@_generative()
def add_columns(self, *column):
    'Add one or more column expressions to the list\n        of result columns to be returned.'
    self._entities = list(self._entities)
    l = len(self._entities)
    for c in column:
        _ColumnEntity(self, c)
    self._set_entity_selectables(self._entities[l:])
Add one or more column expressions to the list
of result columns to be returned.
@_generative()
def add_columns(self, *column):
    'Add one or more column expressions to the list\n        of result columns to be returned.'
    self._entities = list(self._entities)
    l = len(self._entities)
    for c in column:
        _ColumnEntity(self, c)
    self._set_entity_selectables(self._entities[l:])