSchema
-		} else {
 			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 {
+			f := foreignSchema.LookUpField(foreignKey)
-				foreignFields = append(foreignFields, f)
+			if f == nil {
-			} else {
 				reguessOrErr()
 				return
 			}
+			foreignFields = append(foreignFields, f)
 		}
 	} else {
-		var primaryFields []*Field
+		primarySchemaName := primarySchema.Name
-		var primarySchemaName = primarySchema.Name
 		if primarySchemaName == "" {
 			primarySchemaName = relation.FieldSchema.Name
 		}
@@ -431,6 +527,7 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 			primaryFields = primarySchema.PrimaryFields
 		}
 
+	primaryFieldLoop:
 		for _, primaryField := range primaryFields {
 			lookUpName := primarySchemaName + primaryField.Name
 			if gl == guessBelongs {
@@ -439,23 +536,33 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 
 			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 {
@@ -469,7 +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) {
@@ -505,6 +612,7 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 	}
 }
 
+// Constraint is ForeignKey Constraint
 type Constraint struct {
 	Name            string
 	Field           *Field
@@ -516,6 +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 == "-" {
@@ -530,6 +663,7 @@ func (rel *Relationship) ParseConstraint() *Constraint {
 					if !(rel.References[idx].PrimaryKey == ref.PrimaryKey && rel.References[idx].ForeignKey == ref.ForeignKey &&
 						rel.References[idx].PrimaryValue == ref.PrimaryValue) {
 						matched = false
+						break
 					}
 				}
 
@@ -542,7 +676,7 @@ func (rel *Relationship) ParseConstraint() *Constraint {
 
 	var (
 		name     string
-		idx      = strings.Index(str, ",")
+		idx      = strings.IndexByte(str, ',')
 		settings = ParseTagSetting(str, ",")
 	)
 
@@ -629,8 +763,9 @@ func (rel *Relationship) ToQueryConditions(ctx context.Context, reflectValue ref
 }
 
 func copyableDataType(str DataType) bool {
+	lowerStr := strings.ToLower(string(str))
 	for _, s := range []string{"auto_increment", "primary key"} {
-		if strings.Contains(strings.ToLower(string(str)), s) {
+		if strings.Contains(lowerStr, s) {
 			return false
 		}
 	}

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)
@@ -121,6 +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
@@ -305,6 +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
@@ -491,6 +541,320 @@ 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
@@ -615,7 +979,7 @@ func TestParseConstraintNameWithSchemaQualifiedLongTableName(t *testing.T) {
 	s, err := schema.Parse(
 		&Book{},
 		&sync.Map{},
-		schema.NamingStrategy{},
+		schema.NamingStrategy{IdentifierMaxLength: 64},
 	)
 	if err != nil {
 		t.Fatalf("Failed to parse schema")

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
@@ -51,9 +68,10 @@ func (schema Schema) String() string {
 }
 
 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
 }
 
@@ -67,10 +85,35 @@ 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
 }
 
+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, "")
@@ -112,7 +155,7 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 		schemaCacheKey = modelType
 	}
 
-	// Load exist schmema cache, return if exists
+	// 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
@@ -125,6 +168,9 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 	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
 	}
@@ -133,20 +179,21 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 	}
 
 	schema := &Schema{
-		Name:           modelType.Name(),
+		Name:             modelType.Name(),
-		ModelType:      modelType,
+		ModelType:        modelType,
-		Table:          tableName,
+		Table:            tableName,
-		FieldsByName:   map[string]*Field{},
+		FieldsByName:     map[string]*Field{},
-		FieldsByDBName: map[string]*Field{},
+		FieldsByBindName: map[string]*Field{},
-		Relationships:  Relationships{Relations: map[string]*Relationship{}},
+		FieldsByDBName:   map[string]*Field{},
-		cacheStore:     cacheStore,
+		Relationships:    Relationships{Relations: map[string]*Relationship{}},
-		namer:          namer,
+		cacheStore:       cacheStore,
-		initialized:    make(chan struct{}),
+		namer:            namer,
+		initialized:      make(chan struct{}),
 	}
 	// When the schema initialization is completed, the channel will be closed
 	defer close(schema.initialized)
 
-	// Load exist schmema cache, return if exists
+	// 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
@@ -169,6 +216,7 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 			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)) {
@@ -177,6 +225,7 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 				}
 				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 {
@@ -195,8 +244,11 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 		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")
@@ -214,8 +266,18 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 		}
 	}
 
-	if schema.PrioritizedPrimaryField == nil && len(schema.PrimaryFields) == 1 {
+	if schema.PrioritizedPrimaryField == nil {
-		schema.PrioritizedPrimaryField = schema.PrimaryFields[0]
+		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 {
@@ -223,7 +285,7 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 	}
 
 	for _, field := range schema.Fields {
-		if field.HasDefaultValue && field.DefaultValueInterface == nil {
+		if field.DataType != "" && field.HasDefaultValue && field.DefaultValueInterface == nil {
 			schema.FieldsWithDefaultDBValue = append(schema.FieldsWithDefaultDBValue, field)
 		}
 	}
@@ -242,14 +304,26 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 		}
 	}
 
-	callbacks := []string{"BeforeCreate", "AfterCreate", "BeforeUpdate", "AfterUpdate", "BeforeSave", "AfterSave", "BeforeDelete", "AfterDelete", "AfterFind"}
+	callbackTypes := []callbackType{
-	for _, name := range callbacks {
+		callbackTypeBeforeCreate, callbackTypeAfterCreate,
-		if methodValue := modelValue.MethodByName(name); methodValue.IsValid() {
+		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
+			case "func(*gorm.DB) error":
-				reflect.Indirect(reflect.ValueOf(schema)).FieldByName(name).SetBool(true)
+				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) error`. Please see https://gorm.io/docs/hooks.html", 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)
 			}
 		}
 	}
@@ -271,11 +345,12 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 
 	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
 				}
 			}
 
@@ -302,6 +377,39 @@ func ParseWithSpecialTableName(dest interface{}, cacheStore *sync.Map, namer Nam
 	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 {

schema/schema_helper_test.go

@@ -163,8 +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 {
+				for i := range relation.JoinTable.Fields {
-					checkSchemaField(t, r.JoinTable, &f, nil)
+					checkSchemaField(t, r.JoinTable, &relation.JoinTable.Fields[i], nil)
 				}
 			}
 
@@ -201,6 +201,37 @@ 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) {

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 {
+	for i := range fields {
-		checkSchemaField(t, user, &f, func(f *schema.Field) {
+		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 {
+	for i := range fields {
-		checkSchemaField(t, user, &f, func(f *schema.Field) {
+		checkSchemaField(t, user, &fields[i], func(f *schema.Field) {
 			f.Creatable = true
 			f.Updatable = true
 			f.Readable = true
@@ -293,3 +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

@@ -70,8 +70,7 @@ type SerializerValuerInterface interface {
 }
 
 // JSONSerializer json serializer
-type JSONSerializer struct {
+type JSONSerializer struct{}
-}
 
 // Scan implements serializer interface
 func (JSONSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
@@ -85,10 +84,15 @@ func (JSONSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value,
 		case string:
 			bytes = []byte(v)
 		default:
-			return fmt.Errorf("failed to unmarshal JSONB value: %#v", dbValue)
+			bytes, err = json.Marshal(v)
+			if err != nil {
+				return err
+			}
 		}
 
-		err = json.Unmarshal(bytes, fieldValue.Interface())
+		if len(bytes) > 0 {
+			err = json.Unmarshal(bytes, fieldValue.Interface())
+		}
 	}
 
 	field.ReflectValueOf(ctx, dst).Set(fieldValue.Elem())
@@ -98,18 +102,23 @@ func (JSONSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value,
 // 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 {
+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 {
+	if err = t.Scan(dbValue); err == nil && t.Valid {
-		err = field.Set(ctx, dst, t.Time)
+		err = field.Set(ctx, dst, t.Time.Unix())
 	}
 
 	return
@@ -117,9 +126,15 @@ func (UnixSecondSerializer) Scan(ctx context.Context, field *Field, dst reflect.
 
 // 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.ValueOf(v).Int(), 0)
+		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)
 	}
@@ -127,8 +142,7 @@ func (UnixSecondSerializer) Value(ctx context.Context, field *Field, dst reflect
 }
 
 // GobSerializer gob serializer
-type GobSerializer struct {
+type GobSerializer struct{}
-}
 
 // Scan implements serializer interface
 func (GobSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
@@ -142,8 +156,10 @@ func (GobSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value,
 		default:
 			return fmt.Errorf("failed to unmarshal gob value: %#v", dbValue)
 		}
-		decoder := gob.NewDecoder(bytes.NewBuffer(bytesValue))
+		if len(bytesValue) > 0 {
-		err = decoder.Decode(fieldValue.Interface())
+			decoder := gob.NewDecoder(bytes.NewBuffer(bytesValue))
+			err = decoder.Decode(fieldValue.Interface())
+		}
 	}
 	field.ReflectValueOf(ctx, dst).Set(fieldValue.Elem())
 	return

schema/utils.go

@@ -2,6 +2,7 @@ package schema
 
 import (
 	"context"
+	"fmt"
 	"reflect"
 	"regexp"
 	"strings"
@@ -59,10 +60,18 @@ 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(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(ctx, value); !isZero {
@@ -106,6 +115,11 @@ func GetIdentityFieldValuesMap(ctx context.Context, reflectValue reflect.Value,
 		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))}
@@ -124,7 +138,7 @@ func GetIdentityFieldValuesMap(ctx context.Context, reflectValue reflect.Value,
 		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()
 			}
 

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 {
@@ -78,18 +89,19 @@ 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}}
+	return []clause.Interface{SoftDeleteUpdateClause{Field: f, ZeroValue: parseZeroValueTag(f)}}
 }
 
 type SoftDeleteUpdateClause struct {
-	Field *schema.Field
+	ZeroValue sql.NullString
+	Field     *schema.Field
 }
 
 func (sd SoftDeleteUpdateClause) Name() string {
@@ -109,11 +121,12 @@ func (sd SoftDeleteUpdateClause) ModifyStatement(stmt *Statement) {
 }
 
 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 {

statement.go

@@ -30,8 +30,9 @@ type Statement struct {
 	Clauses              map[string]clause.Clause
 	BuildClauses         []string
 	Distinct             bool
-	Selects              []string // selected columns
+	Selects              []string          // selected columns
-	Omits                []string // omit columns
+	Omits                []string          // omit columns
+	ColumnMapping        map[string]string // map columns
 	Joins                []join
 	Preloads             map[string][]interface{}
 	Settings             sync.Map
@@ -46,12 +47,18 @@ type Statement struct {
 	attrs                []interface{}
 	assigns              []interface{}
 	scopes               []func(*DB) *DB
+	Result               *result
 }
 
 type join struct {
-	Name  string
+	Name       string
-	Conds []interface{}
+	Alias      string
-	On    *clause.Where
+	Conds      []interface{}
+	On         *clause.Where
+	Selects    []string
+	Omits      []string
+	Expression clause.Expression
+	JoinType   clause.JoinType
 }
 
 // StatementModifier statement modifier interface
@@ -117,6 +124,8 @@ func (stmt *Statement) QuoteTo(writer clause.Writer, field interface{}) {
 				write(v.Raw, stmt.Schema.PrioritizedPrimaryField.DBName)
 			} else if len(stmt.Schema.DBNames) > 0 {
 				write(v.Raw, stmt.Schema.DBNames[0])
+			} else {
+				stmt.DB.AddError(ErrModelAccessibleFieldsRequired) //nolint:typecheck,errcheck
 			}
 		} else {
 			write(v.Raw, v.Name)
@@ -179,6 +188,10 @@ func (stmt *Statement) AddVar(writer clause.Writer, vars ...interface{}) {
 			} 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:
@@ -195,19 +208,21 @@ func (stmt *Statement) AddVar(writer clause.Writer, vars ...interface{}) {
 			} else {
 				writer.WriteString("(NULL)")
 			}
-		case *DB:
+		case interface{ getInstance() *DB }:
-			subdb := v.Session(&Session{Logger: logger.Discard, DryRun: true}).getInstance()
+			cv := v.getInstance()
-			if v.Statement.SQL.Len() > 0 {
+
+			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)
 				}
 
@@ -304,19 +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...))
@@ -336,7 +363,11 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 			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{}:
 			keys := make([]string, 0, len(v))
@@ -347,12 +378,16 @@ 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 {
 						// optimize reflect value length
 						valueLen := reflectValue.Len()
@@ -361,10 +396,10 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 							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:
@@ -391,9 +426,9 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 						if selected || (!restricted && field.Readable) {
 							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})
 								}
 							}
 						}
@@ -405,9 +440,9 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...interface{}) []
 							if selected || (!restricted && field.Readable) {
 								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})
 									}
 								}
 							}
@@ -432,18 +467,22 @@ func (stmt *Statement) BuildCondition(query interface{}, args ...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
@@ -495,12 +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 {
@@ -536,8 +577,9 @@ func (stmt *Statement) clone() *Statement {
 }
 
 // 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
@@ -605,10 +647,10 @@ func (stmt *Statement) Changed(fields ...string) bool {
 	changed := func(field *schema.Field) bool {
 		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 mv, mok := stmt.Dest.(map[string]interface{}); mok {
-				if fv, ok := v[field.Name]; ok {
+				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 {
@@ -618,6 +660,9 @@ func (stmt *Statement) Changed(fields ...string) bool {
 				}
 
 				changedValue, zero := field.ValueOf(stmt.Context, destValue)
+				if v {
+					return !utils.AssertEqual(changedValue, fieldValue)
+				}
 				return !zero && !utils.AssertEqual(changedValue, fieldValue)
 			}
 		}
@@ -643,54 +688,62 @@ func (stmt *Statement) Changed(fields ...string) bool {
 	return false
 }
 
-var nameMatcher = regexp.MustCompile(`^[\W]?(?:[a-z_]+?)[\W]?\.[\W]?([a-z_]+?)[\W]?$`)
+var matchName = func() func(tableColumn string) (table, column string) {
+	nameMatcher := regexp.MustCompile(`^(?:\W?(\w+?)\W?\.)?(?:(\*)|\W?(\w+?)\W?)$`)
+	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
+	processColumn := func(column string, result bool) {
-	for _, column := range stmt.Selects {
 		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 matches := nameMatcher.FindStringSubmatch(column); len(matches) == 2 {
+		} else if table, col := matchName(column); col != "" && (table == stmt.Table || table == "") {
-			results[matches[1]] = true
+			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 {
+	for _, column := range stmt.Omits {
-		if stmt.Schema == nil {
+		processColumn(column, false)
-			results[omit] = false
-		} else if omit == "*" {
-			for _, dbName := range stmt.Schema.DBNames {
-				results[dbName] = 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 if matches := nameMatcher.FindStringSubmatch(omit); len(matches) == 2 {
-			results[matches[1]] = false
-		} else {
-			results[omit] = false
-		}
 	}
 
 	if stmt.Schema != nil {

statement_test.go

@@ -35,15 +35,36 @@ 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{
+	for k, v := range map[string][]string{
-		"table.name":     "name",
+		"table.name":         {"table", "name"},
-		"`table`.`name`": "name",
+		"`table`.`name`":     {"table", "name"},
-		"'table'.'name'": "name",
+		"'table'.'name'":     {"table", "name"},
-		"'table'.name":   "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 matches := nameMatcher.FindStringSubmatch(k); len(matches) < 2 || matches[1] != v {
+		if table, column := matchName(k); table != v[0] || column != v[1] {
-			t.Errorf("failed to match value: %v, got %v, expect: %v", k, matches, v)
+			t.Errorf("failed to match value: %v, got %v, expect: %v", k, []string{table, column}, v)
 		}
 	}
 }

tests/associations_belongs_to_test.go

@@ -3,6 +3,7 @@ package tests_test
 import (
 	"testing"
 
+	"gorm.io/gorm"
 	. "gorm.io/gorm/utils/tests"
 )
 
@@ -137,6 +138,7 @@ func TestBelongsToAssociation(t *testing.T) {
 	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")
 	}
 }
@@ -224,3 +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))
+	}
+}

tests/associations_has_many_test.go

@@ -3,6 +3,7 @@ package tests_test
 import (
 	"testing"
 
+	"gorm.io/gorm"
 	. "gorm.io/gorm/utils/tests"
 )
 
@@ -421,7 +422,7 @@ func TestPolymorphicHasManyAssociation(t *testing.T) {
 func TestPolymorphicHasManyAssociationForSlice(t *testing.T) {
 	users := []User{
 		*GetUser("slice-hasmany-1", Config{Toys: 2}),
-		*GetUser("slice-hasmany-2", Config{Toys: 0}),
+		*GetUser("slice-hasmany-2", Config{Toys: 0, Tools: 2}),
 		*GetUser("slice-hasmany-3", Config{Toys: 4}),
 	}
 
@@ -429,6 +430,7 @@ func TestPolymorphicHasManyAssociationForSlice(t *testing.T) {
 
 	// Count
 	AssertAssociationCount(t, users, "Toys", 6, "")
+	AssertAssociationCount(t, users, "Tools", 2, "")
 
 	// Find
 	var toys []Toy
@@ -436,6 +438,14 @@ func TestPolymorphicHasManyAssociationForSlice(t *testing.T) {
 		t.Errorf("toys count should be %v, but got %v", 6, len(toys))
 	}
 
+	// Find Tools (polymorphic with custom type and id)
+	var tools []Tools
+	DB.Model(&users).Association("Tools").Find(&tools)
+
+	if len(tools) != 2 {
+		t.Errorf("tools count should be %v, but got %v", 2, len(tools))
+	}
+
 	// Append
 	DB.Model(&users).Association("Toys").Append(
 		&Toy{Name: "toy-slice-append-1"},
@@ -471,3 +481,88 @@ func TestPolymorphicHasManyAssociationForSlice(t *testing.T) {
 	DB.Model(&users).Association("Toys").Clear()
 	AssertAssociationCount(t, users, "Toys", 0, "After Clear")
 }
+
+func TestHasManyAssociationUnscoped(t *testing.T) {
+	type ItemContent struct {
+		gorm.Model
+		ItemID       uint   `gorm:"not null"`
+		Name         string `gorm:"not null;type:varchar(50)"`
+		LanguageCode string `gorm:"not null;type:varchar(2)"`
+	}
+	type Item struct {
+		gorm.Model
+		Logo     string        `gorm:"not null;type:varchar(50)"`
+		Contents []ItemContent `gorm:"foreignKey:ItemID"`
+	}
+
+	tx := DB.Session(&gorm.Session{})
+	tx.Migrator().DropTable(&ItemContent{}, &Item{})
+	tx.AutoMigrate(&ItemContent{}, &Item{})
+
+	item := Item{
+		Logo: "logo",
+		Contents: []ItemContent{
+			{Name: "name", LanguageCode: "en"},
+			{Name: "ar name", LanguageCode: "ar"},
+		},
+	}
+	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("Contents").Unscoped().Replace([]ItemContent{
+		{Name: "updated name", LanguageCode: "en"},
+		{Name: "ar updated name", LanguageCode: "ar"},
+		{Name: "le nom", LanguageCode: "fr"},
+	}); err != nil {
+		t.Errorf("failed to replace item content, got error: %v", err)
+	}
+
+	if count := tx.Model(&item).Association("Contents").Count(); count != 3 {
+		t.Errorf("expected %d contents, got %d", 3, count)
+	}
+
+	var contents []ItemContent
+	if err := tx.Find(&contents).Error; err != nil {
+		t.Errorf("failed to find contents, got error: %v", err)
+	}
+	if len(contents) != 3 {
+		t.Errorf("expected %d contents, got %d", 3, len(contents))
+	}
+
+	// test delete
+	if err := tx.Model(&item).Association("Contents").Unscoped().Delete(&contents[0]); err != nil {
+		t.Errorf("failed to delete Contents, got error: %v", err)
+	}
+	if count := tx.Model(&item).Association("Contents").Count(); count != 2 {
+		t.Errorf("expected %d contents, got %d", 2, count)
+	}
+
+	// test clear
+	if err := tx.Model(&item).Association("Contents").Unscoped().Clear(); err != nil {
+		t.Errorf("failed to clear contents association, got error: %v", err)
+	}
+	if count := tx.Model(&item).Association("Contents").Count(); count != 0 {
+		t.Errorf("expected %d contents, got %d", 0, count)
+	}
+
+	if err := tx.Find(&contents).Error; err != nil {
+		t.Errorf("failed to find contents, got error: %v", err)
+	}
+	if len(contents) != 0 {
+		t.Errorf("expected %d contents, got %d", 0, len(contents))
+	}
+}
+
+func TestHasManyAssociationReplaceWithNonValidValue(t *testing.T) {
+	user := User{Name: "jinzhu", Languages: []Language{{Name: "EN"}}}
+
+	if err := DB.Create(&user).Error; err != nil {
+		t.Fatalf("errors happened when create: %v", err)
+	}
+
+	if err := DB.Model(&user).Association("Languages").Replace(Language{Name: "DE"}, Language{Name: "FR"}); err == nil {
+		t.Error("expected association error to be not nil")
+	}
+}

tests/associations_has_one_test.go

@@ -255,3 +255,15 @@ func TestPolymorphicHasOneAssociationForSlice(t *testing.T) {
 	DB.Model(&pets).Association("Toy").Clear()
 	AssertAssociationCount(t, pets, "Toy", 0, "After Clear")
 }
+
+func TestHasOneAssociationReplaceWithNonValidValue(t *testing.T) {
+	user := User{Name: "jinzhu", Account: Account{Number: "1"}}
+
+	if err := DB.Create(&user).Error; err != nil {
+		t.Fatalf("errors happened when create: %v", err)
+	}
+
+	if err := DB.Model(&user).Association("Languages").Replace(Account{Number: "2"}); err == nil {
+		t.Error("expected association error to be not nil")
+	}
+}

tests/associations_many2many_test.go

@@ -1,8 +1,12 @@
 package tests_test
 
 import (
+	"fmt"
+	"sync"
 	"testing"
 
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
 	. "gorm.io/gorm/utils/tests"
 )
 
@@ -94,6 +98,8 @@ func TestMany2ManyAssociation(t *testing.T) {
 }
 
 func TestMany2ManyOmitAssociations(t *testing.T) {
+	tidbSkip(t, "not support the foreign key feature")
+
 	user := *GetUser("many2many_omit_associations", Config{Languages: 2})
 
 	if err := DB.Omit("Languages.*").Create(&user).Error; err == nil {
@@ -324,3 +330,96 @@ func TestSingleTableMany2ManyAssociationForSlice(t *testing.T) {
 	DB.Model(&users).Association("Team").Clear()
 	AssertAssociationCount(t, users, "Team", 0, "After Clear")
 }
+
+func TestDuplicateMany2ManyAssociation(t *testing.T) {
+	user1 := User{Name: "TestDuplicateMany2ManyAssociation-1", Languages: []Language{
+		{Code: "TestDuplicateMany2ManyAssociation-language-1"},
+		{Code: "TestDuplicateMany2ManyAssociation-language-2"},
+	}}
+
+	user2 := User{Name: "TestDuplicateMany2ManyAssociation-1", Languages: []Language{
+		{Code: "TestDuplicateMany2ManyAssociation-language-1"},
+		{Code: "TestDuplicateMany2ManyAssociation-language-3"},
+	}}
+	users := []*User{&user1, &user2}
+	var err error
+	err = DB.Session(&gorm.Session{FullSaveAssociations: true}).Save(users).Error
+	AssertEqual(t, nil, err)
+
+	var findUser1 User
+	err = DB.Preload("Languages").Where("id = ?", user1.ID).First(&findUser1).Error
+	AssertEqual(t, nil, err)
+	AssertEqual(t, user1, findUser1)
+
+	var findUser2 User
+	err = DB.Preload("Languages").Where("id = ?", user2.ID).First(&findUser2).Error
+	AssertEqual(t, nil, err)
+	AssertEqual(t, user2, findUser2)
+}
+
+func TestConcurrentMany2ManyAssociation(t *testing.T) {
+	db, err := OpenTestConnection(&gorm.Config{})
+	if err != nil {
+		t.Fatalf("open test connection failed, err: %+v", err)
+	}
+
+	count := 3
+
+	var languages []Language
+	for i := 0; i < count; i++ {
+		language := Language{Code: fmt.Sprintf("consurrent %d", i)}
+		db.Create(&language)
+		languages = append(languages, language)
+	}
+
+	user := User{}
+	db.Create(&user)
+	db.Preload("Languages").FirstOrCreate(&user)
+
+	var wg sync.WaitGroup
+	for i := 0; i < count; i++ {
+		wg.Add(1)
+		go func(user User, language Language) {
+			err := db.Model(&user).Association("Languages").Append(&language)
+			AssertEqual(t, err, nil)
+
+			wg.Done()
+		}(user, languages[i])
+	}
+	wg.Wait()
+
+	var find User
+	err = db.Preload(clause.Associations).Where("id = ?", user.ID).First(&find).Error
+	AssertEqual(t, err, nil)
+	AssertAssociationCount(t, find, "Languages", int64(count), "after concurrent append")
+}
+
+func TestMany2ManyDuplicateBelongsToAssociation(t *testing.T) {
+	user1 := User{Name: "TestMany2ManyDuplicateBelongsToAssociation-1", Friends: []*User{
+		{Name: "TestMany2ManyDuplicateBelongsToAssociation-friend-1", Company: Company{
+			ID:   1,
+			Name: "Test-company-1",
+		}},
+	}}
+
+	user2 := User{Name: "TestMany2ManyDuplicateBelongsToAssociation-2", Friends: []*User{
+		{Name: "TestMany2ManyDuplicateBelongsToAssociation-friend-2", Company: Company{
+			ID:   1,
+			Name: "Test-company-1",
+		}},
+	}}
+	users := []*User{&user1, &user2}
+	var err error
+	err = DB.Session(&gorm.Session{FullSaveAssociations: true}).Save(users).Error
+	AssertEqual(t, nil, err)
+
+	var findUser1 User
+	err = DB.Preload("Friends.Company").Where("id = ?", user1.ID).First(&findUser1).Error
+	AssertEqual(t, nil, err)
+	AssertEqual(t, user1, findUser1)
+
+	var findUser2 User
+	err = DB.Preload("Friends.Company").Where("id = ?", user2.ID).First(&findUser2).Error
+	AssertEqual(t, nil, err)
+	AssertEqual(t, user2, findUser2)
+}

tests/associations_test.go

@@ -4,6 +4,8 @@ import (
 	"testing"
 
 	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+	"gorm.io/gorm/schema"
 	. "gorm.io/gorm/utils/tests"
 )
 
@@ -69,6 +71,8 @@ func TestAssociationNotNullClear(t *testing.T) {
 }
 
 func TestForeignKeyConstraints(t *testing.T) {
+	tidbSkip(t, "not support the foreign key feature")
+
 	type Profile struct {
 		ID       uint
 		Name     string
@@ -124,6 +128,8 @@ func TestForeignKeyConstraints(t *testing.T) {
 }
 
 func TestForeignKeyConstraintsBelongsTo(t *testing.T) {
+	tidbSkip(t, "not support the foreign key feature")
+
 	type Profile struct {
 		ID    uint
 		Name  string
@@ -284,3 +290,107 @@ func TestAssociationError(t *testing.T) {
 	err = DB.Model(&emptyUser).Association("Languages").Delete(&user1.Languages)
 	AssertEqual(t, err, gorm.ErrPrimaryKeyRequired)
 }
+
+type (
+	myType           string
+	emptyQueryClause struct {
+		Field *schema.Field
+	}
+)
+
+func (myType) QueryClauses(f *schema.Field) []clause.Interface {
+	return []clause.Interface{emptyQueryClause{Field: f}}
+}
+
+func (sd emptyQueryClause) Name() string {
+	return "empty"
+}
+
+func (sd emptyQueryClause) Build(clause.Builder) {
+}
+
+func (sd emptyQueryClause) MergeClause(*clause.Clause) {
+}
+
+func (sd emptyQueryClause) ModifyStatement(stmt *gorm.Statement) {
+	// do nothing
+}
+
+func TestAssociationEmptyQueryClause(t *testing.T) {
+	type Organization struct {
+		gorm.Model
+		Name string
+	}
+	type Region struct {
+		gorm.Model
+		Name          string
+		Organizations []Organization `gorm:"many2many:region_orgs;"`
+	}
+	type RegionOrg struct {
+		RegionId       uint
+		OrganizationId uint
+		Empty          myType
+	}
+	if err := DB.SetupJoinTable(&Region{}, "Organizations", &RegionOrg{}); err != nil {
+		t.Fatalf("Failed to set up join table, got error: %s", err)
+	}
+	if err := DB.Migrator().DropTable(&Organization{}, &Region{}); err != nil {
+		t.Fatalf("Failed to migrate, got error: %s", err)
+	}
+	if err := DB.AutoMigrate(&Organization{}, &Region{}); err != nil {
+		t.Fatalf("Failed to migrate, got error: %v", err)
+	}
+	region := &Region{Name: "Region1"}
+	if err := DB.Create(region).Error; err != nil {
+		t.Fatalf("fail to create region %v", err)
+	}
+	var orgs []Organization
+
+	if err := DB.Model(&Region{}).Association("Organizations").Find(&orgs); err != nil {
+		t.Fatalf("fail to find region organizations %v", err)
+	} else {
+		AssertEqual(t, len(orgs), 0)
+	}
+}
+
+type AssociationEmptyUser struct {
+	ID   uint
+	Name string
+	Pets []AssociationEmptyPet
+}
+
+type AssociationEmptyPet struct {
+	AssociationEmptyUserID *uint  `gorm:"uniqueIndex:uniq_user_id_name"`
+	Name                   string `gorm:"uniqueIndex:uniq_user_id_name;size:256"`
+}
+
+func TestAssociationEmptyPrimaryKey(t *testing.T) {
+	if DB.Dialector.Name() != "mysql" {
+		t.Skip()
+	}
+	DB.Migrator().DropTable(&AssociationEmptyUser{}, &AssociationEmptyPet{})
+	DB.AutoMigrate(&AssociationEmptyUser{}, &AssociationEmptyPet{})
+
+	id := uint(100)
+	user := AssociationEmptyUser{
+		ID:   id,
+		Name: "jinzhu",
+		Pets: []AssociationEmptyPet{
+			{AssociationEmptyUserID: &id, Name: "bar"},
+			{AssociationEmptyUserID: &id, Name: "foo"},
+		},
+	}
+
+	err := DB.Session(&gorm.Session{FullSaveAssociations: true}).Create(&user).Error
+	if err != nil {
+		t.Fatalf("Failed to create, got error: %v", err)
+	}
+
+	var result AssociationEmptyUser
+	err = DB.Preload("Pets").First(&result, &id).Error
+	if err != nil {
+		t.Fatalf("Failed to find, got error: %v", err)
+	}
+
+	AssertEqual(t, result, user)
+}

tests/benchmark_test.go

@@ -1,6 +1,7 @@
 package tests_test
 
 import (
+	"fmt"
 	"testing"
 
 	. "gorm.io/gorm/utils/tests"
@@ -24,6 +25,45 @@ func BenchmarkFind(b *testing.B) {
 	}
 }
 
+func BenchmarkScan(b *testing.B) {
+	user := *GetUser("scan", Config{})
+	DB.Create(&user)
+
+	var u User
+	b.ResetTimer()
+	for x := 0; x < b.N; x++ {
+		DB.Raw("select * from users where id = ?", user.ID).Scan(&u)
+	}
+}
+
+func BenchmarkScanSlice(b *testing.B) {
+	DB.Exec("delete from users")
+	for i := 0; i < 10_000; i++ {
+		user := *GetUser(fmt.Sprintf("scan-%d", i), Config{})
+		DB.Create(&user)
+	}
+
+	var u []User
+	b.ResetTimer()
+	for x := 0; x < b.N; x++ {
+		DB.Raw("select * from users").Scan(&u)
+	}
+}
+
+func BenchmarkScanSlicePointer(b *testing.B) {
+	DB.Exec("delete from users")
+	for i := 0; i < 10_000; i++ {
+		user := *GetUser(fmt.Sprintf("scan-%d", i), Config{})
+		DB.Create(&user)
+	}
+
+	var u []*User
+	b.ResetTimer()
+	for x := 0; x < b.N; x++ {
+		DB.Raw("select * from users").Scan(&u)
+	}
+}
+
 func BenchmarkUpdate(b *testing.B) {
 	user := *GetUser("find", Config{})
 	DB.Create(&user)

tests/callbacks_test.go

@@ -38,6 +38,7 @@ func c2(*gorm.DB) {}
 func c3(*gorm.DB) {}
 func c4(*gorm.DB) {}
 func c5(*gorm.DB) {}
+func c6(*gorm.DB) {}
 
 func TestCallbacks(t *testing.T) {
 	type callback struct {
@@ -90,7 +91,7 @@ func TestCallbacks(t *testing.T) {
 		},
 		{
 			callbacks: []callback{{h: c1}, {h: c2, before: "c4", after: "c5"}, {h: c3}, {h: c4}, {h: c5}, {h: c2, remove: true}},
-			results:   []string{"c1", "c5", "c3", "c4"},
+			results:   []string{"c1", "c3", "c4", "c5"},
 		},
 		{
 			callbacks: []callback{{h: c1}, {name: "c", h: c2}, {h: c3}, {name: "c", h: c4, replace: true}},
@@ -112,6 +113,9 @@ func TestCallbacks(t *testing.T) {
 
 	for idx, data := range datas {
 		db, err := gorm.Open(nil, nil)
+		if err != nil {
+			t.Fatal(err)
+		}
 		callbacks := db.Callback()
 
 		for _, c := range data.callbacks {
@@ -168,3 +172,83 @@ func TestCallbacks(t *testing.T) {
 		}
 	}
 }
+
+func TestPluginCallbacks(t *testing.T) {
+	db, _ := gorm.Open(nil, nil)
+	createCallback := db.Callback().Create()
+
+	createCallback.Before("*").Register("plugin_1_fn1", c1)
+	createCallback.After("*").Register("plugin_1_fn2", c2)
+
+	if ok, msg := assertCallbacks(createCallback, []string{"c1", "c2"}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+
+	// plugin 2
+	createCallback.Before("*").Register("plugin_2_fn1", c3)
+	if ok, msg := assertCallbacks(createCallback, []string{"c3", "c1", "c2"}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+
+	createCallback.After("*").Register("plugin_2_fn2", c4)
+	if ok, msg := assertCallbacks(createCallback, []string{"c3", "c1", "c2", "c4"}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+
+	// plugin 3
+	createCallback.Before("*").Register("plugin_3_fn1", c5)
+	if ok, msg := assertCallbacks(createCallback, []string{"c5", "c3", "c1", "c2", "c4"}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+
+	createCallback.After("*").Register("plugin_3_fn2", c6)
+	if ok, msg := assertCallbacks(createCallback, []string{"c5", "c3", "c1", "c2", "c4", "c6"}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+}
+
+func TestCallbacksGet(t *testing.T) {
+	db, _ := gorm.Open(nil, nil)
+	createCallback := db.Callback().Create()
+
+	createCallback.Before("*").Register("c1", c1)
+	if cb := createCallback.Get("c1"); reflect.DeepEqual(cb, c1) {
+		t.Errorf("callbacks tests failed, got: %p, want: %p", cb, c1)
+	}
+
+	createCallback.Remove("c1")
+	if cb := createCallback.Get("c2"); cb != nil {
+		t.Errorf("callbacks test failed. got: %p, want: nil", cb)
+	}
+}
+
+func TestCallbacksRemove(t *testing.T) {
+	db, _ := gorm.Open(nil, nil)
+	createCallback := db.Callback().Create()
+
+	createCallback.Before("*").Register("c1", c1)
+	createCallback.After("*").Register("c2", c2)
+	createCallback.Before("c4").Register("c3", c3)
+	createCallback.After("c2").Register("c4", c4)
+
+	// callbacks: []string{"c1", "c3", "c4", "c2"}
+	createCallback.Remove("c1")
+	if ok, msg := assertCallbacks(createCallback, []string{"c3", "c4", "c2"}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+
+	createCallback.Remove("c4")
+	if ok, msg := assertCallbacks(createCallback, []string{"c3", "c2"}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+
+	createCallback.Remove("c2")
+	if ok, msg := assertCallbacks(createCallback, []string{"c3"}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+
+	createCallback.Remove("c3")
+	if ok, msg := assertCallbacks(createCallback, []string{}); !ok {
+		t.Errorf("callbacks tests failed, got %v", msg)
+	}
+}

tests/check_subset_model_change_test.go

@@ -0,0 +1,88 @@
+package tests_test
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"gorm.io/gorm"
+)
+
+type Man struct {
+	ID     int
+	Age    int
+	Name   string
+	Detail string
+}
+
+// Panic-safe BeforeUpdate hook that checks for Changed("age")
+func (m *Man) BeforeUpdate(tx *gorm.DB) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("panic in BeforeUpdate: %v", r)
+		}
+	}()
+
+	if !tx.Statement.Changed("age") {
+		return nil
+	}
+	return nil
+}
+
+func (m *Man) update(data interface{}) error {
+	return DB.Set("data", data).Model(m).Where("id = ?", m.ID).Updates(data).Error
+}
+
+func TestBeforeUpdateStatementChanged(t *testing.T) {
+	DB.AutoMigrate(&Man{})
+	type TestCase struct {
+		BaseObjects Man
+		change      interface{}
+		expectError bool
+	}
+
+	testCases := []TestCase{
+		{
+			BaseObjects: Man{ID: 1, Age: 18, Name: "random-name"},
+			change: struct {
+				Age int
+			}{Age: 20},
+			expectError: false,
+		},
+		{
+			BaseObjects: Man{ID: 2, Age: 18, Name: "random-name"},
+			change: struct {
+				Name string
+			}{Name: "name-only"},
+			expectError: true,
+		},
+		{
+			BaseObjects: Man{ID: 2, Age: 18, Name: "random-name"},
+			change: struct {
+				Name string
+				Age int
+			}{Name: "name-only", Age: 20},
+			expectError: false,
+		},
+	}
+
+	for _, test := range testCases {
+		DB.Create(&test.BaseObjects)
+
+		// below comment is stored for future reference
+		// err := DB.Set("data", test.change).Model(&test.BaseObjects).Where("id = ?", test.BaseObjects.ID).Updates(test.change).Error
+		err := test.BaseObjects.update(test.change)
+		if strings.Contains(fmt.Sprint(err), "panic in BeforeUpdate") {
+			if !test.expectError {
+				t.Errorf("unexpected panic in BeforeUpdate for input: %+v\nerror: %v", test.change, err)
+			}
+		} else {
+			if test.expectError {
+				t.Errorf("expected panic did not occur for input: %+v", test.change)
+			}
+			if err != nil {
+				t.Errorf("unexpected GORM error: %v", err)
+			}
+		}
+	}
+}

tests/compose.yml

@@ -1,10 +1,8 @@
-version: '3'
-
 services:
   mysql:
-    image: 'mysql/mysql-server:latest'
+    image: 'mysql:latest'
     ports:
-      - 9910:3306
+      - "127.0.0.1:9910:3306"
     environment:
       - MYSQL_DATABASE=gorm
       - MYSQL_USER=gorm
@@ -13,19 +11,22 @@ services:
   postgres:
     image: 'postgres:latest'
     ports:
-      - 9920:5432
+      - "127.0.0.1:9920:5432"
     environment:
       - TZ=Asia/Shanghai
       - POSTGRES_DB=gorm
       - POSTGRES_USER=gorm
       - POSTGRES_PASSWORD=gorm
   mssql:
-    image: '${MSSQL_IMAGE:-mcmoe/mssqldocker}:latest'
+    image: '${MSSQL_IMAGE}:latest'
     ports:
-      - 9930:1433
+      - "127.0.0.1:9930:1433"
     environment:
+      - TZ=Asia/Shanghai
       - ACCEPT_EULA=Y
-      - SA_PASSWORD=LoremIpsum86
+      - MSSQL_SA_PASSWORD=LoremIpsum86
-      - MSSQL_DB=gorm
+  tidb:
-      - MSSQL_USER=gorm
+    image: 'pingcap/tidb:v6.5.0'
-      - MSSQL_PASSWORD=LoremIpsum86
+    ports:
+      - "127.0.0.1:9940:4000"
+    command: /tidb-server -store unistore -path "" -lease 0s > tidb.log 2>&1 &

tests/connpool_test.go

@@ -48,9 +48,11 @@ func (c *wrapperConnPool) Ping() error {
 }
 
 // If you use BeginTx returned *sql.Tx as shown below then you can't record queries in a transaction.
-// func (c *wrapperConnPool) BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error) {
+//
-//	 return c.db.BeginTx(ctx, opts)
+//	func (c *wrapperConnPool) BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error) {
-// }
+//		 return c.db.BeginTx(ctx, opts)
+//	}
+//
 // You should use BeginTx returned gorm.Tx which could wrap *sql.Tx then you can record all queries.
 func (c *wrapperConnPool) BeginTx(ctx context.Context, opts *sql.TxOptions) (gorm.ConnPool, error) {
 	tx, err := c.db.BeginTx(ctx, opts)
@@ -100,13 +102,13 @@ func TestConnPoolWrapper(t *testing.T) {
 		expect: []string{
 			"SELECT VERSION()",
 			"INSERT INTO `users` (`created_at`,`updated_at`,`deleted_at`,`name`,`age`,`birthday`,`company_id`,`manager_id`,`active`) VALUES (?,?,?,?,?,?,?,?,?)",
-			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT 1",
+			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT ?",
 			"INSERT INTO `users` (`created_at`,`updated_at`,`deleted_at`,`name`,`age`,`birthday`,`company_id`,`manager_id`,`active`) VALUES (?,?,?,?,?,?,?,?,?)",
-			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT 1",
+			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT ?",
-			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT 1",
+			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT ?",
 			"INSERT INTO `users` (`created_at`,`updated_at`,`deleted_at`,`name`,`age`,`birthday`,`company_id`,`manager_id`,`active`) VALUES (?,?,?,?,?,?,?,?,?)",
-			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT 1",
+			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT ?",
-			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT 1",
+			"SELECT * FROM `users` WHERE name = ? AND `users`.`deleted_at` IS NULL ORDER BY `users`.`id` LIMIT ?",
 		},
 	}
 
@@ -116,7 +118,8 @@ func TestConnPoolWrapper(t *testing.T) {
 		}
 	}()
 
-	db, err := gorm.Open(mysql.New(mysql.Config{Conn: conn}))
+	db, err := gorm.Open(mysql.New(mysql.Config{Conn: conn, DisableWithReturning: true}))
+	db.Logger = DB.Logger
 	if err != nil {
 		t.Fatalf("Should open db success, but got %v", err)
 	}

tests/count_test.go

@@ -11,6 +11,32 @@ import (
 	. "gorm.io/gorm/utils/tests"
 )
 
+func TestCountWithGroup(t *testing.T) {
+	DB.Create([]Company{
+		{Name: "company_count_group_a"},
+		{Name: "company_count_group_a"},
+		{Name: "company_count_group_a"},
+		{Name: "company_count_group_b"},
+		{Name: "company_count_group_c"},
+	})
+
+	var count1 int64
+	if err := DB.Model(&Company{}).Where("name = ?", "company_count_group_a").Group("name").Count(&count1).Error; err != nil {
+		t.Errorf(fmt.Sprintf("Count should work, but got err %v", err))
+	}
+	if count1 != 1 {
+		t.Errorf("Count with group should be 1, but got count: %v", count1)
+	}
+
+	var count2 int64
+	if err := DB.Model(&Company{}).Where("name in ?", []string{"company_count_group_b", "company_count_group_c"}).Group("name").Count(&count2).Error; err != nil {
+		t.Errorf(fmt.Sprintf("Count should work, but got err %v", err))
+	}
+	if count2 != 2 {
+		t.Errorf("Count with group should be 2, but got count: %v", count2)
+	}
+}
+
 func TestCount(t *testing.T) {
 	var (
 		user1                 = *GetUser("count-1", Config{})
@@ -142,7 +168,7 @@ func TestCount(t *testing.T) {
 	DB.Create(sameUsers)
 
 	if err := DB.Model(&User{}).Where("name = ?", "count-4").Group("name").Count(&count11).Error; err != nil || count11 != 1 {
-		t.Fatalf("Count should be 3, but got count: %v err %v", count11, err)
+		t.Fatalf("Count should be 1, but got count: %v err %v", count11, err)
 	}
 
 	var count12 int64

tests/create_test.go

@@ -2,6 +2,7 @@ package tests_test
 
 import (
 	"errors"
+	"fmt"
 	"regexp"
 	"testing"
 	"time"
@@ -13,31 +14,48 @@ import (
 )
 
 func TestCreate(t *testing.T) {
-	user := *GetUser("create", Config{})
+	u1 := *GetUser("create", Config{})
 
-	if results := DB.Create(&user); results.Error != nil {
+	if results := DB.Create(&u1); results.Error != nil {
 		t.Fatalf("errors happened when create: %v", results.Error)
 	} else if results.RowsAffected != 1 {
 		t.Fatalf("rows affected expects: %v, got %v", 1, results.RowsAffected)
 	}
 
-	if user.ID == 0 {
+	if u1.ID == 0 {
-		t.Errorf("user's primary key should has value after create, got : %v", user.ID)
+		t.Errorf("user's primary key should has value after create, got : %v", u1.ID)
 	}
 
-	if user.CreatedAt.IsZero() {
+	if u1.CreatedAt.IsZero() {
 		t.Errorf("user's created at should be not zero")
 	}
 
-	if user.UpdatedAt.IsZero() {
+	if u1.UpdatedAt.IsZero() {
 		t.Errorf("user's updated at should be not zero")
 	}
 
 	var newUser User
-	if err := DB.Where("id = ?", user.ID).First(&newUser).Error; err != nil {
+	if err := DB.Where("id = ?", u1.ID).First(&newUser).Error; err != nil {
 		t.Fatalf("errors happened when query: %v", err)
 	} else {
-		CheckUser(t, newUser, user)
+		CheckUser(t, newUser, u1)
+	}
+
+	type user struct {
+		ID   int `gorm:"primaryKey;->:false"`
+		Name string
+		Age  int
+	}
+
+	var u2 user
+	if results := DB.Create(&u2); results.Error != nil {
+		t.Fatalf("errors happened when create: %v", results.Error)
+	} else if results.RowsAffected != 1 {
+		t.Fatalf("rows affected expects: %v, got %v", 1, results.RowsAffected)
+	}
+
+	if u2.ID != 0 {
+		t.Errorf("don't have the permission to read primary key from db, but got %v", u2.ID)
 	}
 }
 
@@ -476,6 +494,13 @@ func TestOmitWithCreate(t *testing.T) {
 	CheckUser(t, result2, user2)
 }
 
+func TestFirstOrCreateNotExistsTable(t *testing.T) {
+	company := Company{Name: "first_or_create_if_not_exists_table"}
+	if err := DB.Table("not_exists").FirstOrCreate(&company).Error; err == nil {
+		t.Errorf("not exists table, but err is nil")
+	}
+}
+
 func TestFirstOrCreateWithPrimaryKey(t *testing.T) {
 	company := Company{ID: 100, Name: "company100_with_primarykey"}
 	DB.FirstOrCreate(&company)
@@ -526,3 +551,260 @@ func TestCreateNilPointer(t *testing.T) {
 		t.Fatalf("it is not ErrInvalidValue")
 	}
 }
+
+func TestFirstOrCreateRowsAffected(t *testing.T) {
+	user := User{Name: "TestFirstOrCreateRowsAffected"}
+
+	res := DB.FirstOrCreate(&user, "name = ?", user.Name)
+	if res.Error != nil || res.RowsAffected != 1 {
+		t.Fatalf("first or create rows affect err:%v rows:%d", res.Error, res.RowsAffected)
+	}
+
+	res = DB.FirstOrCreate(&user, "name = ?", user.Name)
+	if res.Error != nil || res.RowsAffected != 0 {
+		t.Fatalf("first or create rows affect err:%v rows:%d", res.Error, res.RowsAffected)
+	}
+}
+
+func TestCreateWithAutoIncrementCompositeKey(t *testing.T) {
+	type CompositeKeyProduct struct {
+		ProductID    int `gorm:"primaryKey;autoIncrement:true;"` // primary key
+		LanguageCode int `gorm:"primaryKey;"`                    // primary key
+		Code         string
+		Name         string
+	}
+
+	if err := DB.Migrator().DropTable(&CompositeKeyProduct{}); err != nil {
+		t.Fatalf("failed to migrate, got error %v", err)
+	}
+	if err := DB.AutoMigrate(&CompositeKeyProduct{}); err != nil {
+		t.Fatalf("failed to migrate, got error %v", err)
+	}
+
+	prod := &CompositeKeyProduct{
+		LanguageCode: 56,
+		Code:         "Code56",
+		Name:         "ProductName56",
+	}
+	if err := DB.Create(&prod).Error; err != nil {
+		t.Fatalf("failed to create, got error %v", err)
+	}
+
+	newProd := &CompositeKeyProduct{}
+	if err := DB.First(&newProd).Error; err != nil {
+		t.Fatalf("errors happened when query: %v", err)
+	} else {
+		AssertObjEqual(t, newProd, prod, "ProductID", "LanguageCode", "Code", "Name")
+	}
+}
+
+func TestCreateOnConflictWithDefaultNull(t *testing.T) {
+	type OnConflictUser struct {
+		ID     string
+		Name   string `gorm:"default:null"`
+		Email  string
+		Mobile string `gorm:"default:'133xxxx'"`
+	}
+
+	err := DB.Migrator().DropTable(&OnConflictUser{})
+	AssertEqual(t, err, nil)
+	err = DB.AutoMigrate(&OnConflictUser{})
+	AssertEqual(t, err, nil)
+
+	u := OnConflictUser{
+		ID:     "on-conflict-user-id",
+		Name:   "on-conflict-user-name",
+		Email:  "on-conflict-user-email",
+		Mobile: "on-conflict-user-mobile",
+	}
+	err = DB.Create(&u).Error
+	AssertEqual(t, err, nil)
+
+	u.Name = "on-conflict-user-name-2"
+	u.Email = "on-conflict-user-email-2"
+	u.Mobile = ""
+	err = DB.Clauses(clause.OnConflict{UpdateAll: true}).Create(&u).Error
+	AssertEqual(t, err, nil)
+
+	var u2 OnConflictUser
+	err = DB.Where("id = ?", u.ID).First(&u2).Error
+	AssertEqual(t, err, nil)
+	AssertEqual(t, u2.Name, "on-conflict-user-name-2")
+	AssertEqual(t, u2.Email, "on-conflict-user-email-2")
+	AssertEqual(t, u2.Mobile, "133xxxx")
+}
+
+func TestCreateFromMapWithoutPK(t *testing.T) {
+	if !isMysql() {
+		t.Skipf("This test case skipped, because of only supporting for mysql")
+	}
+
+	// case 1: one record, create from map[string]interface{}
+	mapValue1 := map[string]interface{}{"name": "create_from_map_with_schema1", "age": 1}
+	if err := DB.Model(&User{}).Create(mapValue1).Error; err != nil {
+		t.Fatalf("failed to create data from map, got error: %v", err)
+	}
+
+	if _, ok := mapValue1["id"]; !ok {
+		t.Fatal("failed to create data from map with table, returning map has no primary key")
+	}
+
+	var result1 User
+	if err := DB.Where("name = ?", "create_from_map_with_schema1").First(&result1).Error; err != nil || result1.Age != 1 {
+		t.Fatalf("failed to create from map, got error %v", err)
+	}
+
+	var idVal int64
+	_, ok := mapValue1["id"].(uint)
+	if ok {
+		t.Skipf("This test case skipped, because the db supports returning")
+	}
+
+	idVal, ok = mapValue1["id"].(int64)
+	if !ok {
+		t.Fatal("ret result missing id")
+	}
+
+	if int64(result1.ID) != idVal {
+		t.Fatal("failed to create data from map with table, @id != id")
+	}
+
+	// case2: one record, create from *map[string]interface{}
+	mapValue2 := map[string]interface{}{"name": "create_from_map_with_schema2", "age": 1}
+	if err := DB.Model(&User{}).Create(&mapValue2).Error; err != nil {
+		t.Fatalf("failed to create data from map, got error: %v", err)
+	}
+
+	if _, ok := mapValue2["id"]; !ok {
+		t.Fatal("failed to create data from map with table, returning map has no primary key")
+	}
+
+	var result2 User
+	if err := DB.Where("name = ?", "create_from_map_with_schema2").First(&result2).Error; err != nil || result2.Age != 1 {
+		t.Fatalf("failed to create from map, got error %v", err)
+	}
+
+	_, ok = mapValue2["id"].(uint)
+	if ok {
+		t.Skipf("This test case skipped, because the db supports returning")
+	}
+
+	idVal, ok = mapValue2["id"].(int64)
+	if !ok {
+		t.Fatal("ret result missing id")
+	}
+
+	if int64(result2.ID) != idVal {
+		t.Fatal("failed to create data from map with table, @id != id")
+	}
+
+	// case 3: records
+	values := []map[string]interface{}{
+		{"name": "create_from_map_with_schema11", "age": 1}, {"name": "create_from_map_with_schema12", "age": 1},
+	}
+
+	beforeLen := len(values)
+	if err := DB.Model(&User{}).Create(&values).Error; err != nil {
+		t.Fatalf("failed to create data from map, got error: %v", err)
+	}
+
+	// mariadb with returning, values will be appended with id map
+	if len(values) == beforeLen*2 {
+		t.Skipf("This test case skipped, because the db supports returning")
+	}
+
+	for i := range values {
+		v, ok := values[i]["id"]
+		if !ok {
+			t.Fatal("failed to create data from map with table, returning map has no primary key")
+		}
+
+		var result User
+		if err := DB.Where("name = ?", fmt.Sprintf("create_from_map_with_schema1%d", i+1)).First(&result).Error; err != nil || result.Age != 1 {
+			t.Fatalf("failed to create from map, got error %v", err)
+		}
+		if int64(result.ID) != v.(int64) {
+			t.Fatal("failed to create data from map with table, @id != id")
+		}
+	}
+}
+
+func TestCreateFromMapWithTable(t *testing.T) {
+	tableDB := DB.Table("users")
+	supportLastInsertID := isMysql() || isSqlite()
+
+	// case 1: create from map[string]interface{}
+	record := map[string]interface{}{"name": "create_from_map_with_table", "age": 18}
+	if err := tableDB.Create(record).Error; err != nil {
+		t.Fatalf("failed to create data from map with table, got error: %v", err)
+	}
+
+	if _, ok := record["@id"]; !ok && supportLastInsertID {
+		t.Fatal("failed to create data from map with table, returning map has no key '@id'")
+	}
+
+	var res map[string]interface{}
+	if err := tableDB.Select([]string{"id", "name", "age"}).Where("name = ?", "create_from_map_with_table").Find(&res).Error; err != nil || res["age"] != int64(18) {
+		t.Fatalf("failed to create from map, got error %v", err)
+	}
+
+	if _, ok := record["@id"]; ok && fmt.Sprint(res["id"]) != fmt.Sprint(record["@id"]) {
+		t.Fatalf("failed to create data from map with table, @id != id, got %v, expect %v", res["id"], record["@id"])
+	}
+
+	// case 2: create from *map[string]interface{}
+	record1 := map[string]interface{}{"name": "create_from_map_with_table_1", "age": 18}
+	tableDB2 := DB.Table("users")
+	if err := tableDB2.Create(&record1).Error; err != nil {
+		t.Fatalf("failed to create data from map, got error: %v", err)
+	}
+	if _, ok := record1["@id"]; !ok && supportLastInsertID {
+		t.Fatal("failed to create data from map with table, returning map has no key '@id'")
+	}
+
+	var res1 map[string]interface{}
+	if err := tableDB2.Select([]string{"id", "name", "age"}).Where("name = ?", "create_from_map_with_table_1").Find(&res1).Error; err != nil || res1["age"] != int64(18) {
+		t.Fatalf("failed to create from map, got error %v", err)
+	}
+
+	if _, ok := record1["@id"]; ok && fmt.Sprint(res1["id"]) != fmt.Sprint(record1["@id"]) {
+		t.Fatal("failed to create data from map with table, @id != id")
+	}
+
+	// case 3: create from []map[string]interface{}
+	records := []map[string]interface{}{
+		{"name": "create_from_map_with_table_2", "age": 19},
+		{"name": "create_from_map_with_table_3", "age": 20},
+	}
+
+	tableDB = DB.Table("users")
+	if err := tableDB.Create(&records).Error; err != nil {
+		t.Fatalf("failed to create data from slice of map, got error: %v", err)
+	}
+
+	if _, ok := records[0]["@id"]; !ok && supportLastInsertID {
+		t.Fatal("failed to create data from map with table, returning map has no key '@id'")
+	}
+
+	if _, ok := records[1]["@id"]; !ok && supportLastInsertID {
+		t.Fatal("failed to create data from map with table, returning map has no key '@id'")
+	}
+
+	var res2 map[string]interface{}
+	if err := tableDB.Select([]string{"id", "name", "age"}).Where("name = ?", "create_from_map_with_table_2").Find(&res2).Error; err != nil || res2["age"] != int64(19) {
+		t.Fatalf("failed to query data after create from slice of map, got error %v", err)
+	}
+
+	var res3 map[string]interface{}
+	if err := DB.Table("users").Select([]string{"id", "name", "age"}).Where("name = ?", "create_from_map_with_table_3").Find(&res3).Error; err != nil || res3["age"] != int64(20) {
+		t.Fatalf("failed to query data after create from slice of map, got error %v", err)
+	}
+
+	if _, ok := records[0]["@id"]; ok && fmt.Sprint(res2["id"]) != fmt.Sprint(records[0]["@id"]) {
+		t.Errorf("failed to create data from map with table, @id != id, got %v, expect %v", res2["id"], records[0]["@id"])
+	}
+
+	if _, ok := records[1]["id"]; ok && fmt.Sprint(res3["id"]) != fmt.Sprint(records[1]["@id"]) {
+		t.Errorf("failed to create data from map with table, @id != id")
+	}
+}

tests/default_value_test.go

@@ -38,4 +38,22 @@ func TestDefaultValue(t *testing.T) {
 	} else if result.Name != "foo" || result.Name2 != "foo" || result.Name3 != "" || result.Age != 18 || !result.Enabled || result.Created.Format("20060102") != "20000102" {
 		t.Fatalf("Failed to find created data with default data, got %+v", result)
 	}
+
+	type Harumph2 struct {
+		ID      int       `gorm:"default:0"`
+		Email   string    `gorm:"not null;index:,unique"`
+		Name    string    `gorm:"notNull;default:foo"`
+		Name2   string    `gorm:"size:233;not null;default:'foo'"`
+		Name3   string    `gorm:"size:233;notNull;default:''"`
+		Age     int       `gorm:"default:18"`
+		Created time.Time `gorm:"default:2000-01-02"`
+		Enabled bool      `gorm:"default:true"`
+	}
+
+	harumph2 := Harumph2{ID: 2, Email: "hello2@gorm.io"}
+	if err := DB.Table("harumphs").Create(&harumph2).Error; err != nil {
+		t.Fatalf("Failed to create data with default value, got error: %v", err)
+	} else if harumph2.ID != 2 || harumph2.Name != "foo" || harumph2.Name2 != "foo" || harumph2.Name3 != "" || harumph2.Age != 18 || !harumph2.Enabled || harumph2.Created.Format("20060102") != "20000102" {
+		t.Fatalf("Failed to create data with default value, got: %+v", harumph2)
+	}
 }

tests/delete_test.go

@@ -206,9 +206,9 @@ func TestDeleteSliceWithAssociations(t *testing.T) {
 	}
 }
 
-// only sqlite, postgres support returning
+// only sqlite, postgres, gaussdb, sqlserver support returning
 func TestSoftDeleteReturning(t *testing.T) {
-	if DB.Dialector.Name() != "sqlite" && DB.Dialector.Name() != "postgres" {
+	if DB.Dialector.Name() != "sqlite" && DB.Dialector.Name() != "postgres" && DB.Dialector.Name() != "gaussdb" && DB.Dialector.Name() != "sqlserver" {
 		return
 	}
 
@@ -233,7 +233,7 @@ func TestSoftDeleteReturning(t *testing.T) {
 }
 
 func TestDeleteReturning(t *testing.T) {
-	if DB.Dialector.Name() != "sqlite" && DB.Dialector.Name() != "postgres" {
+	if DB.Dialector.Name() != "sqlite" && DB.Dialector.Name() != "postgres" && DB.Dialector.Name() != "gaussdb" && DB.Dialector.Name() != "sqlserver" {
 		return
 	}
 

tests/embedded_struct_test.go

@@ -4,7 +4,9 @@ import (
 	"database/sql/driver"
 	"encoding/json"
 	"errors"
+	"reflect"
 	"testing"
+	"time"
 
 	"gorm.io/gorm"
 	. "gorm.io/gorm/utils/tests"
@@ -36,7 +38,7 @@ func TestEmbeddedStruct(t *testing.T) {
 
 	type EngadgetPost struct {
 		BasePost BasePost `gorm:"Embedded"`
-		Author   Author   `gorm:"Embedded;EmbeddedPrefix:author_"` // Embedded struct
+		Author   *Author  `gorm:"Embedded;EmbeddedPrefix:author_"` // Embedded struct
 		ImageUrl string
 	}
 
@@ -74,13 +76,26 @@ func TestEmbeddedStruct(t *testing.T) {
 		t.Errorf("embedded struct's value should be scanned correctly")
 	}
 
-	DB.Save(&EngadgetPost{BasePost: BasePost{Title: "engadget_news"}})
+	DB.Save(&EngadgetPost{BasePost: BasePost{Title: "engadget_news"}, Author: &Author{Name: "Edward"}})
+	DB.Save(&EngadgetPost{BasePost: BasePost{Title: "engadget_article"}, Author: &Author{Name: "George"}})
 	var egNews EngadgetPost
 	if err := DB.First(&egNews, "title = ?", "engadget_news").Error; err != nil {
 		t.Errorf("no error should happen when query with embedded struct, but got %v", err)
 	} else if egNews.BasePost.Title != "engadget_news" {
 		t.Errorf("embedded struct's value should be scanned correctly")
 	}
+
+	var egPosts []EngadgetPost
+	if err := DB.Order("author_name asc").Find(&egPosts).Error; err != nil {
+		t.Fatalf("no error should happen when query with embedded struct, but got %v", err)
+	}
+	expectAuthors := []string{"Edward", "George"}
+	for i, post := range egPosts {
+		t.Log(i, post.Author)
+		if want := expectAuthors[i]; post.Author.Name != want {
+			t.Errorf("expected author %s got %s", want, post.Author.Name)
+		}
+	}
 }
 
 func TestEmbeddedPointerTypeStruct(t *testing.T) {
@@ -90,9 +105,21 @@ func TestEmbeddedPointerTypeStruct(t *testing.T) {
 		URL   string
 	}
 
+	type Author struct {
+		ID          string
+		Name        string
+		Email       string
+		Age         int
+		Content     Content
+		ContentPtr  *Content
+		Birthday    time.Time
+		BirthdayPtr *time.Time
+	}
+
 	type HNPost struct {
 		*BasePost
 		Upvotes int32
+		*Author `gorm:"EmbeddedPrefix:user_"` // Embedded struct
 	}
 
 	DB.Migrator().DropTable(&HNPost{})
@@ -110,6 +137,52 @@ func TestEmbeddedPointerTypeStruct(t *testing.T) {
 	if hnPost.Title != "embedded_pointer_type" {
 		t.Errorf("Should find correct value for embedded pointer type")
 	}
+
+	if hnPost.Author != nil {
+		t.Errorf("Expected to get back a nil Author but got: %v", hnPost.Author)
+	}
+
+	now := time.Now().Round(time.Second)
+	NewPost := HNPost{
+		BasePost: &BasePost{Title: "embedded_pointer_type2"},
+		Author: &Author{
+			Name:        "test",
+			Content:     Content{"test"},
+			ContentPtr:  nil,
+			Birthday:    now,
+			BirthdayPtr: nil,
+		},
+	}
+	DB.Create(&NewPost)
+
+	hnPost = HNPost{}
+	if err := DB.First(&hnPost, "title = ?", NewPost.Title).Error; err != nil {
+		t.Errorf("No error should happen when find embedded pointer type, but got %v", err)
+	}
+
+	if hnPost.Title != NewPost.Title {
+		t.Errorf("Should find correct value for embedded pointer type")
+	}
+
+	if hnPost.Author.Name != NewPost.Author.Name {
+		t.Errorf("Expected to get Author name %v but got: %v", NewPost.Author.Name, hnPost.Author.Name)
+	}
+
+	if !reflect.DeepEqual(NewPost.Author.Content, hnPost.Author.Content) {
+		t.Errorf("Expected to get Author content %v but got: %v", NewPost.Author.Content, hnPost.Author.Content)
+	}
+
+	if hnPost.Author.ContentPtr != nil {
+		t.Errorf("Expected to get nil Author contentPtr but got: %v", hnPost.Author.ContentPtr)
+	}
+
+	if NewPost.Author.Birthday.UnixMilli() != hnPost.Author.Birthday.UnixMilli() {
+		t.Errorf("Expected to get Author birthday with %+v but got: %+v", NewPost.Author.Birthday, hnPost.Author.Birthday)
+	}
+
+	if hnPost.Author.BirthdayPtr != nil {
+		t.Errorf("Expected to get nil Author birthdayPtr but got: %+v", hnPost.Author.BirthdayPtr)
+	}
 }
 
 type Content struct {
@@ -117,18 +190,26 @@ type Content struct {
 }
 
 func (c Content) Value() (driver.Value, error) {
-	return json.Marshal(c)
+	// mssql driver with issue on handling null bytes https://github.com/denisenkom/go-mssqldb/issues/530,
+	b, err := json.Marshal(c)
+	return string(b[:]), err
 }
 
 func (c *Content) Scan(src interface{}) error {
-	b, ok := src.([]byte)
-	if !ok {
-		return errors.New("Embedded.Scan byte assertion failed")
-	}
-
 	var value Content
-	if err := json.Unmarshal(b, &value); err != nil {
+	str, ok := src.(string)
-		return err
+	if !ok {
+		byt, ok := src.([]byte)
+		if !ok {
+			return errors.New("Embedded.Scan byte assertion failed")
+		}
+		if err := json.Unmarshal(byt, &value); err != nil {
+			return err
+		}
+	} else {
+		if err := json.Unmarshal([]byte(str), &value); err != nil {
+			return err
+		}
 	}
 
 	*c = value
@@ -155,8 +236,15 @@ func TestEmbeddedScanValuer(t *testing.T) {
 }
 
 func TestEmbeddedRelations(t *testing.T) {
+	type EmbUser struct {
+		gorm.Model
+		Name      string
+		Age       uint
+		Languages []Language `gorm:"many2many:EmbUserSpeak;"`
+	}
+
 	type AdvancedUser struct {
-		User     `gorm:"embedded"`
+		EmbUser  `gorm:"embedded"`
 		Advanced bool
 	}
 
@@ -168,3 +256,29 @@ func TestEmbeddedRelations(t *testing.T) {
 		}
 	}
 }
+
+func TestEmbeddedTagSetting(t *testing.T) {
+	type Tag1 struct {
+		Id int64 `gorm:"autoIncrement"`
+	}
+	type Tag2 struct {
+		Id int64
+	}
+
+	type EmbeddedTag struct {
+		Tag1 Tag1 `gorm:"Embedded;"`
+		Tag2 Tag2 `gorm:"Embedded;EmbeddedPrefix:t2_"`
+		Name string
+	}
+
+	DB.Migrator().DropTable(&EmbeddedTag{})
+	err := DB.Migrator().AutoMigrate(&EmbeddedTag{})
+	AssertEqual(t, err, nil)
+
+	t1 := EmbeddedTag{Name: "embedded_tag"}
+	err = DB.Save(&t1).Error
+	AssertEqual(t, err, nil)
+	if t1.Tag1.Id == 0 {
+		t.Errorf("embedded struct's primary field should be rewritten")
+	}
+}