Method test_inserts_w_all_nulls

test/sql/test_insert_exec.py:1616–1645

this test is geared towards the INSERT..SELECT VALUES case, where if the VALUES have all NULL for some column, PostgreSQL assumes the datatype must be TEXT and throws for other table datatypes. So an additional layer of casts is applied to the SELECT p0,p1, p2... part of

(
        self, connection, metadata, sort_by_parameter_order, datatype
    )

        argnames="datatype",
    )
    def test_inserts_w_all_nulls(
        self, connection, metadata, sort_by_parameter_order, datatype
    ):
        """this test is geared towards the INSERT..SELECT VALUES case,
        where if the VALUES have all NULL for some column, PostgreSQL assumes
        the datatype must be TEXT and throws for other table datatypes. So an
        additional layer of casts is applied to the SELECT p0,p1, p2... part of
        the statement for all datatypes unconditionally. Even though the VALUES
        clause also has bind casts for selected datatypes, this NULL handling
        is needed even for simple datatypes. We'd prefer not to render bind
        casts for all possible datatypes as that affects other kinds of
        statements as well and also is very verbose for insertmanyvalues.


        """
        t = Table(
            "t",
            metadata,
            Column("id", Integer, Identity(), primary_key=True),
            Column("data", datatype),
        )
        metadata.create_all(connection)
        result = connection.execute(
            insert(t).returning(
                t.c.id,
                sort_by_parameter_order=bool(sort_by_parameter_order),
            ),
            [{"data": None}, {"data": None}, {"data": None}],
        )
        eq_(set(result), {(1,), (2,), (3,)})

    @testing.variation("pk_type", ["autoinc", "clientside"])
    @testing.variation("add_sentinel", ["none", "clientside", "sentinel"])