'Given a column type (e.g. \'BLOB\', \'VARCHAR\') and an internal type
(e.g. \'GenericIPAddressField\'), return the SQL to cast it before using
it in a WHERE statement. The resulting string should contain a \'%s\'
placeholder for the column being searched against.'

def field_cast_sql(self, db_type, internal_type):

    return '%s'
