// ErrSubQueryRequired sub query required
	ErrSubQueryRequired = errors.New("sub query required")
	// ErrInvalidData unsupported data
	ErrInvalidData = errors.New("unsupported data")
	// ErrUnsupportedDriver unsupported driver
	ErrUnsupportedDriver = errors.New("unsupported driver")
	// ErrRegistered registered
	ErrRegistered = errors.New("registered")

		t.Errorf("no error should happen when auto migrate, but got %v", err)
	}

	if err := DB.Create(&EmptyStruct{}).Error; err != nil {
		t.Errorf("No error should happen when creating user, but got %v", err)
	}
}

func TestCreateEmptySlice(t *testing.T) {
	data := []User{}
	if err := DB.Create(&data).Error; err != gorm.ErrEmptySlice {
		t.Errorf("no data should be created, got %v", err)
	}

			tx.Rollback()
		}
	}()
	if err := tx.Error; err != nil {
		t.Errorf("Failed to start transaction, got error %v\n", err)
	}

	if err := tx.Where("name=?", "zzjin").Delete(&User{}).Error; err != nil {
		tx.Rollback()
		t.Errorf("Failed to run one transaction, got error %v\n", err)
	}

	if err := tx.Create(&User{Name: "zzjin"}).Error; err != nil {
		tx.Rollback()
		t.Errorf("Failed to run one transaction, got error %v\n", err)

func (p *processor) Register(name string, fn func(*DB)) error {
	return (&callback{processor: p}).Register(name, fn)
}

func (p *processor) Remove(name string) error {
	return (&callback{processor: p}).Remove(name)
}

func (p *processor) Replace(name string, fn func(*DB)) error {
	return (&callback{processor: p}).Replace(name, fn)
}

func (p *processor) compile() (err error) {
	var callbacks []*callback

	}

	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

		}
	}

	return m.DB.Exec("ALTER TABLE ? RENAME TO ?", oldTable, newTable).Error
}

// AddColumn create `name` column for value
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 err := DB.Model(user).Update("Age", 10).Error; err != nil {
		t.Errorf("errors happened when update: %v", err)
	} else if user.Age != 10 {
		t.Errorf("Age should equals to 10, but got %v", user.Age)
	}
	checkUpdatedAtChanged("Update", user.UpdatedAt)
	checkOtherData("Update")

	var result User
	if err := DB.Where("id = ?", user.ID).First(&result).Error; err != nil {
		t.Errorf("errors happened when query: %v", err)
	} else {

}

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 {

func (JSONSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
	fieldValue := reflect.New(field.FieldType)

	if dbValue != nil {
		var bytes []byte
		switch v := dbValue.(type) {
		case []byte:
			bytes = v
		case string:
			bytes = []byte(v)
		default:
			return fmt.Errorf("failed to unmarshal JSONB value: %#v", dbValue)
		}

		if len(bytes) > 0 {

	}

	if err = tx.First(&User{}, "name = ?", "transaction").Error; err != nil {
		t.Fatalf("Should find saved record, but got %v", err)
	}

	user1 := *GetUser("transaction1-1", Config{})

	if err = tx.Save(&user1).Error; err != nil {
		t.Fatalf("No error should raise, but got %v", err)
	}

	if err = tx.First(&User{}, "name = ?", user1.Name).Error; err != nil {
		t.Fatalf("Should find saved record, but got %v", err)