diff --git a/.github/ISSUE_TEMPLATE.md b/.github/ISSUE_TEMPLATE.md
new file mode 100644
index 00000000..a0b64bfa
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE.md
@@ -0,0 +1,45 @@
+Your issue may already be reported! Please search on the [issue track](https://github.com/jinzhu/gorm/issues) before creating one.
+
+### What version of Go are you using (`go version`)?
+
+
+### Which database and its version are you using?
+
+
+### Please provide a complete runnable program to reproduce your issue. **IMPORTANT**
+
+Need to runnable with [GORM's docker compose config](https://github.com/jinzhu/gorm/blob/master/docker-compose.yml) or please provides your config.
+
+```go
+package main
+
+import (
+	"github.com/jinzhu/gorm"
+	_ "github.com/jinzhu/gorm/dialects/mssql"
+	_ "github.com/jinzhu/gorm/dialects/mysql"
+	_ "github.com/jinzhu/gorm/dialects/postgres"
+	_ "github.com/jinzhu/gorm/dialects/sqlite"
+)
+
+var db *gorm.DB
+
+func init() {
+	var err error
+	db, err = gorm.Open("sqlite3", "test.db")
+	// db, err = gorm.Open("postgres", "user=gorm password=gorm DB.name=gorm port=9920 sslmode=disable")
+	// db, err = gorm.Open("mysql", "gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True")
+	// db, err = gorm.Open("mssql", "sqlserver://gorm:LoremIpsum86@localhost:9930?database=gorm")
+	if err != nil {
+		panic(err)
+	}
+	db.LogMode(true)
+}
+
+func main() {
+	if /* failure condition */ {
+		fmt.Println("failed")
+	} else {
+		fmt.Println("success")
+	}
+}
+```
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
new file mode 100644
index 00000000..b467b6ce
--- /dev/null
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -0,0 +1,9 @@
+Make sure these boxes checked before submitting your pull request.
+
+- [] Do only one thing
+- [] No API-breaking changes
+- [] New code/logic commented & tested
+
+For significant changes like big bug fixes, new features, please open an issue to make an agreement on an implementation design/plan first before starting it.
+
+### What did this pull request do?
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
deleted file mode 100644
index 52dbd8b2..00000000
--- a/CONTRIBUTING.md
+++ /dev/null
@@ -1,52 +0,0 @@
-# How to Contribute
-
-## Bug Report
-
-- Do a search on GitHub under Issues in case it has already been reported
-- Submit __executable script__ or failing test pull request that could demonstrates the issue is *MUST HAVE*
-
-## Feature Request
-
-- Feature request with pull request is welcome
-- Or it won't be implemented until I (other developers) find it is helpful for my (their) daily work
-
-## Pull Request
-
-- Prefer single commit pull request, that make the git history can be a bit easier to follow.
-- New features need to be covered with tests to make sure your code works as expected, and won't be broken by others in future
-
-## Contributing to Documentation
-
-- You are welcome ;)
-- You can help improve the README by making them more coherent, consistent or readable, and add more godoc documents to make people easier to follow.
-- Blogs & Usage Guides & PPT also welcome, please add them to https://github.com/jinzhu/gorm/wiki/Guides
-
-### Executable script template
-
-```go
-package main
-
-import (
-	_ "github.com/go-sql-driver/mysql"
-	"github.com/jinzhu/gorm"
-	_ "github.com/lib/pq"
-	_ "github.com/mattn/go-sqlite3"
-)
-
-var db *gorm.DB
-
-func init() {
-	var err error
-	db, err = gorm.Open("sqlite3", "test.db")
-	// db, err = gorm.Open("postgres", "user=username dbname=password sslmode=disable")
-	// db, err = gorm.Open("mysql", "user:password@/dbname?charset=utf8&parseTime=True")
-	if err != nil {
-		panic(err)
-	}
-	db.LogMode(true)
-}
-
-func main() {
-	// Your code
-}
-```
diff --git a/README.md b/README.md
index 44eb4a69..8c6e2302 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,8 @@
 The fantastic ORM library for Golang, aims to be developer friendly.
 
 [![Join the chat at https://gitter.im/jinzhu/gorm](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/jinzhu/gorm?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![wercker status](https://app.wercker.com/status/0cb7bb1039e21b74f8274941428e0921/s/master "wercker status")](https://app.wercker.com/project/bykey/0cb7bb1039e21b74f8274941428e0921)
+[![go report card](https://goreportcard.com/badge/github.com/jinzhu/gorm "go report card")](https://goreportcard.com/report/github.com/jinzhu/gorm)
+[![wercker status](https://app.wercker.com/status/8596cace912c9947dd9c8542ecc8cb8b/s/master "wercker status")](https://app.wercker.com/project/byKey/8596cace912c9947dd9c8542ecc8cb8b)
 [![GoDoc](https://godoc.org/github.com/jinzhu/gorm?status.svg)](https://godoc.org/github.com/jinzhu/gorm)
 
 ## Overview
@@ -31,7 +32,7 @@ The fantastic ORM library for Golang, aims to be developer friendly.
 
 ## Supporting the project
 
-[![http://patreon.com/jinzhu](http://patreon_public_assets.s3.amazonaws.com/sized/becomeAPatronBanner.png)](http://patreon.com/jinzhu)
+[![http://patreon.com/jinzhu](https://c5.patreon.com/external/logo/become_a_patron_button.png)](http://patreon.com/jinzhu)
 
 ## Author
 
diff --git a/association.go b/association.go
index 14fd1c35..3d522ccc 100644
--- a/association.go
+++ b/association.go
@@ -290,7 +290,9 @@ func (association *Association) Count() int {
 		)
 	}
 
-	query.Model(fieldValue).Count(&count)
+	if err := query.Model(fieldValue).Count(&count).Error; err != nil {
+		association.Error = err
+	}
 	return count
 }
 
diff --git a/callback.go b/callback.go
index 17f75451..a4382147 100644
--- a/callback.go
+++ b/callback.go
@@ -1,8 +1,6 @@
 package gorm
 
-import (
-	"fmt"
-)
+import "log"
 
 // DefaultCallback default callbacks defined by gorm
 var DefaultCallback = &Callback{}
@@ -95,7 +93,7 @@ func (cp *CallbackProcessor) Before(callbackName string) *CallbackProcessor {
 func (cp *CallbackProcessor) Register(callbackName string, callback func(scope *Scope)) {
 	if cp.kind == "row_query" {
 		if cp.before == "" && cp.after == "" && callbackName != "gorm:row_query" {
-			fmt.Printf("Registing RowQuery callback %v without specify order with Before(), After(), applying Before('gorm:row_query') by default for compatibility...\n", callbackName)
+			log.Printf("Registing RowQuery callback %v without specify order with Before(), After(), applying Before('gorm:row_query') by default for compatibility...\n", callbackName)
 			cp.before = "gorm:row_query"
 		}
 	}
@@ -109,7 +107,7 @@ func (cp *CallbackProcessor) Register(callbackName string, callback func(scope *
 // Remove a registered callback
 //     db.Callback().Create().Remove("gorm:update_time_stamp_when_create")
 func (cp *CallbackProcessor) Remove(callbackName string) {
-	fmt.Printf("[info] removing callback `%v` from %v\n", callbackName, fileWithLineNum())
+	log.Printf("[info] removing callback `%v` from %v\n", callbackName, fileWithLineNum())
 	cp.name = callbackName
 	cp.remove = true
 	cp.parent.processors = append(cp.parent.processors, cp)
@@ -122,7 +120,7 @@ func (cp *CallbackProcessor) Remove(callbackName string) {
 //		   scope.SetColumn("Updated", now)
 //     })
 func (cp *CallbackProcessor) Replace(callbackName string, callback func(scope *Scope)) {
-	fmt.Printf("[info] replacing callback `%v` from %v\n", callbackName, fileWithLineNum())
+	log.Printf("[info] replacing callback `%v` from %v\n", callbackName, fileWithLineNum())
 	cp.name = callbackName
 	cp.processor = &callback
 	cp.replace = true
@@ -161,7 +159,7 @@ func sortProcessors(cps []*CallbackProcessor) []*func(scope *Scope) {
 	for _, cp := range cps {
 		// show warning message the callback name already exists
 		if index := getRIndex(allNames, cp.name); index > -1 && !cp.replace && !cp.remove {
-			fmt.Printf("[warning] duplicated callback `%v` from %v\n", cp.name, fileWithLineNum())
+			log.Printf("[warning] duplicated callback `%v` from %v\n", cp.name, fileWithLineNum())
 		}
 		allNames = append(allNames, cp.name)
 	}
diff --git a/callback_create.go b/callback_create.go
index f0709880..a4da39e8 100644
--- a/callback_create.go
+++ b/callback_create.go
@@ -32,8 +32,18 @@ func beforeCreateCallback(scope *Scope) {
 func updateTimeStampForCreateCallback(scope *Scope) {
 	if !scope.HasError() {
 		now := NowFunc()
-		scope.SetColumn("CreatedAt", now)
-		scope.SetColumn("UpdatedAt", now)
+
+		if createdAtField, ok := scope.FieldByName("CreatedAt"); ok {
+			if createdAtField.IsBlank {
+				createdAtField.Set(now)
+			}
+		}
+
+		if updatedAtField, ok := scope.FieldByName("UpdatedAt"); ok {
+			if updatedAtField.IsBlank {
+				updatedAtField.Set(now)
+			}
+		}
 	}
 }
 
diff --git a/callback_query.go b/callback_query.go
index 4ed1705e..ba10cc7d 100644
--- a/callback_query.go
+++ b/callback_query.go
@@ -15,6 +15,10 @@ func init() {
 
 // queryCallback used to query data from database
 func queryCallback(scope *Scope) {
+	if _, skip := scope.InstanceGet("gorm:skip_query_callback"); skip {
+		return
+	}
+
 	defer scope.trace(NowFunc())
 
 	var (
@@ -80,9 +84,7 @@ func queryCallback(scope *Scope) {
 
 			if err := rows.Err(); err != nil {
 				scope.Err(err)
-			}
-
-			if scope.db.RowsAffected == 0 && !isSlice {
+			} else if scope.db.RowsAffected == 0 && !isSlice {
 				scope.Err(ErrRecordNotFound)
 			}
 		}
diff --git a/callback_query_preload.go b/callback_query_preload.go
index 76d6f993..30f6b585 100644
--- a/callback_query_preload.go
+++ b/callback_query_preload.go
@@ -4,11 +4,20 @@ import (
 	"errors"
 	"fmt"
 	"reflect"
+	"strconv"
 	"strings"
 )
 
 // preloadCallback used to preload associations
 func preloadCallback(scope *Scope) {
+	if _, skip := scope.InstanceGet("gorm:skip_query_callback"); skip {
+		return
+	}
+
+	if _, ok := scope.Get("gorm:auto_preload"); ok {
+		autoPreload(scope)
+	}
+
 	if scope.Search.preload == nil || scope.HasError() {
 		return
 	}
@@ -79,6 +88,25 @@ func preloadCallback(scope *Scope) {
 	}
 }
 
+func autoPreload(scope *Scope) {
+	for _, field := range scope.Fields() {
+		if field.Relationship == nil {
+			continue
+		}
+
+		if val, ok := field.TagSettings["PRELOAD"]; ok {
+			if preload, err := strconv.ParseBool(val); err != nil {
+				scope.Err(errors.New("invalid preload option"))
+				return
+			} else if !preload {
+				continue
+			}
+		}
+
+		scope.Search.Preload(field.Name)
+	}
+}
+
 func (scope *Scope) generatePreloadDBWithConditions(conditions []interface{}) (*DB, []interface{}) {
 	var (
 		preloadDB         = scope.NewDB()
@@ -264,7 +292,12 @@ func (scope *Scope) handleManyToManyPreload(field *Field, conditions []interface
 
 	// generate query with join table
 	newScope := scope.New(reflect.New(fieldType).Interface())
-	preloadDB = preloadDB.Table(newScope.TableName()).Model(newScope.Value).Select("*")
+	preloadDB = preloadDB.Table(newScope.TableName()).Model(newScope.Value)
+
+	if len(preloadDB.search.selects) == 0 {
+		preloadDB = preloadDB.Select("*")
+	}
+
 	preloadDB = joinTableHandler.JoinWith(joinTableHandler, preloadDB, scope.Value)
 
 	// preload inline conditions
@@ -294,6 +327,10 @@ func (scope *Scope) handleManyToManyPreload(field *Field, conditions []interface
 
 		scope.scan(rows, columns, append(fields, joinTableFields...))
 
+		scope.New(elem.Addr().Interface()).
+			InstanceSet("gorm:skip_query_callback", true).
+			callCallbacks(scope.db.parent.callbacks.queries)
+
 		var foreignKeys = make([]interface{}, len(sourceKeys))
 		// generate hashed forkey keys in join table
 		for idx, joinTableField := range joinTableFields {
diff --git a/create_test.go b/create_test.go
index 7aa181ce..36472914 100644
--- a/create_test.go
+++ b/create_test.go
@@ -5,6 +5,8 @@ import (
 	"reflect"
 	"testing"
 	"time"
+
+	"github.com/jinzhu/now"
 )
 
 func TestCreate(t *testing.T) {
@@ -58,6 +60,34 @@ func TestCreate(t *testing.T) {
 	}
 }
 
+func TestCreateWithExistingTimestamp(t *testing.T) {
+	user := User{Name: "CreateUserExistingTimestamp"}
+
+	timeA := now.MustParse("2016-01-01")
+	user.CreatedAt = timeA
+	user.UpdatedAt = timeA
+	DB.Save(&user)
+
+	if user.CreatedAt.UTC().Format(time.RFC3339) != timeA.UTC().Format(time.RFC3339) {
+		t.Errorf("CreatedAt should not be changed")
+	}
+
+	if user.UpdatedAt.UTC().Format(time.RFC3339) != timeA.UTC().Format(time.RFC3339) {
+		t.Errorf("UpdatedAt should not be changed")
+	}
+
+	var newUser User
+	DB.First(&newUser, user.Id)
+
+	if newUser.CreatedAt.UTC().Format(time.RFC3339) != timeA.UTC().Format(time.RFC3339) {
+		t.Errorf("CreatedAt should not be changed")
+	}
+
+	if newUser.UpdatedAt.UTC().Format(time.RFC3339) != timeA.UTC().Format(time.RFC3339) {
+		t.Errorf("UpdatedAt should not be changed")
+	}
+}
+
 type AutoIncrementUser struct {
 	User
 	Sequence uint `gorm:"AUTO_INCREMENT"`
diff --git a/dialect.go b/dialect.go
index e879588b..fe8e2f62 100644
--- a/dialect.go
+++ b/dialect.go
@@ -33,6 +33,8 @@ type Dialect interface {
 	HasTable(tableName string) bool
 	// HasColumn check has column or not
 	HasColumn(tableName string, columnName string) bool
+	// ModifyColumn modify column's type
+	ModifyColumn(tableName string, columnName string, typ string) error
 
 	// LimitAndOffsetSQL return generated SQL with Limit and Offset, as mssql has special case
 	LimitAndOffsetSQL(limit, offset interface{}) string
@@ -41,8 +43,8 @@ type Dialect interface {
 	// LastInsertIdReturningSuffix most dbs support LastInsertId, but postgres needs to use `RETURNING`
 	LastInsertIDReturningSuffix(tableName, columnName string) string
 
-	// BuildForeignKeyName returns a foreign key name for the given table, field and reference
-	BuildForeignKeyName(tableName, field, dest string) string
+	// BuildKeyName returns a valid key name (foreign key, index key) for the given table, field and reference
+	BuildKeyName(kind, tableName string, fields ...string) string
 
 	// CurrentDatabase return current database name
 	CurrentDatabase() string
@@ -114,3 +116,11 @@ var ParseFieldStructForDialect = func(field *StructField, dialect Dialect) (fiel
 
 	return fieldValue, dataType, size, strings.TrimSpace(additionalType)
 }
+
+func currentDatabaseAndTable(dialect Dialect, tableName string) (string, string) {
+	if strings.Contains(tableName, ".") {
+		splitStrings := strings.SplitN(tableName, ".", 2)
+		return splitStrings[0], splitStrings[1]
+	}
+	return dialect.CurrentDatabase(), tableName
+}
diff --git a/dialect_common.go b/dialect_common.go
index 1554151c..1e5e3b61 100644
--- a/dialect_common.go
+++ b/dialect_common.go
@@ -31,13 +31,20 @@ func (s *commonDialect) SetDB(db SQLCommon) {
 }
 
 func (commonDialect) BindVar(i int) string {
-	return "$$" // ?
+	return "$$$" // ?
 }
 
 func (commonDialect) Quote(key string) string {
 	return fmt.Sprintf(`"%s"`, key)
 }
 
+func (s *commonDialect) fieldCanAutoIncrement(field *StructField) bool {
+	if value, ok := field.TagSettings["AUTO_INCREMENT"]; ok {
+		return value != "FALSE"
+	}
+	return field.IsPrimaryKey
+}
+
 func (s *commonDialect) DataTypeOf(field *StructField) string {
 	var dataValue, sqlType, size, additionalType = ParseFieldStructForDialect(field, s)
 
@@ -46,13 +53,13 @@ func (s *commonDialect) DataTypeOf(field *StructField) string {
 		case reflect.Bool:
 			sqlType = "BOOLEAN"
 		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok {
+			if s.fieldCanAutoIncrement(field) {
 				sqlType = "INTEGER AUTO_INCREMENT"
 			} else {
 				sqlType = "INTEGER"
 			}
 		case reflect.Int64, reflect.Uint64:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok {
+			if s.fieldCanAutoIncrement(field) {
 				sqlType = "BIGINT AUTO_INCREMENT"
 			} else {
 				sqlType = "BIGINT"
@@ -92,7 +99,8 @@ func (s *commonDialect) DataTypeOf(field *StructField) string {
 
 func (s commonDialect) HasIndex(tableName string, indexName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.STATISTICS WHERE table_schema = ? AND table_name = ? AND index_name = ?", s.CurrentDatabase(), tableName, indexName).Scan(&count)
+	currentDatabase, tableName := currentDatabaseAndTable(&s, tableName)
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.STATISTICS WHERE table_schema = ? AND table_name = ? AND index_name = ?", currentDatabase, tableName, indexName).Scan(&count)
 	return count > 0
 }
 
@@ -107,16 +115,23 @@ func (s commonDialect) HasForeignKey(tableName string, foreignKeyName string) bo
 
 func (s commonDialect) HasTable(tableName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = ? AND table_name = ?", s.CurrentDatabase(), tableName).Scan(&count)
+	currentDatabase, tableName := currentDatabaseAndTable(&s, tableName)
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = ? AND table_name = ?", currentDatabase, tableName).Scan(&count)
 	return count > 0
 }
 
 func (s commonDialect) HasColumn(tableName string, columnName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE table_schema = ? AND table_name = ? AND column_name = ?", s.CurrentDatabase(), tableName, columnName).Scan(&count)
+	currentDatabase, tableName := currentDatabaseAndTable(&s, tableName)
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE table_schema = ? AND table_name = ? AND column_name = ?", currentDatabase, tableName, columnName).Scan(&count)
 	return count > 0
 }
 
+func (s commonDialect) ModifyColumn(tableName string, columnName string, typ string) error {
+	_, err := s.db.Exec(fmt.Sprintf("ALTER TABLE %v ALTER COLUMN %v TYPE %v", tableName, columnName, typ))
+	return err
+}
+
 func (s commonDialect) CurrentDatabase() (name string) {
 	s.db.QueryRow("SELECT DATABASE()").Scan(&name)
 	return
@@ -124,12 +139,12 @@ func (s commonDialect) CurrentDatabase() (name string) {
 
 func (commonDialect) LimitAndOffsetSQL(limit, offset interface{}) (sql string) {
 	if limit != nil {
-		if parsedLimit, err := strconv.ParseInt(fmt.Sprint(limit), 0, 0); err == nil && parsedLimit > 0 {
+		if parsedLimit, err := strconv.ParseInt(fmt.Sprint(limit), 0, 0); err == nil && parsedLimit >= 0 {
 			sql += fmt.Sprintf(" LIMIT %d", parsedLimit)
 		}
 	}
 	if offset != nil {
-		if parsedOffset, err := strconv.ParseInt(fmt.Sprint(offset), 0, 0); err == nil && parsedOffset > 0 {
+		if parsedOffset, err := strconv.ParseInt(fmt.Sprint(offset), 0, 0); err == nil && parsedOffset >= 0 {
 			sql += fmt.Sprintf(" OFFSET %d", parsedOffset)
 		}
 	}
@@ -144,8 +159,14 @@ func (commonDialect) LastInsertIDReturningSuffix(tableName, columnName string) s
 	return ""
 }
 
-func (DefaultForeignKeyNamer) BuildForeignKeyName(tableName, field, dest string) string {
-	keyName := fmt.Sprintf("%s_%s_%s_foreign", tableName, field, dest)
-	keyName = regexp.MustCompile("(_*[^a-zA-Z]+_*|_+)").ReplaceAllString(keyName, "_")
+// BuildKeyName returns a valid key name (foreign key, index key) for the given table, field and reference
+func (DefaultForeignKeyNamer) BuildKeyName(kind, tableName string, fields ...string) string {
+	keyName := fmt.Sprintf("%s_%s_%s", kind, tableName, strings.Join(fields, "_"))
+	keyName = regexp.MustCompile("[^a-zA-Z0-9]+").ReplaceAllString(keyName, "_")
 	return keyName
 }
+
+// IsByteArrayOrSlice returns true of the reflected value is an array or slice
+func IsByteArrayOrSlice(value reflect.Value) bool {
+	return (value.Kind() == reflect.Array || value.Kind() == reflect.Slice) && value.Type().Elem() == reflect.TypeOf(uint8(0))
+}
diff --git a/dialect_mysql.go b/dialect_mysql.go
index b471a162..1feed1f6 100644
--- a/dialect_mysql.go
+++ b/dialect_mysql.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"reflect"
 	"regexp"
+	"strconv"
 	"strings"
 	"time"
 	"unicode/utf8"
@@ -42,29 +43,43 @@ func (s *mysql) DataTypeOf(field *StructField) string {
 		switch dataValue.Kind() {
 		case reflect.Bool:
 			sqlType = "boolean"
-		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
+		case reflect.Int8:
+			if s.fieldCanAutoIncrement(field) {
+				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
+				sqlType = "tinyint AUTO_INCREMENT"
+			} else {
+				sqlType = "tinyint"
+			}
+		case reflect.Int, reflect.Int16, reflect.Int32:
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "int AUTO_INCREMENT"
 			} else {
 				sqlType = "int"
 			}
-		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
+		case reflect.Uint8:
+			if s.fieldCanAutoIncrement(field) {
+				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
+				sqlType = "tinyint unsigned AUTO_INCREMENT"
+			} else {
+				sqlType = "tinyint unsigned"
+			}
+		case reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "int unsigned AUTO_INCREMENT"
 			} else {
 				sqlType = "int unsigned"
 			}
 		case reflect.Int64:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "bigint AUTO_INCREMENT"
 			} else {
 				sqlType = "bigint"
 			}
 		case reflect.Uint64:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "bigint unsigned AUTO_INCREMENT"
 			} else {
@@ -80,14 +95,19 @@ func (s *mysql) DataTypeOf(field *StructField) string {
 			}
 		case reflect.Struct:
 			if _, ok := dataValue.Interface().(time.Time); ok {
+				precision := ""
+				if p, ok := field.TagSettings["PRECISION"]; ok {
+					precision = fmt.Sprintf("(%s)", p)
+				}
+
 				if _, ok := field.TagSettings["NOT NULL"]; ok {
-					sqlType = "timestamp"
+					sqlType = fmt.Sprintf("timestamp%v", precision)
 				} else {
-					sqlType = "timestamp NULL"
+					sqlType = fmt.Sprintf("timestamp%v NULL", precision)
 				}
 			}
 		default:
-			if _, ok := dataValue.Interface().([]byte); ok {
+			if IsByteArrayOrSlice(dataValue) {
 				if size > 0 && size < 65532 {
 					sqlType = fmt.Sprintf("varbinary(%d)", size)
 				} else {
@@ -112,9 +132,30 @@ func (s mysql) RemoveIndex(tableName string, indexName string) error {
 	return err
 }
 
+func (s mysql) ModifyColumn(tableName string, columnName string, typ string) error {
+	_, err := s.db.Exec(fmt.Sprintf("ALTER TABLE %v MODIFY COLUMN %v %v", tableName, columnName, typ))
+	return err
+}
+
+func (s mysql) LimitAndOffsetSQL(limit, offset interface{}) (sql string) {
+	if limit != nil {
+		if parsedLimit, err := strconv.ParseInt(fmt.Sprint(limit), 0, 0); err == nil && parsedLimit >= 0 {
+			sql += fmt.Sprintf(" LIMIT %d", parsedLimit)
+
+			if offset != nil {
+				if parsedOffset, err := strconv.ParseInt(fmt.Sprint(offset), 0, 0); err == nil && parsedOffset >= 0 {
+					sql += fmt.Sprintf(" OFFSET %d", parsedOffset)
+				}
+			}
+		}
+	}
+	return
+}
+
 func (s mysql) HasForeignKey(tableName string, foreignKeyName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_SCHEMA=? AND TABLE_NAME=? AND CONSTRAINT_NAME=? AND CONSTRAINT_TYPE='FOREIGN KEY'", s.CurrentDatabase(), tableName, foreignKeyName).Scan(&count)
+	currentDatabase, tableName := currentDatabaseAndTable(&s, tableName)
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_SCHEMA=? AND TABLE_NAME=? AND CONSTRAINT_NAME=? AND CONSTRAINT_TYPE='FOREIGN KEY'", currentDatabase, tableName, foreignKeyName).Scan(&count)
 	return count > 0
 }
 
@@ -127,8 +168,8 @@ func (mysql) SelectFromDummyTable() string {
 	return "FROM DUAL"
 }
 
-func (s mysql) BuildForeignKeyName(tableName, field, dest string) string {
-	keyName := s.commonDialect.BuildForeignKeyName(tableName, field, dest)
+func (s mysql) BuildKeyName(kind, tableName string, fields ...string) string {
+	keyName := s.commonDialect.BuildKeyName(kind, tableName, fields...)
 	if utf8.RuneCountInString(keyName) <= 64 {
 		return keyName
 	}
@@ -136,8 +177,8 @@ func (s mysql) BuildForeignKeyName(tableName, field, dest string) string {
 	h.Write([]byte(keyName))
 	bs := h.Sum(nil)
 
-	// sha1 is 40 digits, keep first 24 characters of destination
-	destRunes := []rune(regexp.MustCompile("(_*[^a-zA-Z]+_*|_+)").ReplaceAllString(dest, "_"))
+	// sha1 is 40 characters, keep first 24 characters of destination
+	destRunes := []rune(regexp.MustCompile("[^a-zA-Z0-9]+").ReplaceAllString(fields[0], "_"))
 	if len(destRunes) > 24 {
 		destRunes = destRunes[:24]
 	}
diff --git a/dialect_postgres.go b/dialect_postgres.go
index 7d07a02c..c44c6a5b 100644
--- a/dialect_postgres.go
+++ b/dialect_postgres.go
@@ -1,6 +1,7 @@
 package gorm
 
 import (
+	"encoding/json"
 	"fmt"
 	"reflect"
 	"strings"
@@ -13,6 +14,7 @@ type postgres struct {
 
 func init() {
 	RegisterDialect("postgres", &postgres{})
+	RegisterDialect("cloudsqlpostgres", &postgres{})
 }
 
 func (postgres) GetName() string {
@@ -30,15 +32,15 @@ func (s *postgres) DataTypeOf(field *StructField) string {
 		switch dataValue.Kind() {
 		case reflect.Bool:
 			sqlType = "boolean"
-		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uintptr:
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "serial"
 			} else {
 				sqlType = "integer"
 			}
-		case reflect.Int64, reflect.Uint64:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
+		case reflect.Int64, reflect.Uint32, reflect.Uint64:
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "bigserial"
 			} else {
@@ -65,10 +67,16 @@ func (s *postgres) DataTypeOf(field *StructField) string {
 				sqlType = "hstore"
 			}
 		default:
-			if isByteArrayOrSlice(dataValue) {
+			if IsByteArrayOrSlice(dataValue) {
 				sqlType = "bytea"
-			} else if isUUID(dataValue) {
-				sqlType = "uuid"
+
+				if isUUID(dataValue) {
+					sqlType = "uuid"
+				}
+
+				if isJSON(dataValue) {
+					sqlType = "jsonb"
+				}
 			}
 		}
 	}
@@ -85,7 +93,7 @@ func (s *postgres) DataTypeOf(field *StructField) string {
 
 func (s postgres) HasIndex(tableName string, indexName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM pg_indexes WHERE tablename = $1 AND indexname = $2", tableName, indexName).Scan(&count)
+	s.db.QueryRow("SELECT count(*) FROM pg_indexes WHERE tablename = $1 AND indexname = $2 AND schemaname = CURRENT_SCHEMA()", tableName, indexName).Scan(&count)
 	return count > 0
 }
 
@@ -97,13 +105,13 @@ func (s postgres) HasForeignKey(tableName string, foreignKeyName string) bool {
 
 func (s postgres) HasTable(tableName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = $1 AND table_type = 'BASE TABLE'", tableName).Scan(&count)
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = $1 AND table_type = 'BASE TABLE' AND table_schema = CURRENT_SCHEMA()", tableName).Scan(&count)
 	return count > 0
 }
 
 func (s postgres) HasColumn(tableName string, columnName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.columns WHERE table_name = $1 AND column_name = $2", tableName, columnName).Scan(&count)
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.columns WHERE table_name = $1 AND column_name = $2 AND table_schema = CURRENT_SCHEMA()", tableName, columnName).Scan(&count)
 	return count > 0
 }
 
@@ -120,10 +128,6 @@ func (postgres) SupportLastInsertID() bool {
 	return false
 }
 
-func isByteArrayOrSlice(value reflect.Value) bool {
-	return (value.Kind() == reflect.Array || value.Kind() == reflect.Slice) && value.Type().Elem() == reflect.TypeOf(uint8(0))
-}
-
 func isUUID(value reflect.Value) bool {
 	if value.Kind() != reflect.Array || value.Type().Len() != 16 {
 		return false
@@ -132,3 +136,8 @@ func isUUID(value reflect.Value) bool {
 	lower := strings.ToLower(typename)
 	return "uuid" == lower || "guid" == lower
 }
+
+func isJSON(value reflect.Value) bool {
+	_, ok := value.Interface().(json.RawMessage)
+	return ok
+}
diff --git a/dialect_sqlite3.go b/dialect_sqlite3.go
index 46edea0c..f26f6be3 100644
--- a/dialect_sqlite3.go
+++ b/dialect_sqlite3.go
@@ -28,14 +28,14 @@ func (s *sqlite3) DataTypeOf(field *StructField) string {
 		case reflect.Bool:
 			sqlType = "bool"
 		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
-			if field.IsPrimaryKey {
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "integer primary key autoincrement"
 			} else {
 				sqlType = "integer"
 			}
 		case reflect.Int64, reflect.Uint64:
-			if field.IsPrimaryKey {
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "integer primary key autoincrement"
 			} else {
@@ -54,7 +54,7 @@ func (s *sqlite3) DataTypeOf(field *StructField) string {
 				sqlType = "datetime"
 			}
 		default:
-			if _, ok := dataValue.Interface().([]byte); ok {
+			if IsByteArrayOrSlice(dataValue) {
 				sqlType = "blob"
 			}
 		}
diff --git a/dialects/mssql/mssql.go b/dialects/mssql/mssql.go
index f9087495..1dd5fb69 100644
--- a/dialects/mssql/mssql.go
+++ b/dialects/mssql/mssql.go
@@ -50,11 +50,11 @@ func (s *mssql) SetDB(db gorm.SQLCommon) {
 }
 
 func (mssql) BindVar(i int) string {
-	return "$$" // ?
+	return "$$$" // ?
 }
 
 func (mssql) Quote(key string) string {
-	return fmt.Sprintf(`"%s"`, key)
+	return fmt.Sprintf(`[%s]`, key)
 }
 
 func (s *mssql) DataTypeOf(field *gorm.StructField) string {
@@ -65,14 +65,14 @@ func (s *mssql) DataTypeOf(field *gorm.StructField) string {
 		case reflect.Bool:
 			sqlType = "bit"
 		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "int IDENTITY(1,1)"
 			} else {
 				sqlType = "int"
 			}
 		case reflect.Int64, reflect.Uint64:
-			if _, ok := field.TagSettings["AUTO_INCREMENT"]; ok || field.IsPrimaryKey {
+			if s.fieldCanAutoIncrement(field) {
 				field.TagSettings["AUTO_INCREMENT"] = "AUTO_INCREMENT"
 				sqlType = "bigint IDENTITY(1,1)"
 			} else {
@@ -81,21 +81,21 @@ func (s *mssql) DataTypeOf(field *gorm.StructField) string {
 		case reflect.Float32, reflect.Float64:
 			sqlType = "float"
 		case reflect.String:
-			if size > 0 && size < 65532 {
+			if size > 0 && size < 8000 {
 				sqlType = fmt.Sprintf("nvarchar(%d)", size)
 			} else {
-				sqlType = "text"
+				sqlType = "nvarchar(max)"
 			}
 		case reflect.Struct:
 			if _, ok := dataValue.Interface().(time.Time); ok {
-				sqlType = "datetime2"
+				sqlType = "datetimeoffset"
 			}
 		default:
-			if _, ok := dataValue.Interface().([]byte); ok {
-				if size > 0 && size < 65532 {
-					sqlType = fmt.Sprintf("varchar(%d)", size)
+			if gorm.IsByteArrayOrSlice(dataValue) {
+				if size > 0 && size < 8000 {
+					sqlType = fmt.Sprintf("varbinary(%d)", size)
 				} else {
-					sqlType = "text"
+					sqlType = "varbinary(max)"
 				}
 			}
 		}
@@ -111,6 +111,13 @@ func (s *mssql) DataTypeOf(field *gorm.StructField) string {
 	return fmt.Sprintf("%v %v", sqlType, additionalType)
 }
 
+func (s mssql) fieldCanAutoIncrement(field *gorm.StructField) bool {
+	if value, ok := field.TagSettings["AUTO_INCREMENT"]; ok {
+		return value != "FALSE"
+	}
+	return field.IsPrimaryKey
+}
+
 func (s mssql) HasIndex(tableName string, indexName string) bool {
 	var count int
 	s.db.QueryRow("SELECT count(*) FROM sys.indexes WHERE name=? AND object_id=OBJECT_ID(?)", indexName, tableName).Scan(&count)
@@ -128,16 +135,23 @@ func (s mssql) HasForeignKey(tableName string, foreignKeyName string) bool {
 
 func (s mssql) HasTable(tableName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = ? AND table_catalog = ?", tableName, s.CurrentDatabase()).Scan(&count)
+	currentDatabase, tableName := currentDatabaseAndTable(&s, tableName)
+	s.db.QueryRow("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_name = ? AND table_catalog = ?", tableName, currentDatabase).Scan(&count)
 	return count > 0
 }
 
 func (s mssql) HasColumn(tableName string, columnName string) bool {
 	var count int
-	s.db.QueryRow("SELECT count(*) FROM information_schema.columns WHERE table_catalog = ? AND table_name = ? AND column_name = ?", s.CurrentDatabase(), tableName, columnName).Scan(&count)
+	currentDatabase, tableName := currentDatabaseAndTable(&s, tableName)
+	s.db.QueryRow("SELECT count(*) FROM information_schema.columns WHERE table_catalog = ? AND table_name = ? AND column_name = ?", currentDatabase, tableName, columnName).Scan(&count)
 	return count > 0
 }
 
+func (s mssql) ModifyColumn(tableName string, columnName string, typ string) error {
+	_, err := s.db.Exec(fmt.Sprintf("ALTER TABLE %v ALTER COLUMN %v %v", tableName, columnName, typ))
+	return err
+}
+
 func (s mssql) CurrentDatabase() (name string) {
 	s.db.QueryRow("SELECT DB_NAME() AS [Current Database]").Scan(&name)
 	return
@@ -145,12 +159,12 @@ func (s mssql) CurrentDatabase() (name string) {
 
 func (mssql) LimitAndOffsetSQL(limit, offset interface{}) (sql string) {
 	if offset != nil {
-		if parsedOffset, err := strconv.ParseInt(fmt.Sprint(offset), 0, 0); err == nil && parsedOffset > 0 {
+		if parsedOffset, err := strconv.ParseInt(fmt.Sprint(offset), 0, 0); err == nil && parsedOffset >= 0 {
 			sql += fmt.Sprintf(" OFFSET %d ROWS", parsedOffset)
 		}
 	}
 	if limit != nil {
-		if parsedLimit, err := strconv.ParseInt(fmt.Sprint(limit), 0, 0); err == nil && parsedLimit > 0 {
+		if parsedLimit, err := strconv.ParseInt(fmt.Sprint(limit), 0, 0); err == nil && parsedLimit >= 0 {
 			if sql == "" {
 				// add default zero offset
 				sql += " OFFSET 0 ROWS"
@@ -168,3 +182,11 @@ func (mssql) SelectFromDummyTable() string {
 func (mssql) LastInsertIDReturningSuffix(tableName, columnName string) string {
 	return ""
 }
+
+func currentDatabaseAndTable(dialect gorm.Dialect, tableName string) (string, string) {
+	if strings.Contains(tableName, ".") {
+		splitStrings := strings.SplitN(tableName, ".", 2)
+		return splitStrings[0], splitStrings[1]
+	}
+	return dialect.CurrentDatabase(), tableName
+}
diff --git a/dialects/postgres/postgres.go b/dialects/postgres/postgres.go
index adeeec7b..1d0dcb60 100644
--- a/dialects/postgres/postgres.go
+++ b/dialects/postgres/postgres.go
@@ -6,6 +6,9 @@ import (
 
 	_ "github.com/lib/pq"
 	"github.com/lib/pq/hstore"
+	"encoding/json"
+	"errors"
+	"fmt"
 )
 
 type Hstore map[string]*string
@@ -52,3 +55,26 @@ func (h *Hstore) Scan(value interface{}) error {
 
 	return nil
 }
+
+// Jsonb Postgresql's JSONB data type
+type Jsonb struct {
+	json.RawMessage
+}
+
+// Value get value of Jsonb
+func (j Jsonb) Value() (driver.Value, error) {
+	if len(j.RawMessage) == 0 {
+		return nil, nil
+	}
+	return j.MarshalJSON()
+}
+
+// Scan scan value into Jsonb
+func (j *Jsonb) Scan(value interface{}) error {
+	bytes, ok := value.([]byte)
+	if !ok {
+		return errors.New(fmt.Sprint("Failed to unmarshal JSONB value:", value))
+	}
+
+	return json.Unmarshal(bytes, j)
+}
diff --git a/docker-compose.yml b/docker-compose.yml
new file mode 100644
index 00000000..79bf5fc3
--- /dev/null
+++ b/docker-compose.yml
@@ -0,0 +1,30 @@
+version: '3'
+
+services:
+  mysql:
+    image: 'mysql:latest'
+    ports:
+      - 9910:3306
+    environment:
+      - MYSQL_DATABASE=gorm
+      - MYSQL_USER=gorm
+      - MYSQL_PASSWORD=gorm
+      - MYSQL_RANDOM_ROOT_PASSWORD="yes"
+  postgres:
+    image: 'postgres:latest'
+    ports:
+      - 9920:5432
+    environment:
+      - POSTGRES_USER=gorm
+      - POSTGRES_DB=gorm
+      - POSTGRES_PASSWORD=gorm
+  mssql:
+    image: 'mcmoe/mssqldocker:latest'
+    ports:
+      - 9930:1433
+    environment:
+      - ACCEPT_EULA=Y
+      - SA_PASSWORD=LoremIpsum86
+      - MSSQL_DB=gorm
+      - MSSQL_USER=gorm
+      - MSSQL_PASSWORD=LoremIpsum86
diff --git a/errors.go b/errors.go
index 832fa9b0..6845188e 100644
--- a/errors.go
+++ b/errors.go
@@ -29,6 +29,10 @@ func (errs Errors) GetErrors() []error {
 // Add adds an error
 func (errs Errors) Add(newErrors ...error) Errors {
 	for _, err := range newErrors {
+		if err == nil {
+			continue
+		}
+
 		if errors, ok := err.(Errors); ok {
 			errs = errs.Add(errors...)
 		} else {
diff --git a/join_table_handler.go b/join_table_handler.go
index 18c12a85..2d1a5055 100644
--- a/join_table_handler.go
+++ b/join_table_handler.go
@@ -59,6 +59,7 @@ func (s *JoinTableHandler) Setup(relationship *Relationship, tableName string, s
 	s.TableName = tableName
 
 	s.Source = JoinTableSource{ModelType: source}
+	s.Source.ForeignKeys = []JoinTableForeignKey{}
 	for idx, dbName := range relationship.ForeignFieldNames {
 		s.Source.ForeignKeys = append(s.Source.ForeignKeys, JoinTableForeignKey{
 			DBName:            relationship.ForeignDBNames[idx],
@@ -67,6 +68,7 @@ func (s *JoinTableHandler) Setup(relationship *Relationship, tableName string, s
 	}
 
 	s.Destination = JoinTableSource{ModelType: destination}
+	s.Destination.ForeignKeys = []JoinTableForeignKey{}
 	for idx, dbName := range relationship.AssociationForeignFieldNames {
 		s.Destination.ForeignKeys = append(s.Destination.ForeignKeys, JoinTableForeignKey{
 			DBName:            relationship.AssociationForeignDBNames[idx],
diff --git a/join_table_test.go b/join_table_test.go
index f083ab02..6d5f427d 100644
--- a/join_table_test.go
+++ b/join_table_test.go
@@ -80,3 +80,38 @@ func TestJoinTable(t *testing.T) {
 		t.Errorf("Should deleted all addresses")
 	}
 }
+
+func TestEmbeddedMany2ManyRelationship(t *testing.T) {
+	type EmbeddedPerson struct {
+		ID        int
+		Name      string
+		Addresses []*Address `gorm:"many2many:person_addresses;"`
+	}
+
+	type NewPerson struct {
+		EmbeddedPerson
+		ExternalID uint
+	}
+	DB.Exec("drop table person_addresses;")
+	DB.AutoMigrate(&NewPerson{})
+
+	address1 := &Address{Address1: "address 1"}
+	address2 := &Address{Address1: "address 2"}
+	person := &NewPerson{ExternalID: 100, EmbeddedPerson: EmbeddedPerson{Name: "person", Addresses: []*Address{address1, address2}}}
+	if err := DB.Save(person).Error; err != nil {
+		t.Errorf("no error should return when save embedded many2many relationship, but got %v", err)
+	}
+
+	if err := DB.Model(person).Association("Addresses").Delete(address1).Error; err != nil {
+		t.Errorf("no error should return when delete embedded many2many relationship, but got %v", err)
+	}
+
+	association := DB.Model(person).Association("Addresses")
+	if count := association.Count(); count != 1 || association.Error != nil {
+		t.Errorf("Should found one address, but got %v, error is %v", count, association.Error)
+	}
+
+	if association.Clear(); association.Count() != 0 {
+		t.Errorf("Should deleted all addresses")
+	}
+}
diff --git a/logger.go b/logger.go
index 117b0403..4324a2e4 100644
--- a/logger.go
+++ b/logger.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	"reflect"
 	"regexp"
+	"strconv"
 	"time"
 	"unicode"
 )
@@ -87,6 +88,7 @@ var LogFormatter = func(values ...interface{}) (messages []interface{}) {
 			}
 
 			messages = append(messages, sql)
+			messages = append(messages, fmt.Sprintf(" \n\033[36;31m[%v]\033[0m ", strconv.FormatInt(values[5].(int64), 10)+" rows affected or returned "))
 		} else {
 			messages = append(messages, "\033[31;1m")
 			messages = append(messages, values[2:]...)
diff --git a/main.go b/main.go
index 9ae560a1..b23ae2f2 100644
--- a/main.go
+++ b/main.go
@@ -71,11 +71,13 @@ func Open(dialect string, args ...interface{}) (db *DB, err error) {
 		dialect:   newDialect(dialect, dbSQL),
 	}
 	db.parent = db
-
-	if err == nil {
-		// Send a ping to make sure the database connection is alive.
-		if err = db.DB().Ping(); err != nil {
-			db.DB().Close()
+	if err != nil {
+		return
+	}
+	// Send a ping to make sure the database connection is alive.
+	if d, ok := dbSQL.(*sql.DB); ok {
+		if err = d.Ping(); err != nil {
+			d.Close()
 		}
 	}
 	return
@@ -166,6 +168,15 @@ func (s *DB) NewScope(value interface{}) *Scope {
 	return &Scope{db: dbClone, Search: dbClone.search.clone(), Value: value}
 }
 
+// QueryExpr returns the query as expr object
+func (s *DB) QueryExpr() *expr {
+	scope := s.NewScope(s.Value)
+	scope.InstanceSet("skip_bindvar", true)
+	scope.prepareQuerySQL()
+
+	return Expr(scope.SQL, scope.SQLVars...)
+}
+
 // Where return a new relation, filter records with given conditions, accepts `map`, `struct` or `string` as conditions, refer http://jinzhu.github.io/gorm/crud.html#query
 func (s *DB) Where(query interface{}, args ...interface{}) *DB {
 	return s.clone().search.Where(query, args...).db
@@ -216,7 +227,7 @@ func (s *DB) Group(query string) *DB {
 }
 
 // Having specify HAVING conditions for GROUP BY
-func (s *DB) Having(query string, values ...interface{}) *DB {
+func (s *DB) Having(query interface{}, values ...interface{}) *DB {
 	return s.clone().search.Having(query, values...).db
 }
 
@@ -452,7 +463,7 @@ func (s *DB) Debug() *DB {
 // Begin begin a transaction
 func (s *DB) Begin() *DB {
 	c := s.clone()
-	if db, ok := c.db.(sqlDb); ok {
+	if db, ok := c.db.(sqlDb); ok && db != nil {
 		tx, err := db.Begin()
 		c.db = interface{}(tx).(SQLCommon)
 		c.AddError(err)
@@ -464,7 +475,7 @@ func (s *DB) Begin() *DB {
 
 // Commit commit a transaction
 func (s *DB) Commit() *DB {
-	if db, ok := s.db.(sqlTx); ok {
+	if db, ok := s.db.(sqlTx); ok && db != nil {
 		s.AddError(db.Commit())
 	} else {
 		s.AddError(ErrInvalidTransaction)
@@ -474,7 +485,7 @@ func (s *DB) Commit() *DB {
 
 // Rollback rollback a transaction
 func (s *DB) Rollback() *DB {
-	if db, ok := s.db.(sqlTx); ok {
+	if db, ok := s.db.(sqlTx); ok && db != nil {
 		s.AddError(db.Rollback())
 	} else {
 		s.AddError(ErrInvalidTransaction)
@@ -600,6 +611,14 @@ func (s *DB) AddForeignKey(field string, dest string, onDelete string, onUpdate
 	return scope.db
 }
 
+// RemoveForeignKey Remove foreign key from the given scope, e.g:
+//     db.Model(&User{}).RemoveForeignKey("city_id", "cities(id)")
+func (s *DB) RemoveForeignKey(field string, dest string) *DB {
+	scope := s.clone().NewScope(s.Value)
+	scope.removeForeignKey(field, dest)
+	return scope.db
+}
+
 // Association start `Association Mode` to handler relations things easir in that mode, refer: https://jinzhu.github.io/gorm/associations.html#association-mode
 func (s *DB) Association(column string) *Association {
 	var err error
@@ -700,7 +719,7 @@ func (s *DB) GetErrors() []error {
 ////////////////////////////////////////////////////////////////////////////////
 
 func (s *DB) clone() *DB {
-	db := DB{
+	db := &DB{
 		db:                s.db,
 		parent:            s.parent,
 		logger:            s.logger,
@@ -721,8 +740,8 @@ func (s *DB) clone() *DB {
 		db.search = s.search.clone()
 	}
 
-	db.search.db = &db
-	return &db
+	db.search.db = db
+	return db
 }
 
 func (s *DB) print(v ...interface{}) {
@@ -737,6 +756,6 @@ func (s *DB) log(v ...interface{}) {
 
 func (s *DB) slog(sql string, t time.Time, vars ...interface{}) {
 	if s.logMode == 2 {
-		s.print("sql", fileWithLineNum(), NowFunc().Sub(t), sql, vars)
+		s.print("sql", fileWithLineNum(), NowFunc().Sub(t), sql, vars, s.RowsAffected)
 	}
 }
diff --git a/main_test.go b/main_test.go
index 3b1433cf..83e6f7aa 100644
--- a/main_test.go
+++ b/main_test.go
@@ -36,27 +36,20 @@ func init() {
 }
 
 func OpenTestConnection() (db *gorm.DB, err error) {
+	dbDSN := os.Getenv("GORM_DSN")
 	switch os.Getenv("GORM_DIALECT") {
 	case "mysql":
-		// CREATE USER 'gorm'@'localhost' IDENTIFIED BY 'gorm';
-		// CREATE DATABASE gorm;
-		// GRANT ALL ON gorm.* TO 'gorm'@'localhost';
 		fmt.Println("testing mysql...")
-		dbhost := os.Getenv("GORM_DBADDRESS")
-		if dbhost != "" {
-			dbhost = fmt.Sprintf("tcp(%v)", dbhost)
+		if dbDSN == "" {
+			dbDSN = "gorm:gorm@tcp(localhost:9910)/gorm?charset=utf8&parseTime=True"
 		}
-		db, err = gorm.Open("mysql", fmt.Sprintf("gorm:gorm@%v/gorm?charset=utf8&parseTime=True", dbhost))
+		db, err = gorm.Open("mysql", dbDSN)
 	case "postgres":
 		fmt.Println("testing postgres...")
-		dbhost := os.Getenv("GORM_DBHOST")
-		if dbhost != "" {
-			dbhost = fmt.Sprintf("host=%v ", dbhost)
+		if dbDSN == "" {
+			dbDSN = "user=gorm password=gorm DB.name=gorm port=9920 sslmode=disable"
 		}
-		db, err = gorm.Open("postgres", fmt.Sprintf("%vuser=gorm password=gorm DB.name=gorm sslmode=disable", dbhost))
-	case "foundation":
-		fmt.Println("testing foundation...")
-		db, err = gorm.Open("foundation", "dbname=gorm port=15432 sslmode=disable")
+		db, err = gorm.Open("postgres", dbDSN)
 	case "mssql":
 		// CREATE LOGIN gorm WITH PASSWORD = 'LoremIpsum86';
 		// CREATE DATABASE gorm;
@@ -64,7 +57,10 @@ func OpenTestConnection() (db *gorm.DB, err error) {
 		// CREATE USER gorm FROM LOGIN gorm;
 		// sp_changedbowner 'gorm';
 		fmt.Println("testing mssql...")
-		db, err = gorm.Open("mssql", "sqlserver://gorm:LoremIpsum86@localhost:1433?database=gorm")
+		if dbDSN == "" {
+			dbDSN = "sqlserver://gorm:LoremIpsum86@localhost:9930?database=gorm"
+		}
+		db, err = gorm.Open("mssql", dbDSN)
 	default:
 		fmt.Println("testing sqlite3...")
 		db, err = gorm.Open("sqlite3", filepath.Join(os.TempDir(), "gorm.db"))
@@ -72,8 +68,10 @@ func OpenTestConnection() (db *gorm.DB, err error) {
 
 	// db.SetLogger(Logger{log.New(os.Stdout, "\r\n", 0)})
 	// db.SetLogger(log.New(os.Stdout, "\r\n", 0))
-	if os.Getenv("DEBUG") == "true" {
+	if debug := os.Getenv("DEBUG"); debug == "true" {
 		db.LogMode(true)
+	} else if debug == "false" {
+		db.LogMode(false)
 	}
 
 	db.DB().SetMaxIdleConns(10)
@@ -607,9 +605,54 @@ func TestHaving(t *testing.T) {
 	}
 }
 
+func TestQueryBuilderSubselectInWhere(t *testing.T) {
+	user := User{Name: "query_expr_select_ruser1", Email: "root@user1.com", Age: 32}
+	DB.Save(&user)
+	user = User{Name: "query_expr_select_ruser2", Email: "nobody@user2.com", Age: 16}
+	DB.Save(&user)
+	user = User{Name: "query_expr_select_ruser3", Email: "root@user3.com", Age: 64}
+	DB.Save(&user)
+	user = User{Name: "query_expr_select_ruser4", Email: "somebody@user3.com", Age: 128}
+	DB.Save(&user)
+
+	var users []User
+	DB.Select("*").Where("name IN (?)", DB.
+		Select("name").Table("users").Where("name LIKE ?", "query_expr_select%").QueryExpr()).Find(&users)
+
+	if len(users) != 4 {
+		t.Errorf("Four users should be found, instead found %d", len(users))
+	}
+
+	DB.Select("*").Where("name LIKE ?", "query_expr_select%").Where("age >= (?)", DB.
+		Select("AVG(age)").Table("users").Where("name LIKE ?", "query_expr_select%").QueryExpr()).Find(&users)
+
+	if len(users) != 2 {
+		t.Errorf("Two users should be found, instead found %d", len(users))
+	}
+}
+
+func TestQueryBuilderSubselectInHaving(t *testing.T) {
+	user := User{Name: "query_expr_having_ruser1", Email: "root@user1.com", Age: 64}
+	DB.Save(&user)
+	user = User{Name: "query_expr_having_ruser2", Email: "root@user2.com", Age: 128}
+	DB.Save(&user)
+	user = User{Name: "query_expr_having_ruser3", Email: "root@user1.com", Age: 64}
+	DB.Save(&user)
+	user = User{Name: "query_expr_having_ruser4", Email: "root@user2.com", Age: 128}
+	DB.Save(&user)
+
+	var users []User
+	DB.Select("AVG(age) as avgage").Where("name LIKE ?", "query_expr_having_%").Group("email").Having("AVG(age) > (?)", DB.
+		Select("AVG(age)").Where("name LIKE ?", "query_expr_having_%").Table("users").QueryExpr()).Find(&users)
+
+	if len(users) != 1 {
+		t.Errorf("Two user group should be found, instead found %d", len(users))
+	}
+}
+
 func DialectHasTzSupport() bool {
 	// NB: mssql and FoundationDB do not support time zones.
-	if dialect := os.Getenv("GORM_DIALECT"); dialect == "mssql" || dialect == "foundation" {
+	if dialect := os.Getenv("GORM_DIALECT"); dialect == "foundation" {
 		return false
 	}
 	return true
diff --git a/migration_test.go b/migration_test.go
index 9fc14fa0..6b4470a6 100644
--- a/migration_test.go
+++ b/migration_test.go
@@ -5,6 +5,7 @@ import (
 	"database/sql/driver"
 	"errors"
 	"fmt"
+	"os"
 	"reflect"
 	"testing"
 	"time"
@@ -432,3 +433,24 @@ func TestMultipleIndexes(t *testing.T) {
 		t.Error("MultipleIndexes unique index failed")
 	}
 }
+
+func TestModifyColumnType(t *testing.T) {
+	if dialect := os.Getenv("GORM_DIALECT"); dialect != "postgres" && dialect != "mysql" && dialect != "mssql" {
+		t.Skip("Skipping this because only postgres, mysql and mssql support altering a column type")
+	}
+
+	type ModifyColumnType struct {
+		gorm.Model
+		Name1 string `gorm:"length:100"`
+		Name2 string `gorm:"length:200"`
+	}
+	DB.DropTable(&ModifyColumnType{})
+	DB.CreateTable(&ModifyColumnType{})
+
+	name2Field, _ := DB.NewScope(&ModifyColumnType{}).FieldByName("Name2")
+	name2Type := DB.Dialect().DataTypeOf(name2Field.StructField)
+
+	if err := DB.Model(&ModifyColumnType{}).ModifyColumn("name1", name2Type).Error; err != nil {
+		t.Errorf("No error should happen when ModifyColumn, but got %v", err)
+	}
+}
diff --git a/model_struct.go b/model_struct.go
index d4a46784..315028c4 100644
--- a/model_struct.go
+++ b/model_struct.go
@@ -97,7 +97,11 @@ func (structField *StructField) clone() *StructField {
 		TagSettings:     map[string]string{},
 		Struct:          structField.Struct,
 		IsForeignKey:    structField.IsForeignKey,
-		Relationship:    structField.Relationship,
+	}
+
+	if structField.Relationship != nil {
+		relationship := *structField.Relationship
+		clone.Relationship = &relationship
 	}
 
 	for key, value := range structField.TagSettings {
@@ -219,6 +223,15 @@ func (scope *Scope) GetModelStruct() *ModelStruct {
 								subField.IsPrimaryKey = false
 							}
 						}
+
+						if subField.Relationship != nil && subField.Relationship.JoinTableHandler != nil {
+							if joinTableHandler, ok := subField.Relationship.JoinTableHandler.(*JoinTableHandler); ok {
+								newJoinTableHandler := &JoinTableHandler{}
+								newJoinTableHandler.Setup(subField.Relationship, joinTableHandler.TableName, reflectType, joinTableHandler.Destination.ModelType)
+								subField.Relationship.JoinTableHandler = newJoinTableHandler
+							}
+						}
+
 						modelStruct.StructFields = append(modelStruct.StructFields, subField)
 					}
 					continue
diff --git a/preload_test.go b/preload_test.go
index c830025c..311ad0be 100644
--- a/preload_test.go
+++ b/preload_test.go
@@ -96,6 +96,33 @@ func TestPreload(t *testing.T) {
 	}
 }
 
+func TestAutoPreload(t *testing.T) {
+	user1 := getPreloadUser("auto_user1")
+	DB.Save(user1)
+
+	preloadDB := DB.Set("gorm:auto_preload", true).Where("role = ?", "Preload")
+	var user User
+	preloadDB.Find(&user)
+	checkUserHasPreloadData(user, t)
+
+	user2 := getPreloadUser("auto_user2")
+	DB.Save(user2)
+
+	var users []User
+	preloadDB.Find(&users)
+
+	for _, user := range users {
+		checkUserHasPreloadData(user, t)
+	}
+
+	var users2 []*User
+	preloadDB.Find(&users2)
+
+	for _, user := range users2 {
+		checkUserHasPreloadData(*user, t)
+	}
+}
+
 func TestNestedPreload1(t *testing.T) {
 	type (
 		Level1 struct {
@@ -1600,6 +1627,48 @@ func TestPrefixedPreloadDuplication(t *testing.T) {
 	}
 }
 
+func TestPreloadManyToManyCallbacks(t *testing.T) {
+	type (
+		Level2 struct {
+			ID   uint
+			Name string
+		}
+		Level1 struct {
+			ID      uint
+			Name    string
+			Level2s []Level2 `gorm:"many2many:level1_level2s;AssociationForeignKey:ID;ForeignKey:ID"`
+		}
+	)
+
+	DB.DropTableIfExists("level1_level2s")
+	DB.DropTableIfExists(new(Level1))
+	DB.DropTableIfExists(new(Level2))
+
+	if err := DB.AutoMigrate(new(Level1), new(Level2)).Error; err != nil {
+		t.Error(err)
+	}
+
+	lvl := Level1{
+		Name: "l1",
+		Level2s: []Level2{
+			Level2{Name: "l2-1"}, Level2{Name: "l2-2"},
+		},
+	}
+	DB.Save(&lvl)
+
+	called := 0
+
+	DB.Callback().Query().After("gorm:query").Register("TestPreloadManyToManyCallbacks", func(scope *gorm.Scope) {
+		called = called + 1
+	})
+
+	DB.Preload("Level2s").First(&Level1{}, "id = ?", lvl.ID)
+
+	if called != 3 {
+		t.Errorf("Wanted callback to be called 3 times but got %d", called)
+	}
+}
+
 func toJSONString(v interface{}) []byte {
 	r, _ := json.MarshalIndent(v, "", "  ")
 	return r
diff --git a/query_test.go b/query_test.go
index 9531b33e..def84e04 100644
--- a/query_test.go
+++ b/query_test.go
@@ -222,7 +222,7 @@ func TestSearchWithStruct(t *testing.T) {
 	}
 
 	DB.First(&user, User{Name: user1.Name})
-	if user.Id == 0 || user.Name != user.Name {
+	if user.Id == 0 || user.Name != user1.Name {
 		t.Errorf("Search first record with inline struct")
 	}
 
diff --git a/scope.go b/scope.go
index 29cb01b2..a10cb3a2 100644
--- a/scope.go
+++ b/scope.go
@@ -253,15 +253,25 @@ func (scope *Scope) CallMethod(methodName string) {
 
 // AddToVars add value as sql's vars, used to prevent SQL injection
 func (scope *Scope) AddToVars(value interface{}) string {
+	_, skipBindVar := scope.InstanceGet("skip_bindvar")
+
 	if expr, ok := value.(*expr); ok {
 		exp := expr.expr
 		for _, arg := range expr.args {
-			exp = strings.Replace(exp, "?", scope.AddToVars(arg), 1)
+			if skipBindVar {
+				scope.AddToVars(arg)
+			} else {
+				exp = strings.Replace(exp, "?", scope.AddToVars(arg), 1)
+			}
 		}
 		return exp
 	}
 
 	scope.SQLVars = append(scope.SQLVars, value)
+
+	if skipBindVar {
+		return "?"
+	}
 	return scope.Dialect().BindVar(len(scope.SQLVars))
 }
 
@@ -329,18 +339,18 @@ func (scope *Scope) QuotedTableName() (name string) {
 
 // CombinedConditionSql return combined condition sql
 func (scope *Scope) CombinedConditionSql() string {
-	joinSql := scope.joinsSQL()
-	whereSql := scope.whereSQL()
+	joinSQL := scope.joinsSQL()
+	whereSQL := scope.whereSQL()
 	if scope.Search.raw {
-		whereSql = strings.TrimSuffix(strings.TrimPrefix(whereSql, "WHERE ("), ")")
+		whereSQL = strings.TrimSuffix(strings.TrimPrefix(whereSQL, "WHERE ("), ")")
 	}
-	return joinSql + whereSql + scope.groupSQL() +
+	return joinSQL + whereSQL + scope.groupSQL() +
 		scope.havingSQL() + scope.orderSQL() + scope.limitAndOffsetSQL()
 }
 
 // Raw set raw sql
 func (scope *Scope) Raw(sql string) *Scope {
-	scope.SQL = strings.Replace(sql, "$$", "?", -1)
+	scope.SQL = strings.Replace(sql, "$$$", "?", -1)
 	return scope
 }
 
@@ -448,8 +458,8 @@ func (scope *Scope) callMethod(methodName string, reflectValue reflect.Value) {
 }
 
 var (
-	columnRegexp        = regexp.MustCompile("^[a-zA-Z]+(\\.[a-zA-Z]+)*$") // only match string like `name`, `users.name`
-	isNumberRegexp      = regexp.MustCompile("^\\s*\\d+\\s*$")             // match if string is number
+	columnRegexp        = regexp.MustCompile("^[a-zA-Z\\d]+(\\.[a-zA-Z\\d]+)*$") // only match string like `name`, `users.name`
+	isNumberRegexp      = regexp.MustCompile("^\\s*\\d+\\s*$")                   // match if string is number
 	comparisonRegexp    = regexp.MustCompile("(?i) (=|<>|>|<|LIKE|IS|IN) ")
 	countingQueryRegexp = regexp.MustCompile("(?i)^count(.+)$")
 )
@@ -1129,7 +1139,7 @@ func (scope *Scope) dropTable() *Scope {
 }
 
 func (scope *Scope) modifyColumn(column string, typ string) {
-	scope.Raw(fmt.Sprintf("ALTER TABLE %v MODIFY %v %v", scope.QuotedTableName(), scope.Quote(column), typ)).Exec()
+	scope.db.AddError(scope.Dialect().ModifyColumn(scope.QuotedTableName(), scope.Quote(column), typ))
 }
 
 func (scope *Scope) dropColumn(column string) {
@@ -1155,7 +1165,8 @@ func (scope *Scope) addIndex(unique bool, indexName string, column ...string) {
 }
 
 func (scope *Scope) addForeignKey(field string, dest string, onDelete string, onUpdate string) {
-	keyName := scope.Dialect().BuildForeignKeyName(scope.TableName(), field, dest)
+	// Compatible with old generated key
+	keyName := scope.Dialect().BuildKeyName(scope.TableName(), field, dest, "foreign")
 
 	if scope.Dialect().HasForeignKey(scope.TableName(), keyName) {
 		return
@@ -1164,6 +1175,16 @@ func (scope *Scope) addForeignKey(field string, dest string, onDelete string, on
 	scope.Raw(fmt.Sprintf(query, scope.QuotedTableName(), scope.quoteIfPossible(keyName), scope.quoteIfPossible(field), dest, onDelete, onUpdate)).Exec()
 }
 
+func (scope *Scope) removeForeignKey(field string, dest string) {
+	keyName := scope.Dialect().BuildKeyName(scope.TableName(), field, dest)
+
+	if !scope.Dialect().HasForeignKey(scope.TableName(), keyName) {
+		return
+	}
+	var query = `ALTER TABLE %s DROP CONSTRAINT %s;`
+	scope.Raw(fmt.Sprintf(query, scope.QuotedTableName(), scope.quoteIfPossible(keyName))).Exec()
+}
+
 func (scope *Scope) removeIndex(indexName string) {
 	scope.Dialect().RemoveIndex(scope.TableName(), indexName)
 }
@@ -1199,7 +1220,7 @@ func (scope *Scope) autoIndex() *Scope {
 
 			for _, name := range names {
 				if name == "INDEX" || name == "" {
-					name = fmt.Sprintf("idx_%v_%v", scope.TableName(), field.DBName)
+					name = scope.Dialect().BuildKeyName("idx", scope.TableName(), field.DBName)
 				}
 				indexes[name] = append(indexes[name], field.DBName)
 			}
@@ -1210,7 +1231,7 @@ func (scope *Scope) autoIndex() *Scope {
 
 			for _, name := range names {
 				if name == "UNIQUE_INDEX" || name == "" {
-					name = fmt.Sprintf("uix_%v_%v", scope.TableName(), field.DBName)
+					name = scope.Dialect().BuildKeyName("uix", scope.TableName(), field.DBName)
 				}
 				uniqueIndexes[name] = append(uniqueIndexes[name], field.DBName)
 			}
@@ -1218,11 +1239,15 @@ func (scope *Scope) autoIndex() *Scope {
 	}
 
 	for name, columns := range indexes {
-		scope.NewDB().Model(scope.Value).AddIndex(name, columns...)
+		if db := scope.NewDB().Model(scope.Value).AddIndex(name, columns...); db.Error != nil {
+			scope.db.AddError(db.Error)
+		}
 	}
 
 	for name, columns := range uniqueIndexes {
-		scope.NewDB().Model(scope.Value).AddUniqueIndex(name, columns...)
+		if db := scope.NewDB().Model(scope.Value).AddUniqueIndex(name, columns...); db.Error != nil {
+			scope.db.AddError(db.Error)
+		}
 	}
 
 	return scope
diff --git a/search.go b/search.go
index 23dac2c3..90138595 100644
--- a/search.go
+++ b/search.go
@@ -2,7 +2,6 @@ package gorm
 
 import (
 	"fmt"
-	"regexp"
 )
 
 type search struct {
@@ -73,13 +72,7 @@ func (s *search) Order(value interface{}, reorder ...bool) *search {
 	return s
 }
 
-var distinctSQLRegexp = regexp.MustCompile(`(?i)distinct[^a-z]+[a-z]+`)
-
 func (s *search) Select(query interface{}, args ...interface{}) *search {
-	if distinctSQLRegexp.MatchString(fmt.Sprint(query)) {
-		s.ignoreOrderQuery = true
-	}
-
 	s.selects = map[string]interface{}{"query": query, "args": args}
 	return s
 }
@@ -104,8 +97,12 @@ func (s *search) Group(query string) *search {
 	return s
 }
 
-func (s *search) Having(query string, values ...interface{}) *search {
-	s.havingConditions = append(s.havingConditions, map[string]interface{}{"query": query, "args": values})
+func (s *search) Having(query interface{}, values ...interface{}) *search {
+	if val, ok := query.(*expr); ok {
+		s.havingConditions = append(s.havingConditions, map[string]interface{}{"query": val.expr, "args": val.args})
+	} else {
+		s.havingConditions = append(s.havingConditions, map[string]interface{}{"query": query, "args": values})
+	}
 	return s
 }
 
diff --git a/test_all.sh b/test_all.sh
index 7e752051..5cfb3321 100755
--- a/test_all.sh
+++ b/test_all.sh
@@ -1,5 +1,5 @@
-dialects=("postgres" "mysql" "sqlite" "mssql")
+dialects=("postgres" "mysql" "mssql" "sqlite")
 
 for dialect in "${dialects[@]}" ; do
-    GORM_DIALECT=${dialect} go test
+    DEBUG=false GORM_DIALECT=${dialect} go test
 done
diff --git a/utils.go b/utils.go
index ee663f34..dfaae939 100644
--- a/utils.go
+++ b/utils.go
@@ -23,7 +23,7 @@ var NowFunc = func() time.Time {
 }
 
 // Copied from golint
-var commonInitialisms = []string{"API", "ASCII", "CPU", "CSS", "DNS", "EOF", "GUID", "HTML", "HTTP", "HTTPS", "ID", "IP", "JSON", "LHS", "QPS", "RAM", "RHS", "RPC", "SLA", "SMTP", "SSH", "TLS", "TTL", "UI", "UID", "UUID", "URI", "URL", "UTF8", "VM", "XML", "XSRF", "XSS"}
+var commonInitialisms = []string{"API", "ASCII", "CPU", "CSS", "DNS", "EOF", "GUID", "HTML", "HTTP", "HTTPS", "ID", "IP", "JSON", "LHS", "QPS", "RAM", "RHS", "RPC", "SLA", "SMTP", "SSH", "TLS", "TTL", "UID", "UI", "UUID", "URI", "URL", "UTF8", "VM", "XML", "XSRF", "XSS"}
 var commonInitialismsReplacer *strings.Replacer
 
 var goSrcRegexp = regexp.MustCompile(`jinzhu/gorm/.*.go`)
@@ -97,6 +97,9 @@ func ToDBName(name string) string {
 				}
 			} else {
 				buf.WriteRune(v)
+				if i == len(value)-2 && nextCase == upper {
+					buf.WriteRune('_')
+				}
 			}
 		} else {
 			currCase = upper
diff --git a/utils_test.go b/utils_test.go
index 07f5b17f..152296d2 100644
--- a/utils_test.go
+++ b/utils_test.go
@@ -9,11 +9,13 @@ import (
 func TestToDBNameGenerateFriendlyName(t *testing.T) {
 	var maps = map[string]string{
 		"":                          "",
+		"X":                         "x",
 		"ThisIsATest":               "this_is_a_test",
 		"PFAndESI":                  "pf_and_esi",
 		"AbcAndJkl":                 "abc_and_jkl",
 		"EmployeeID":                "employee_id",
 		"SKU_ID":                    "sku_id",
+		"FieldX":                    "field_x",
 		"HTTPAndSMTP":               "http_and_smtp",
 		"HTTPServerHandlerForURLID": "http_server_handler_for_url_id",
 		"UUID":     "uuid",
diff --git a/wercker.yml b/wercker.yml
index ff6fb17c..2f2370b3 100644
--- a/wercker.yml
+++ b/wercker.yml
@@ -2,17 +2,79 @@
 box: golang
 
 services:
-    - id: mariadb:10.0
+    - name: mariadb
+      id: mariadb:latest
       env:
           MYSQL_DATABASE: gorm
           MYSQL_USER: gorm
           MYSQL_PASSWORD: gorm
           MYSQL_RANDOM_ROOT_PASSWORD: "yes"
-    - id: postgres
+    - name: mysql
+      id: mysql:8
+      env:
+          MYSQL_DATABASE: gorm
+          MYSQL_USER: gorm
+          MYSQL_PASSWORD: gorm
+          MYSQL_RANDOM_ROOT_PASSWORD: "yes"
+    - name: mysql57
+      id: mysql:5.7
+      env:
+          MYSQL_DATABASE: gorm
+          MYSQL_USER: gorm
+          MYSQL_PASSWORD: gorm
+          MYSQL_RANDOM_ROOT_PASSWORD: "yes"
+    - name: mysql56
+      id: mysql:5.6
+      env:
+          MYSQL_DATABASE: gorm
+          MYSQL_USER: gorm
+          MYSQL_PASSWORD: gorm
+          MYSQL_RANDOM_ROOT_PASSWORD: "yes"
+    - name: mysql55
+      id: mysql:5.5
+      env:
+          MYSQL_DATABASE: gorm
+          MYSQL_USER: gorm
+          MYSQL_PASSWORD: gorm
+          MYSQL_RANDOM_ROOT_PASSWORD: "yes"
+    - name: postgres
+      id: postgres:latest
       env:
           POSTGRES_USER: gorm
           POSTGRES_PASSWORD: gorm
           POSTGRES_DB: gorm
+    - name: postgres96
+      id: postgres:9.6
+      env:
+          POSTGRES_USER: gorm
+          POSTGRES_PASSWORD: gorm
+          POSTGRES_DB: gorm
+    - name: postgres95
+      id: postgres:9.5
+      env:
+          POSTGRES_USER: gorm
+          POSTGRES_PASSWORD: gorm
+          POSTGRES_DB: gorm
+    - name: postgres94
+      id: postgres:9.4
+      env:
+          POSTGRES_USER: gorm
+          POSTGRES_PASSWORD: gorm
+          POSTGRES_DB: gorm
+    - name: postgres93
+      id: postgres:9.3
+      env:
+          POSTGRES_USER: gorm
+          POSTGRES_PASSWORD: gorm
+          POSTGRES_DB: gorm
+    - name: mssql
+      id: mcmoe/mssqldocker:latest
+      env:
+        ACCEPT_EULA: Y
+        SA_PASSWORD: LoremIpsum86
+        MSSQL_DB: gorm
+        MSSQL_USER: gorm
+        MSSQL_PASSWORD: LoremIpsum86
 
 # The steps that will be executed in the build pipeline
 build:
@@ -42,12 +104,57 @@ build:
                 code: |
                     go test ./...
 
+        - script:
+                name: test mariadb
+                code: |
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mariadb:3306)/gorm?charset=utf8&parseTime=True" go test ./...
+
         - script:
                 name: test mysql
                 code: |
-                    GORM_DIALECT=mysql GORM_DBADDRESS=mariadb:3306 go test ./...
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql:3306)/gorm?charset=utf8&parseTime=True" go test ./...
+
+        - script:
+                name: test mysql5.7
+                code: |
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql57:3306)/gorm?charset=utf8&parseTime=True" go test ./...
+
+        - script:
+                name: test mysql5.6
+                code: |
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql56:3306)/gorm?charset=utf8&parseTime=True" go test ./...
+
+        - script:
+                name: test mysql5.5
+                code: |
+                    GORM_DIALECT=mysql GORM_DSN="gorm:gorm@tcp(mysql55:3306)/gorm?charset=utf8&parseTime=True" go test ./...
 
         - script:
                 name: test postgres
                 code: |
-                    GORM_DIALECT=postgres GORM_DBHOST=postgres go test ./...
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+
+        - script:
+                name: test postgres96
+                code: |
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres96 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+
+        - script:
+                name: test postgres95
+                code: |
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres95 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+
+        - script:
+                name: test postgres94
+                code: |
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres94 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+
+        - script:
+                name: test postgres93
+                code: |
+                    GORM_DIALECT=postgres GORM_DSN="host=postgres93 user=gorm password=gorm DB.name=gorm port=5432 sslmode=disable" go test ./...
+
+        - script:
+                name: test mssql
+                code: |
+                    GORM_DIALECT=mssql GORM_DSN="sqlserver://gorm:LoremIpsum86@mssql:1433?database=gorm" go test ./...