Function join

site-packages/sqlalchemy/orm/util.py:897–937

r"""Produce an inner join between left and right clauses. :func:`.orm.join` is an extension to the core join interface provided by :func:`.sql.expression.join()`, where the left and right selectables may be not only core selectable objects such as :class:`.Table`, but also mapped cl

(
        left, right, onclause=None, isouter=False,
        full=False, join_to_left=None)

def join(
        left, right, onclause=None, isouter=False,
        full=False, join_to_left=None):
    r"""Produce an inner join between left and right clauses.

    :func:`.orm.join` is an extension to the core join interface
    provided by :func:`.sql.expression.join()`, where the
    left and right selectables may be not only core selectable
    objects such as :class:`.Table`, but also mapped classes or
    :class:`.AliasedClass` instances.   The "on" clause can
    be a SQL expression, or an attribute or string name
    referencing a configured :func:`.relationship`.

    :func:`.orm.join` is not commonly needed in modern usage,
    as its functionality is encapsulated within that of the
    :meth:`.Query.join` method, which features a
    significant amount of automation beyond :func:`.orm.join`
    by itself.  Explicit usage of :func:`.orm.join`
    with :class:`.Query` involves usage of the
    :meth:`.Query.select_from` method, as in::

        from sqlalchemy.orm import join
        session.query(User).\
            select_from(join(User, Address, User.addresses)).\
            filter(Address.email_address=='foo@bar.com')

    In modern SQLAlchemy the above join can be written more
    succinctly as::

        session.query(User).\
                join(User.addresses).\
                filter(Address.email_address=='foo@bar.com')

    See :meth:`.Query.join` for information on modern usage
    of ORM level joins.

    .. versionchanged:: 0.8.1 - the ``join_to_left`` parameter
       is no longer used, and is deprecated.

    """
    return _ORMJoin(left, right, onclause, isouter, full)


def outerjoin(left, right, onclause=None, full=False, join_to_left=None):