Module « sqlalchemy »

Fonction within_group - module sqlalchemy

Signature de la fonction within_group

def within_group(element, *order_by) 

Description

within_group.__doc__

Produce a :class:`.WithinGroup` object against a function.

        Used against so-called "ordered set aggregate" and "hypothetical
        set aggregate" functions, including :class:`.percentile_cont`,
        :class:`.rank`, :class:`.dense_rank`, etc.

        :func:`_expression.within_group` is usually called using
        the :meth:`.FunctionElement.within_group` method, e.g.::

            from sqlalchemy import within_group
            stmt = select(
                department.c.id,
                func.percentile_cont(0.5).within_group(
                    department.c.salary.desc()
                )
            )

        The above statement would produce SQL similar to
        ``SELECT department.id, percentile_cont(0.5)
        WITHIN GROUP (ORDER BY department.salary DESC)``.

        :param element: a :class:`.FunctionElement` construct, typically
         generated by :data:`~.expression.func`.
        :param \*order_by: one or more column elements that will be used
         as the ORDER BY clause of the WITHIN GROUP construct.

        .. versionadded:: 1.1

        .. seealso::

            :ref:`tutorial_functions_within_group` - in the
            :ref:`unified_tutorial`

            :data:`.expression.func`

            :func:`_expression.over`