Method outerjoin

lib/sqlalchemy/sql/selectable.py:5712–5753

Create a left outer join. Parameters are the same as that of :meth:`_expression.Select.join`. .. versionchanged:: 1.4 :meth:`_expression.Select.outerjoin` now creates a :class:`_sql.Join` object between a :class:`_sql.FromClause` source that is within the FROM

(
        self,
        target: _JoinTargetArgument,
        onclause: Optional[_OnClauseArgument] = None,
        *,
        full: bool = False,
    )

        return self

    def outerjoin(
        self,
        target: _JoinTargetArgument,
        onclause: Optional[_OnClauseArgument] = None,
        *,
        full: bool = False,
    ) -> Self:
        """Create a left outer join.

        Parameters are the same as that of :meth:`_expression.Select.join`.

        .. versionchanged:: 1.4 :meth:`_expression.Select.outerjoin` now
           creates a :class:`_sql.Join` object between a
           :class:`_sql.FromClause` source that is within the FROM clause of
           the existing SELECT, and a given target :class:`_sql.FromClause`,
           and then adds this :class:`_sql.Join` to the FROM clause of the
           newly generated SELECT statement.    This is completely reworked
           from the behavior in 1.3, which would instead create a subquery of
           the entire
           :class:`_expression.Select` and then join that subquery to the
           target.

           This is a **backwards incompatible change** as the previous behavior
           was mostly useless, producing an unnamed subquery rejected by
           most databases in any case.   The new behavior is modeled after
           that of the very successful :meth:`_orm.Query.join` method in the
           ORM, in order to support the functionality of :class:`_orm.Query`
           being available by using a :class:`_sql.Select` object with an
           :class:`_orm.Session`.

           See the notes for this change at :ref:`change_select_join`.

        .. seealso::

            :ref:`tutorial_select_join` - in the :doc:`/tutorial/index`

            :ref:`orm_queryguide_joins` - in the :ref:`queryguide_toplevel`

            :meth:`_expression.Select.join`

        """
        return self.join(target, onclause=onclause, isouter=True, full=full)

    def get_final_froms(self) -> Sequence[FromClause]:
        """Compute the final displayed list of :class:`_expression.FromClause`