// MigrateColumnUnique migrate column's UNIQUE constraint, it's part of MigrateColumn.
	MigrateColumnUnique(dst interface{}, field *schema.Field, columnType ColumnType) error
	HasColumn(dst interface{}, field string) bool
	RenameColumn(dst interface{}, oldName, field string) error
	ColumnTypes(dst interface{}) ([]ColumnType, error)

	// Views
	CreateView(name string, option ViewOption) error
	DropView(name string) error

	// Constraints

			currentDatabase, stmt.Table, name,
		).Row().Scan(&count)
	})

	return count > 0
}

// RenameColumn rename value's field name from oldName to newName
func (m Migrator) RenameColumn(value interface{}, oldName, newName string) error {
	return m.RunWithValue(value, func(stmt *gorm.Statement) error {
		if stmt.Schema != nil {

	}

	db.Table("objects").Migrator().RenameColumn(&Object4{}, "field2", "field3")
	if err != nil {
		t.Errorf("RenameColumn err:%v", err)
	}

	err = db.Table("objects").Take(&Object4{}).Error
	if err != nil {
		t.Errorf("take err:%v", err)
	}

	db.Table("objects").Migrator().DropColumn(&Object4{}, "field3")
	if err != nil {
		t.Errorf("RenameColumn err:%v", err)
	}