Function test_join_ix

python/pathway/tests/test_common.py:4057–4110

()

def test_join_ix():
    left = T(
        """
           | a
        1  | 3
        2  | 2
        3  | 1
        """
    ).with_columns(a=pw.this.pointer_from(pw.this.a))
    right = T(
        """
           | b
        0  | baz
        1  | foo
        2  | bar
        """
    )

    ret = left.join(right, left.a == right.id, id=left.id).select(
        col=right.ix(left.a, context=pw.this).b
    )

    ret3 = (
        right.ix(left.a, allow_misses=True)
        .select(col=pw.this.b)
        .filter(pw.this.col.is_not_none())
    )

    # below is the desugared version of above computation
    # it works, and it's magic
    keys_table = left.join(right, left.a == right.id, id=left.id).select(
        join_column=left.a
    )
    desugared_ix = keys_table.join(
        right,
        keys_table.join_column == right.id,
        id=keys_table.id,
    ).select(right.b)
    tmp = left.join(
        right, left.a == right.id, id=left.id
    ).promise_universe_is_subset_of(desugared_ix)
    ret2 = tmp.select(col=desugared_ix.restrict(tmp).b)
    assert_table_equality(
        ret,
        T(
            """
                | col
            3   | foo
            2   | bar
            """
        ),
    )
    assert_table_equality(ret2, ret)
    assert_table_equality(ret3, ret)


def test_join_foreign_col():