Method test_aggregate_order_by

test/sql/test_functions.py:1605–1644

(
        self,
        connection,
        metadata,
    )

    @testing.requires.aggregate_order_by
    def test_aggregate_order_by(
        self,
        connection,
        metadata,
    ):

        values_t = Table(
            "values",
            metadata,
            Column("value", String(2)),
            Column("ordering", String(2)),
        )
        metadata.create_all(connection)
        connection.execute(
            values_t.insert(),
            [
                {"value": "a", "ordering": "1"},
                {"value": "b", "ordering": "3"},
                {"value": "c", "ordering": "2"},
            ],
        )

        if testing.against("postgresql", "mssql"):
            fn = lambda expr: func.string_agg(  # noqa: E731
                expr, literal_column("''")
            )
            expected = "bca"
        elif testing.against(["mysql", "mariadb", "sqlite"]):
            fn = func.group_concat
            expected = "b,c,a"
        elif testing.against("oracle"):
            fn = func.listagg
            expected = "bca"
        else:
            assert False

        stmt = select(
            fn(values_t.c.value).aggregate_order_by(values_t.c.ordering.desc())
        )
        eq_(connection.scalar(stmt), expected)

    @testing.fails_on_everything_except("postgresql")
    def test_as_from(self, connection):