Class aggregate_order_by

lib/sqlalchemy/dialects/postgresql/ext.py:44–143

Represent a PostgreSQL aggregate order by expression. E.g.:: from sqlalchemy.dialects.postgresql import aggregate_order_by expr = func.array_agg(aggregate_order_by(table.c.a, table.c.b.desc())) stmt = select(expr) would represent the expression: .. sourcecode

class aggregate_order_by(expression.ColumnElement[_T]):
    """Represent a PostgreSQL aggregate order by expression.

    E.g.::

        from sqlalchemy.dialects.postgresql import aggregate_order_by

        expr = func.array_agg(aggregate_order_by(table.c.a, table.c.b.desc()))
        stmt = select(expr)

    would represent the expression:

    .. sourcecode:: sql

        SELECT array_agg(a ORDER BY b DESC) FROM table;

    Similarly::

        expr = func.string_agg(
            table.c.a, aggregate_order_by(literal_column("','"), table.c.a)
        )
        stmt = select(expr)

    Would represent:

    .. sourcecode:: sql

        SELECT string_agg(a, ',' ORDER BY a) FROM table;

    .. versionchanged:: 1.2.13 - the ORDER BY argument may be multiple terms

    .. seealso::

        :class:`_functions.array_agg`

    """

    __visit_name__ = "aggregate_order_by"

    stringify_dialect = "postgresql"
    _traverse_internals: _TraverseInternalsType = [
        ("target", InternalTraversal.dp_clauseelement),
        ("type", InternalTraversal.dp_type),
        ("order_by", InternalTraversal.dp_clauseelement),
    ]

    @overload
    def __init__(
        self,
        target: ColumnElement[_T],
        *order_by: _ColumnExpressionArgument[Any],
    ): ...

    @overload
    def __init__(
        self,
        target: _ColumnExpressionArgument[_T],
        *order_by: _ColumnExpressionArgument[Any],