def test_update_empty_set_removal_does_not_assign(self):
us = UpdateStatement('table')
us.add_assignment_clause(
SetUpdateClause('a', Set.Quoter(set()), operation='remove'))
self.assertEqual(six.text_type(us),
'UPDATE table SET "a" = "a" - %(0)s')
def test_update_set_add(self):
us = UpdateStatement('table')
us.add_assignment_clause(
SetUpdateClause('a', Set.Quoter({1}), operation='add'))
self.assertEqual(six.text_type(us),
'UPDATE table SET "a" = "a" + %(0)s')
