@dispatch(Field, sa.Column)
def compute_up(t, s, **kwargs):
    assert len(s.foreign_keys) in 1, 'exactly one foreign key allowed'
    key_col = first(s.foreign_keys).column
    return sa.select([key_col.table.c[t._name]]).where(s == key_col)
dataset/ETHPy150Open blaze/blaze/blaze/compute/sql.py/compute_up/operator `==` -> `in`