* Hooks (Before/After Create/Save/Update/Delete/Find)
* Eager loading with `Preload`, `Joins`
* Transactions, Nested Transactions, Save Point, RollbackTo to Saved Point
* Context, Prepared Statement Mode, DryRun Mode
* Batch Insert, FindInBatches, Find To Map
* SQL Builder, Upsert, Locking, Optimizer/Index/Comment Hints, NamedArg, Search/Update/Create with SQL Expr
* Composite Primary Key
* Auto Migrations

func (DummyDialector) Initialize(db *gorm.DB) error {
	callbacks.RegisterDefaultCallbacks(db, &callbacks.Config{
		CreateClauses:        []string{"INSERT", "VALUES", "ON CONFLICT", "RETURNING"},
		UpdateClauses:        []string{"UPDATE", "SET", "WHERE", "RETURNING"},
		DeleteClauses:        []string{"DELETE", "FROM", "WHERE", "RETURNING"},
		LastInsertIDReversed: true,
	})

	return nil
}

		{Name: "CreatedAt", DBName: "created_at", BindNames: []string{"Model", "CreatedAt"}, DataType: schema.Time},
		{Name: "UpdatedAt", DBName: "updated_at", BindNames: []string{"Model", "UpdatedAt"}, DataType: schema.Time},
		{Name: "DeletedAt", DBName: "deleted_at", BindNames: []string{"Model", "DeletedAt"}, Tag: `gorm:"index"`, DataType: schema.Time},

	}

	if err := DB.Session(&gorm.Session{AllowGlobalUpdate: true}).Delete(&User{}).Error; err != nil {
		t.Errorf("should returns no error while enable global update, but got err %v", err)
	}
}

func TestDeleteWithAssociations(t *testing.T) {

			appendToRelations(reflectValue.Index(i), reflect.Indirect(reflect.ValueOf(values[i])), clear)

			// TODO support save slice data, sql with case?
			association.Error = associationDB.Updates(reflectValue.Index(i).Addr().Interface()).Error
		}
	case reflect.Struct:
		// clear old data
		if clear && len(values) == 0 {

package clause

type Update struct {
	Modifier string
	Table    Table
}

// Name update clause name
func (update Update) Name() string {
	return "UPDATE"
}

// Build build update clause
func (update Update) Build(builder Builder) {
	if update.Modifier != "" {
		builder.WriteString(update.Modifier)
		builder.WriteByte(' ')
	}

	if update.Table.Name == "" {
		builder.WriteQuoted(currentTable)
	} else {

)

func TestUpdateHasManyAssociations(t *testing.T) {
	user := *GetUser("update-has-many", Config{})

	if err := DB.Create(&user).Error; err != nil {
		t.Fatalf("errors happened when create: %v", err)
	}

	user.Pets = []*Pet{{Name: "pet1"}, {Name: "pet2"}}
	if err := DB.Save(&user).Error; err != nil {
		t.Fatalf("errors happened when update: %v", err)
	}

	var user2 User
	DB.Preload("Pets").Find(&user2, "id = ?", user.ID)

	DB.Save(&animal)
	updatedAt1 := animal.UpdatedAt

	DB.Save(&animal).Update("name", "Francis")
	if updatedAt1.Format(time.RFC3339Nano) == animal.UpdatedAt.Format(time.RFC3339Nano) {
		t.Errorf("UpdatedAt should be updated")
	}

	var animals []Animal
	DB.Find(&animals)
	if count := DB.Model(Animal{}).Where("1=1").Update("CreatedAt", time.Now().Add(2*time.Hour)).RowsAffected; count != int64(len(animals)) {

	}
}

func TestScanNullValue(t *testing.T) {
	user := GetUser("scan_null_value", Config{})
	DB.Create(&user)

	if err := DB.Model(&user).Update("age", nil).Error; err != nil {
		t.Fatalf("failed to update column age for struct, got error %v", err)
	}

	var result User
	if err := DB.First(&result, "id = ?", user.ID).Error; err != nil {

			"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 {