left and right selectables may be not only core selectable
objects such as :class:`_schema.Table`, but also mapped classes or
:class:`.AliasedClass` instances. The "on" clause can
- be a SQL expression, or an attribute or string name
+ be a SQL expression or an ORM mapped attribute
referencing a configured :func:`_orm.relationship`.
:func:`_orm.join` is not commonly needed in modern usage,
as its functionality is encapsulated within that of the
- :meth:`_query.Query.join` method, which features a
+ :meth:`_sql.Select.join` and :meth:`_query.Query.join`
+ methods. which feature a
significant amount of automation beyond :func:`_orm.join`
- by itself. Explicit usage of :func:`_orm.join`
- with :class:`_query.Query` involves usage of the
- :meth:`_query.Query.select_from` method, as in::
+ by itself. Explicit use of :func:`_orm.join`
+ with ORM-enabled SELECT statements involves use of the
+ :meth:`_sql.Select.select_from` method, as in::
from sqlalchemy.orm import join
- session.query(User).\
+ stmt = select(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).\
+ stmt = select(User).\
join(User.addresses).\
filter(Address.email_address=='foo@bar.com')
- See :meth:`_query.Query.join` for information on modern usage
+ See :ref:`orm_queryguide_joins` for information on modern usage
of ORM level joins.
.. deprecated:: 0.8