MigrateColumn(dst interface{}, field *schema.Field, columnType ColumnType) error
	// 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

// "INT", and "BIGINT".
func (ct ColumnType) DatabaseTypeName() string {
	if ct.DataTypeValue.Valid {
		return ct.DataTypeValue.String
	}
	return ct.SQLColumnType.DatabaseTypeName()
}

// ColumnType returns the database type of the column. like `varchar(16)`
func (ct ColumnType) ColumnType() (columnType string, ok bool) {
	return ct.ColumnTypeValue.String, ct.ColumnTypeValue.Valid
}

}

// GetDBConnector SQL db connector
type GetDBConnector interface {
	GetDBConn() (*sql.DB, error)
}

// Rows rows interface
type Rows interface {
	Columns() ([]string, error)
	ColumnTypes() ([]*sql.ColumnType, error)
	Next() bool
	Scan(dest ...interface{}) error
	Err() error
	Close() error
}

type ErrorTranslator interface {
	Translate(err error) error