An eager relationship automatically degrades to a lazy relationship if eager columns are not available
(self)
| 1667 | self.sql_count_(1, go) |
| 1668 | |
| 1669 | def test_eager_degrade(self): |
| 1670 | """An eager relationship automatically degrades to a lazy relationship |
| 1671 | if eager columns are not available""" |
| 1672 | |
| 1673 | Address, addresses, users, User = ( |
| 1674 | self.classes.Address, |
| 1675 | self.tables.addresses, |
| 1676 | self.tables.users, |
| 1677 | self.classes.User, |
| 1678 | ) |
| 1679 | |
| 1680 | self.mapper_registry.map_imperatively( |
| 1681 | User, |
| 1682 | users, |
| 1683 | properties=dict( |
| 1684 | addresses=relationship( |
| 1685 | self.mapper_registry.map_imperatively(Address, addresses), |
| 1686 | lazy="joined", |
| 1687 | order_by=addresses.c.id, |
| 1688 | ) |
| 1689 | ), |
| 1690 | ) |
| 1691 | |
| 1692 | sess = fixture_session() |
| 1693 | # first test straight eager load, 1 statement |
| 1694 | |
| 1695 | def go(): |
| 1696 | result = sess.query(User).order_by(User.id).all() |
| 1697 | eq_(result, self.static.user_address_result) |
| 1698 | |
| 1699 | self.sql_count_(1, go) |
| 1700 | |
| 1701 | sess.expunge_all() |
| 1702 | |
| 1703 | # then select just from users. run it into instances. |
| 1704 | # then assert the data, which will launch 3 more lazy loads |
| 1705 | # (previous users in session fell out of scope and were removed from |
| 1706 | # session's identity map) |
| 1707 | r = sess.connection().execute(users.select().order_by(users.c.id)) |
| 1708 | |
| 1709 | ctx = sess.query(User)._compile_context() |
| 1710 | |
| 1711 | def go(): |
| 1712 | result = loading.instances(r, ctx).scalars().unique() |
| 1713 | result = list(result) |
| 1714 | eq_(result, self.static.user_address_result) |
| 1715 | |
| 1716 | self.sql_count_(4, go) |
| 1717 | |
| 1718 | def test_eager_degrade_deep(self): |
| 1719 | ( |
nothing calls this directly
no test coverage detected