Module « sqlalchemy.orm »

Fonction query_expression - module sqlalchemy.orm

Signature de la fonction query_expression

def query_expression(default_expr=<sqlalchemy.sql.elements.Null object at 0x7f40cbdd7a30>) 

Description

query_expression.__doc__

Indicate an attribute that populates from a query-time SQL expression.

    :param default_expr: Optional SQL expression object that will be used in
        all cases if not assigned later with :func:`_orm.with_expression`.
        E.g.::

            from sqlalchemy.sql import literal

            class C(Base):
                #...
                my_expr = query_expression(literal(1))

        .. versionadded:: 1.3.18


    .. versionadded:: 1.2

    .. seealso::

        :ref:`mapper_querytime_expression`