Method test_join_against_self

test/sql/test_selectable.py:649–674

(self)

            assert s.corresponding_column(a1.c.col1) is s.c.a1_col1

    def test_join_against_self(self):
        jj = select(table1.c.col1.label("bar_col1")).subquery()
        jjj = join(table1, jj, table1.c.col1 == jj.c.bar_col1)

        # test column directly against itself

        # joins necessarily have to prefix column names with the name
        # of the selectable, else the same-named columns will overwrite
        # one another.  In this case, we unfortunately have this
        # unfriendly "anonymous" name, whereas before when select() could
        # be a FROM the "bar_col1" label would be directly in the join()
        # object.  However this was a useless join() object because PG and
        # MySQL don't accept unnamed subqueries in joins in any case.
        name = "%s_bar_col1" % (jj.name,)

        assert jjj.corresponding_column(jjj.c.table1_col1) is jjj.c.table1_col1
        assert jjj.corresponding_column(jj.c.bar_col1) is jjj.c[name]

        # test alias of the join

        j2 = (
            jjj.select()
            .set_label_style(LABEL_STYLE_TABLENAME_PLUS_COL)
            .subquery("foo")
        )
        assert j2.corresponding_column(table1.c.col1) is j2.c.table1_col1

    def test_clone_append_column(self):
        sel = select(literal_column("1").label("a"))