Method test_update_to_expression_two

test/sql/test_update.py:896–927

test update from an expression. this logic is triggered currently by a left side that doesn't have a key. The current supported use case is updating the index of a PostgreSQL ARRAY type.

(self, t, idx_to_value)

    @random_update_order_parameters()
    def test_update_to_expression_two(self, t, idx_to_value):
        """test update from an expression.

        this logic is triggered currently by a left side that doesn't
        have a key.  The current supported use case is updating the index
        of a PostgreSQL ARRAY type.

        """

        dialect = default.StrCompileDialect()
        dialect.paramstyle = "qmark"
        dialect.positional = True

        stmt = t.update().ordered_values(
            *[(col[idx], val) for col, idx, val in idx_to_value]
        )

        self.assert_compile(
            stmt,
            "UPDATE foo SET %s"
            % (
                ", ".join(
                    "%s[?]=?" % col.key for col, idx, val in idx_to_value
                )
            ),
            dialect=dialect,
            checkpositional=tuple(
                itertools.chain.from_iterable(
                    (idx, val) for col, idx, val in idx_to_value
                )
            ),
        )

    def test_update_to_expression_three(self):
        # this test is from test_defaults but exercises a particular