// create sequence
	err = DB.Table("events").AutoMigrate(&Event1{})
	if err != nil {
		t.Errorf("AutoMigrate err:%v", err)
	}

	// delete sequence
	err = DB.Table("events").AutoMigrate(&Event{})
	if err != nil {
		t.Errorf("AutoMigrate err:%v", err)
	}

	// update sequence
	err = DB.Table("events").AutoMigrate(&Event1{})
	if err != nil {
		t.Errorf("AutoMigrate err:%v", err)
	}

	for len(tx.Statement.scopes) > 0 {
		tx = tx.executeScopes()
	}

	return tx.Dialector.Migrator(tx.Session(&Session{}))
}

// AutoMigrate run auto migration for given models
func (db *DB) AutoMigrate(dst ...interface{}) error {
	return db.Migrator().AutoMigrate(dst...)
}

// ViewOption view option
type ViewOption struct {
	Replace     bool   // If true, exec `CREATE`. If false, exec `CREATE OR REPLACE`

			Level1   Level1
			Level3ID uint
		}
		Level3 struct {
			ID     uint
			Name   string
			Level2 Level2
		}
	)
	DB.Migrator().DropTable(&Level3{}, &Level2{}, &Level1{})
	if err := DB.AutoMigrate(&Level3{}, &Level2{}, &Level1{}); err != nil {
		t.Error(err)
	}

	want := Level3{Level2: Level2{Level1: Level1{Value: "value"}}}
	if err := DB.Create(&want).Error; err != nil {
		t.Error(err)
	}

	if DB.Dialector.Name() != "gaussdb" {
		t.Skip()
	}
	DB.Migrator().DropTable(&Company{})
	DB.AutoMigrate(Company{})
	if err := DB.Table("companies").Migrator().AlterColumn(CompanyNew{}, "name"); err != nil {
		t.Fatalf("failed to alter column from string to int, got error %v", err)
	}

	DB.AutoMigrate(Company{})

}

func TestRunCallbacks(t *testing.T) {
	DB.Migrator().DropTable(&Product{})
	DB.AutoMigrate(&Product{})

	p := Product{Code: "unique_code", Price: 100}
	DB.Save(&p)

	if !reflect.DeepEqual(p.GetCallTimes(), []int64{1, 1, 0, 1, 1, 0, 0, 0, 0}) {

		BasePost BasePost `gorm:"Embedded"`
		Author   *Author  `gorm:"Embedded;EmbeddedPrefix:author_"` // Embedded struct
		ImageUrl string
	}

	DB.Migrator().DropTable(&HNPost{}, &EngadgetPost{})
	if err := DB.Migrator().AutoMigrate(&HNPost{}, &EngadgetPost{}); err != nil {
		t.Fatalf("failed to auto migrate, got error: %v", err)
	}

	for _, name := range []string{"author_id", "author_name", "author_email"} {

}

func TestSerializer(t *testing.T) {
	schema.RegisterSerializer("custom", NewCustomSerializer("hello"))
	DB.Migrator().DropTable(adaptorSerializerModel(&SerializerStruct{}))
	if err := DB.Migrator().AutoMigrate(adaptorSerializerModel(&SerializerStruct{})); err != nil {
		t.Fatalf("no error should happen when migrate scanner, valuer struct, got error %v", err)
	}

	createdAt := time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC)

	if supported, found := dialectors[db.Dialector.Name()]; !(found && supported) {
		return
	}

	DB.Migrator().DropTable(&City{})

	if err = db.AutoMigrate(&City{}); err != nil {
		t.Fatalf("failed to migrate cities table, got error: %v", err)
	}

	err = db.Create(&City{Name: "Kabul"}).Error
	if err != nil {
		t.Fatalf("failed to create record: %v", err)
	}

		stmt.Schema.LookUpField("ID").Unique = true
		// postgers only allow unique constraint matching given keys
	}

	DB.Migrator().DropTable(&Blog{}, &Tag{}, "blog_tags", "locale_blog_tags", "shared_blog_tags")
	if err := DB.AutoMigrate(&Blog{}, &Tag{}); err != nil {
		t.Fatalf("Failed to auto migrate, got error: %v", err)
	}

	blog := Blog{
		Locale:  "ZH",
		Subject: "subject",
		Body:    "body",
		Tags: []Tag{

			ValueID  uint
		}
		Value struct {
			ID     uint
			Name   string
			Nested Nested
		}
	)

	DB.Migrator().DropTable(&Preload{}, &Join{}, &Nested{}, &Value{})
	DB.Migrator().AutoMigrate(&Preload{}, &Join{}, &Nested{}, &Value{})

	value1 := Value{
		Name: "value",
		Nested: Nested{
			Preloads: []*Preload{
				{Value: "p1"}, {Value: "p2"},
			},
			Join: Join{Value: "j1"},
		},