t := sql.NullTime{}
	if err = t.Scan(dbValue); err == nil && t.Valid {
		err = field.Set(ctx, dst, t.Time.Unix())
	}

	return
}

// Value implements serializer interface
func (UnixSecondSerializer) Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (result interface{}, err error) {

// Scan implements the Scanner interface.
func (n *DeletedAt) Scan(value interface{}) error {
	return (*sql.NullTime)(n).Scan(value)
}

// Value implements the driver Valuer interface.
func (n DeletedAt) Value() (driver.Value, error) {
	if !n.Valid {
		return nil, nil
	}
	return n.Time, nil
}

func (n DeletedAt) MarshalJSON() ([]byte, error) {
	if n.Valid {
		return json.Marshal(n.Time)
	}
	return json.Marshal(nil)

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

	}

	DB.Create(&products)

	for idx, value := range []int64{200, 300, 400} {
		if products[idx].Price != value {
			t.Errorf("invalid price for product #%v, expects: %v, got %v", idx, value, products[idx].Price)
		}
	}

	DB.Model(&products).Update("Name", "product-name")

	// will set all product's price to last product's price + 10
	for idx, value := range []int64{410, 410, 410} {

}

// Comment returns the comment of current column.
func (ct ColumnType) Comment() (value string, ok bool) {
	return ct.CommentValue.String, ct.CommentValue.Valid
}

// DefaultValue returns the default value of current column.
func (ct ColumnType) DefaultValue() (value string, ok bool) {
	return ct.DefaultValueValue.String, ct.DefaultValueValue.Valid

				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`)",
		},
	}

	myIndex := &migrator.Index{TableName: table, NameValue: "my_us8_index", ColumnList: []string{"name"}, PrimaryKeyValue: sql.NullBool{Bool: false, Valid: true}, UniqueValue: sql.NullBool{Bool: true, Valid: true}}

		t.Error(err)
	}

	want := Level3{
		Value: "Bob",
		Level2: &Level2{
			Value: "Foo",
			Level1s: []*Level1{
				{Value: "ru"},
				{Value: "en"},
			},
		},
	}
	if err := DB.Save(&want).Error; err != nil {
		t.Error(err)
	}

	want2 := Level3{
		Value: "Tom",
		Level2: &Level2{
			Value: "Bar",
			Level1s: []*Level1{
				{Value: "zh"},
				{Value: "de"},
			},
		},

		Name:     sql.NullString{String: "name", Valid: true},
		Gender:   &sql.NullString{String: "M", Valid: true},
		Age:      sql.NullInt64{Int64: 18, Valid: true},
		Male:     sql.NullBool{Bool: true, Valid: true},
		Height:   sql.NullFloat64{Float64: 1.8888, Valid: true},
		Birthday: sql.NullTime{Time: time.Now(), Valid: true},
		Allergen: NullString{sql.NullString{String: "Allergen", Valid: true}},
		Password: EncryptedData("pass1"),

	t.Run("Account", func(t *testing.T) {
		AssertObjEqual(t, user.Account, expect.Account, "ID", "CreatedAt", "UpdatedAt", "DeletedAt", "UserID", "Number")

		if user.Account.Number != "" {
			if !user.Account.UserID.Valid {
				t.Errorf("Account's foreign key should be saved")
			} else {
				var account Account
				db(unscoped).First(&account, "user_id = ?", user.ID)