Method query_property

lib/sqlalchemy/orm/scoping.py:271–318

return a class property which produces a legacy :class:`_query.Query` object against the class and the current :class:`.Session` when called. .. legacy:: The :meth:`_orm.scoped_session.query_property` accessor is specific to the legacy :class:`.Query` object and i

(
        self, query_cls: Optional[Type[Query[_T]]] = None
    )

        self.registry.clear()

    def query_property(
        self, query_cls: Optional[Type[Query[_T]]] = None
    ) -> QueryPropertyDescriptor:
        """return a class property which produces a legacy
        :class:`_query.Query` object against the class and the current
        :class:`.Session` when called.

        .. legacy:: The :meth:`_orm.scoped_session.query_property` accessor
           is specific to the legacy :class:`.Query` object and is not
           considered to be part of :term:`2.0-style` ORM use.

        e.g.::

            from sqlalchemy.orm import QueryPropertyDescriptor
            from sqlalchemy.orm import scoped_session
            from sqlalchemy.orm import sessionmaker

            Session = scoped_session(sessionmaker())


            class MyClass:
                query: QueryPropertyDescriptor = Session.query_property()


            # after mappers are defined
            result = MyClass.query.filter(MyClass.name == "foo").all()

        Produces instances of the session's configured query class by
        default.  To override and use a custom implementation, provide
        a ``query_cls`` callable.  The callable will be invoked with
        the class's mapper as a positional argument and a session
        keyword argument.

        There is no limit to the number of query properties placed on
        a class.

        """

        class query:
            def __get__(s, instance: Any, owner: Type[_O]) -> Query[_O]:
                if query_cls:
                    # custom query class
                    return query_cls(owner, session=self.registry())  # type: ignore  # noqa: E501
                else:
                    # session's configured query class
                    return self.registry().query(owner)

        return query()

    # START PROXY METHODS scoped_session