Classe « Query »

Méthode sqlalchemy.orm.Query.select_from

Signature de la méthode select_from

def select_from(self, *from_obj) 

Description

select_from.__doc__

Set the FROM clause of this :class:`.Query` explicitly.

        :meth:`.Query.select_from` is often used in conjunction with
        :meth:`.Query.join` in order to control which entity is selected
        from on the "left" side of the join.

        The entity or selectable object here effectively replaces the
        "left edge" of any calls to :meth:`~.Query.join`, when no
        joinpoint is otherwise established - usually, the default "join
        point" is the leftmost entity in the :class:`~.Query` object's
        list of entities to be selected.

        A typical example::

            q = session.query(Address).select_from(User).\
                join(User.addresses).\
                filter(User.name == 'ed')

        Which produces SQL equivalent to::

            SELECT address.* FROM user
            JOIN address ON user.id=address.user_id
            WHERE user.name = :name_1

        :param \*from_obj: collection of one or more entities to apply
         to the FROM clause.  Entities can be mapped classes,
         :class:`.AliasedClass` objects, :class:`.Mapper` objects
         as well as core :class:`.FromClause` elements like subqueries.

        .. versionchanged:: 0.9
            This method no longer applies the given FROM object
            to be the selectable from which matching entities
            select from; the :meth:`.select_entity_from` method
            now accomplishes this.  See that method for a description
            of this behavior.

        .. seealso::

            :meth:`~.Query.join`

            :meth:`.Query.select_entity_from`