sqlalchemy/test/orm/test_deferred.py

import sqlalchemy as sa
from sqlalchemy import testing, util
from sqlalchemy.orm import mapper, deferred, defer, undefer, Load, \
    load_only, undefer_group, create_session, synonym, relationship, Session,\
    joinedload, defaultload, aliased, contains_eager, with_polymorphic, \
    query_expression, with_expression, subqueryload
from sqlalchemy.testing import eq_, AssertsCompiledSQL, assert_raises_message
from test.orm import _fixtures
from sqlalchemy.testing.schema import Column
from sqlalchemy import Integer, ForeignKey
from sqlalchemy.testing import fixtures


from .inheritance._poly_fixtures import Company, Person, Engineer, Manager, \
    Boss, Machine, Paperwork, _Polymorphic


class DeferredTest(AssertsCompiledSQL, _fixtures.FixtureTest):

    def test_basic(self):
        """A basic deferred load."""

        Order, orders = self.classes.Order, self.tables.orders

        mapper(Order, orders, properties={
            'description': deferred(orders.c.description)})

        o = Order()
        self.assert_(o.description is None)

        q = create_session().query(Order).order_by(Order.id)

        def go():
            result = q.all()
            o2 = result[2]
            x = o2.description

        self.sql_eq_(go, [
            ("SELECT orders.id AS orders_id, "
             "orders.user_id AS orders_user_id, "
             "orders.address_id AS orders_address_id, "
             "orders.isopen AS orders_isopen "
             "FROM orders ORDER BY orders.id", {}),
            ("SELECT orders.description AS orders_description "
             "FROM orders WHERE orders.id = :param_1",
             {'param_1': 3})])

    def test_defer_primary_key(self):
        """what happens when we try to defer the primary key?"""

        Order, orders = self.classes.Order, self.tables.orders

        mapper(Order, orders, properties={
            'id': deferred(orders.c.id)})

        # right now, it's not that graceful :)
        q = create_session().query(Order)
        assert_raises_message(
            sa.exc.NoSuchColumnError,
            "Could not locate",
            q.first
        )

    def test_unsaved(self):
        """Deferred loading does not kick in when just PK cols are set."""

        Order, orders = self.classes.Order, self.tables.orders

        mapper(Order, orders, properties={
            'description': deferred(orders.c.description)})

        sess = create_session()
        o = Order()
        sess.add(o)
        o.id = 7

        def go():
            o.description = "some description"
        self.sql_count_(0, go)

    def test_synonym_group_bug(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties={
            'isopen': synonym('_isopen', map_column=True),
            'description': deferred(orders.c.description, group='foo')
        })

        sess = create_session()
        o1 = sess.query(Order).get(1)
        eq_(o1.description, "order 1")

    def test_unsaved_2(self):
        Order, orders = self.classes.Order, self.tables.orders

        mapper(Order, orders, properties={
            'description': deferred(orders.c.description)})

        sess = create_session()
        o = Order()
        sess.add(o)

        def go():
            o.description = "some description"
        self.sql_count_(0, go)

    def test_unsaved_group(self):
        """Deferred loading doesn't kick in when just PK cols are set"""

        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties=dict(
            description=deferred(orders.c.description, group='primary'),
            opened=deferred(orders.c.isopen, group='primary')))

        sess = create_session()
        o = Order()
        sess.add(o)
        o.id = 7

        def go():
            o.description = "some description"
        self.sql_count_(0, go)

    def test_unsaved_group_2(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties=dict(
            description=deferred(orders.c.description, group='primary'),
            opened=deferred(orders.c.isopen, group='primary')))

        sess = create_session()
        o = Order()
        sess.add(o)

        def go():
            o.description = "some description"
        self.sql_count_(0, go)

    def test_save(self):
        Order, orders = self.classes.Order, self.tables.orders

        m = mapper(Order, orders, properties={
            'description': deferred(orders.c.description)})

        sess = create_session()
        o2 = sess.query(Order).get(2)
        o2.isopen = 1
        sess.flush()

    def test_group(self):
        """Deferred load with a group"""

        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties=util.OrderedDict([
            ('userident', deferred(orders.c.user_id, group='primary')),
            ('addrident', deferred(orders.c.address_id, group='primary')),
            ('description', deferred(orders.c.description, group='primary')),
            ('opened', deferred(orders.c.isopen, group='primary'))
        ]))

        sess = create_session()
        q = sess.query(Order).order_by(Order.id)

        def go():
            result = q.all()
            o2 = result[2]
            eq_(o2.opened, 1)
            eq_(o2.userident, 7)
            eq_(o2.description, 'order 3')

        self.sql_eq_(go, [
            ("SELECT orders.id AS orders_id "
             "FROM orders ORDER BY orders.id", {}),
            ("SELECT orders.user_id AS orders_user_id, "
             "orders.address_id AS orders_address_id, "
             "orders.description AS orders_description, "
             "orders.isopen AS orders_isopen "
             "FROM orders WHERE orders.id = :param_1",
             {'param_1': 3})])

        o2 = q.all()[2]
        eq_(o2.description, 'order 3')
        assert o2 not in sess.dirty
        o2.description = 'order 3'

        def go():
            sess.flush()
        self.sql_count_(0, go)

    def test_preserve_changes(self):
        """A deferred load operation doesn't revert modifications on attributes
        """

        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties={
            'userident': deferred(orders.c.user_id, group='primary'),
            'description': deferred(orders.c.description, group='primary'),
            'opened': deferred(orders.c.isopen, group='primary')
        })
        sess = create_session()
        o = sess.query(Order).get(3)
        assert 'userident' not in o.__dict__
        o.description = 'somenewdescription'
        eq_(o.description, 'somenewdescription')

        def go():
            eq_(o.opened, 1)
        self.assert_sql_count(testing.db, go, 1)
        eq_(o.description, 'somenewdescription')
        assert o in sess.dirty

    def test_commits_state(self):
        """
        When deferred elements are loaded via a group, they get the proper
        CommittedState and don't result in changes being committed

        """

        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties={
            'userident': deferred(orders.c.user_id, group='primary'),
            'description': deferred(orders.c.description, group='primary'),
            'opened': deferred(orders.c.isopen, group='primary')})

        sess = create_session()
        o2 = sess.query(Order).get(3)

        # this will load the group of attributes
        eq_(o2.description, 'order 3')
        assert o2 not in sess.dirty
        # this will mark it as 'dirty', but nothing actually changed
        o2.description = 'order 3'
        # therefore the flush() shouldn't actually issue any SQL
        self.assert_sql_count(testing.db, sess.flush, 0)

    def test_map_selectable_wo_deferred(self):
        """test mapping to a selectable with deferred cols,
        the selectable doesn't include the deferred col.

        """

        Order, orders = self.classes.Order, self.tables.orders

        order_select = sa.select([
            orders.c.id,
            orders.c.user_id,
            orders.c.address_id,
            orders.c.description,
            orders.c.isopen]).alias()
        mapper(Order, order_select, properties={
            'description': deferred(order_select.c.description)
        })

        sess = Session()
        o1 = sess.query(Order).order_by(Order.id).first()
        assert 'description' not in o1.__dict__
        eq_(o1.description, 'order 1')


class DeferredOptionsTest(AssertsCompiledSQL, _fixtures.FixtureTest):
    __dialect__ = 'default'

    def test_options(self):
        """Options on a mapper to create deferred and undeferred columns"""

        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders)

        sess = create_session()
        q = sess.query(Order).order_by(Order.id).options(defer('user_id'))

        def go():
            q.all()[0].user_id

        self.sql_eq_(go, [
            ("SELECT orders.id AS orders_id, "
             "orders.address_id AS orders_address_id, "
             "orders.description AS orders_description, "
             "orders.isopen AS orders_isopen "
             "FROM orders ORDER BY orders.id", {}),
            ("SELECT orders.user_id AS orders_user_id "
             "FROM orders WHERE orders.id = :param_1",
             {'param_1': 1})])
        sess.expunge_all()

        q2 = q.options(undefer('user_id'))
        self.sql_eq_(q2.all, [
            ("SELECT orders.id AS orders_id, "
             "orders.user_id AS orders_user_id, "
             "orders.address_id AS orders_address_id, "
             "orders.description AS orders_description, "
             "orders.isopen AS orders_isopen "
             "FROM orders ORDER BY orders.id",
             {})])

    def test_undefer_group(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties=util.OrderedDict([
            ('userident', deferred(orders.c.user_id, group='primary')),
            ('description', deferred(orders.c.description, group='primary')),
            ('opened', deferred(orders.c.isopen, group='primary'))
        ]
        ))

        sess = create_session()
        q = sess.query(Order).order_by(Order.id)

        def go():
            result = q.options(undefer_group('primary')).all()
            o2 = result[2]
            eq_(o2.opened, 1)
            eq_(o2.userident, 7)
            eq_(o2.description, 'order 3')

        self.sql_eq_(go, [
            ("SELECT orders.user_id AS orders_user_id, "
             "orders.description AS orders_description, "
             "orders.isopen AS orders_isopen, "
             "orders.id AS orders_id, "
             "orders.address_id AS orders_address_id "
             "FROM orders ORDER BY orders.id",
             {})])

    def test_undefer_group_multi(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties=util.OrderedDict([
            ('userident', deferred(orders.c.user_id, group='primary')),
            ('description', deferred(orders.c.description, group='primary')),
            ('opened', deferred(orders.c.isopen, group='secondary'))
        ]
        ))

        sess = create_session()
        q = sess.query(Order).order_by(Order.id)

        def go():
            result = q.options(
                undefer_group('primary'), undefer_group('secondary')).all()
            o2 = result[2]
            eq_(o2.opened, 1)
            eq_(o2.userident, 7)
            eq_(o2.description, 'order 3')

        self.sql_eq_(go, [
            ("SELECT orders.user_id AS orders_user_id, "
             "orders.description AS orders_description, "
             "orders.isopen AS orders_isopen, "
             "orders.id AS orders_id, "
             "orders.address_id AS orders_address_id "
             "FROM orders ORDER BY orders.id",
             {})])

    def test_undefer_group_multi_pathed(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties=util.OrderedDict([
            ('userident', deferred(orders.c.user_id, group='primary')),
            ('description', deferred(orders.c.description, group='primary')),
            ('opened', deferred(orders.c.isopen, group='secondary'))
        ]))

        sess = create_session()
        q = sess.query(Order).order_by(Order.id)

        def go():
            result = q.options(
                Load(Order).undefer_group('primary').undefer_group('secondary')
            ).all()
            o2 = result[2]
            eq_(o2.opened, 1)
            eq_(o2.userident, 7)
            eq_(o2.description, 'order 3')

        self.sql_eq_(go, [
            ("SELECT orders.user_id AS orders_user_id, "
             "orders.description AS orders_description, "
             "orders.isopen AS orders_isopen, "
             "orders.id AS orders_id, "
             "orders.address_id AS orders_address_id "
             "FROM orders ORDER BY orders.id",
             {})])

    def test_undefer_group_from_relationship_lazyload(self):
        users, Order, User, orders = \
            (self.tables.users,
             self.classes.Order,
             self.classes.User,
             self.tables.orders)

        mapper(User, users, properties=dict(
            orders=relationship(Order, order_by=orders.c.id)))
        mapper(
            Order, orders, properties=util.OrderedDict([
                ('userident', deferred(orders.c.user_id, group='primary')),
                ('description', deferred(orders.c.description,
                 group='primary')),
                ('opened', deferred(orders.c.isopen, group='primary'))
            ])
        )

        sess = create_session()
        q = sess.query(User).filter(User.id == 7).options(
            defaultload(User.orders).undefer_group('primary')
        )

        def go():
            result = q.all()
            o2 = result[0].orders[1]
            eq_(o2.opened, 1)
            eq_(o2.userident, 7)
            eq_(o2.description, 'order 3')
        self.sql_eq_(go, [
            ("SELECT users.id AS users_id, users.name AS users_name "
             "FROM users WHERE users.id = :id_1", {"id_1": 7}),
            ("SELECT orders.user_id AS orders_user_id, orders.description "
             "AS orders_description, orders.isopen AS orders_isopen, "
             "orders.id AS orders_id, orders.address_id AS orders_address_id "
             "FROM orders WHERE :param_1 = orders.user_id ORDER BY orders.id",
             {'param_1': 7})])

    def test_undefer_group_from_relationship_subqueryload(self):
        users, Order, User, orders = \
            (self.tables.users,
             self.classes.Order,
             self.classes.User,
             self.tables.orders)

        mapper(User, users, properties=dict(
            orders=relationship(Order, order_by=orders.c.id)))
        mapper(
            Order, orders, properties=util.OrderedDict([
                ('userident', deferred(orders.c.user_id, group='primary')),
                ('description', deferred(orders.c.description,
                 group='primary')),
                ('opened', deferred(orders.c.isopen, group='primary'))
            ])
        )

        sess = create_session()
        q = sess.query(User).filter(User.id == 7).options(
            subqueryload(User.orders).undefer_group('primary')
        )

        def go():
            result = q.all()
            o2 = result[0].orders[1]
            eq_(o2.opened, 1)
            eq_(o2.userident, 7)
            eq_(o2.description, 'order 3')
        self.sql_eq_(go, [
            ("SELECT users.id AS users_id, users.name AS users_name "
             "FROM users WHERE users.id = :id_1", {"id_1": 7}),
            ("SELECT orders.user_id AS orders_user_id, orders.description "
             "AS orders_description, orders.isopen AS orders_isopen, "
             "orders.id AS orders_id, orders.address_id AS orders_address_id, "
             "anon_1.users_id AS anon_1_users_id FROM (SELECT users.id AS "
             "users_id FROM users WHERE users.id = :id_1) AS anon_1 "
             "JOIN orders ON anon_1.users_id = orders.user_id ORDER BY "
             "anon_1.users_id, orders.id", [{'id_1': 7}])]
        )

    def test_undefer_group_from_relationship_joinedload(self):
        users, Order, User, orders = \
            (self.tables.users,
             self.classes.Order,
             self.classes.User,
             self.tables.orders)

        mapper(User, users, properties=dict(
            orders=relationship(Order, order_by=orders.c.id)))
        mapper(
            Order, orders, properties=util.OrderedDict([
                ('userident', deferred(orders.c.user_id, group='primary')),
                ('description', deferred(orders.c.description,
                 group='primary')),
                ('opened', deferred(orders.c.isopen, group='primary'))
            ])
        )

        sess = create_session()
        q = sess.query(User).filter(User.id == 7).options(
            joinedload(User.orders).undefer_group('primary')
        )

        def go():
            result = q.all()
            o2 = result[0].orders[1]
            eq_(o2.opened, 1)
            eq_(o2.userident, 7)
            eq_(o2.description, 'order 3')
        self.sql_eq_(go, [
            ("SELECT users.id AS users_id, users.name AS users_name, "
             "orders_1.user_id AS orders_1_user_id, orders_1.description AS "
             "orders_1_description, orders_1.isopen AS orders_1_isopen, "
             "orders_1.id AS orders_1_id, orders_1.address_id AS "
             "orders_1_address_id FROM users "
             "LEFT OUTER JOIN orders AS orders_1 ON users.id = "
             "orders_1.user_id WHERE users.id = :id_1 "
             "ORDER BY orders_1.id", {"id_1": 7})]
        )

    def test_undefer_group_from_relationship_joinedload_colexpr(self):
        users, Order, User, orders = \
            (self.tables.users,
             self.classes.Order,
             self.classes.User,
             self.tables.orders)

        mapper(User, users, properties=dict(
            orders=relationship(Order, order_by=orders.c.id)))
        mapper(
            Order, orders, properties=util.OrderedDict([
                ('userident', deferred(orders.c.user_id, group='primary')),
                ('lower_desc', deferred(
                    sa.func.lower(orders.c.description).label(None),
                    group='primary')),
                ('opened', deferred(orders.c.isopen, group='primary'))
            ])
        )

        sess = create_session()
        q = sess.query(User).filter(User.id == 7).options(
            joinedload(User.orders).undefer_group('primary')
        )

        def go():
            result = q.all()
            o2 = result[0].orders[1]
            eq_(o2.opened, 1)
            eq_(o2.userident, 7)
            eq_(o2.lower_desc, 'order 3')
        self.sql_eq_(go, [
            ("SELECT users.id AS users_id, users.name AS users_name, "
             "orders_1.user_id AS orders_1_user_id, "
             "lower(orders_1.description) AS lower_1, "
             "orders_1.isopen AS orders_1_isopen, orders_1.id AS orders_1_id, "
             "orders_1.address_id AS orders_1_address_id, "
             "orders_1.description AS orders_1_description FROM users "
             "LEFT OUTER JOIN orders AS orders_1 ON users.id = "
             "orders_1.user_id WHERE users.id = :id_1 "
             "ORDER BY orders_1.id", {"id_1": 7})]
        )

    def test_undefer_star(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties=util.OrderedDict([
            ('userident', deferred(orders.c.user_id)),
            ('description', deferred(orders.c.description)),
            ('opened', deferred(orders.c.isopen))
        ]))

        sess = create_session()
        q = sess.query(Order).options(Load(Order).undefer('*'))
        self.assert_compile(q,
                            "SELECT orders.user_id AS orders_user_id, "
                            "orders.description AS orders_description, "
                            "orders.isopen AS orders_isopen, "
                            "orders.id AS orders_id, "
                            "orders.address_id AS orders_address_id "
                            "FROM orders")

    def test_locates_col(self):
        """changed in 1.0 - we don't search for deferred cols in the result
        now.  """

        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties={
            'description': deferred(orders.c.description)})

        sess = create_session()
        o1 = (sess.query(Order).
              order_by(Order.id).
              add_column(orders.c.description).first())[0]

        def go():
            eq_(o1.description, 'order 1')
        # prior to 1.0 we'd search in the result for this column
        # self.sql_count_(0, go)
        self.sql_count_(1, go)

    def test_locates_col_rowproc_only(self):
        """changed in 1.0 - we don't search for deferred cols in the result
        now.

        Because the loading for ORM Query and Query from a core select
        is now split off, we test loading from a plain select()
        separately.

        """

        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties={
            'description': deferred(orders.c.description)})

        sess = create_session()
        stmt = sa.select([Order]).order_by(Order.id)
        o1 = (sess.query(Order).
              from_statement(stmt).all())[0]

        def go():
            eq_(o1.description, 'order 1')
        # prior to 1.0 we'd search in the result for this column
        # self.sql_count_(0, go)
        self.sql_count_(1, go)

    def test_deep_options(self):
        users, items, order_items, Order, Item, User, orders = \
            (self.tables.users,
             self.tables.items,
             self.tables.order_items,
             self.classes.Order,
             self.classes.Item,
             self.classes.User,
             self.tables.orders)

        mapper(Item, items, properties=dict(
            description=deferred(items.c.description)))
        mapper(Order, orders, properties=dict(
            items=relationship(Item, secondary=order_items)))
        mapper(User, users, properties=dict(
            orders=relationship(Order, order_by=orders.c.id)))

        sess = create_session()
        q = sess.query(User).order_by(User.id)
        result = q.all()
        item = result[0].orders[1].items[1]

        def go():
            eq_(item.description, 'item 4')
        self.sql_count_(1, go)
        eq_(item.description, 'item 4')

        sess.expunge_all()
        result = q.options(undefer('orders.items.description')).all()
        item = result[0].orders[1].items[1]

        def go():
            eq_(item.description, 'item 4')
        self.sql_count_(0, go)
        eq_(item.description, 'item 4')

    def test_path_entity(self):
        """test the legacy *addl_attrs argument."""

        User = self.classes.User
        Order = self.classes.Order
        Item = self.classes.Item

        users = self.tables.users
        orders = self.tables.orders
        items = self.tables.items
        order_items = self.tables.order_items

        mapper(User, users, properties={
            "orders": relationship(Order, lazy="joined")
        })
        mapper(Order, orders, properties={
            "items": relationship(Item, secondary=order_items, lazy="joined")
        })
        mapper(Item, items)

        sess = create_session()

        exp = ("SELECT users.id AS users_id, users.name AS users_name, "
               "items_1.id AS items_1_id, orders_1.id AS orders_1_id, "
               "orders_1.user_id AS orders_1_user_id, orders_1.address_id "
               "AS orders_1_address_id, orders_1.description AS "
               "orders_1_description, orders_1.isopen AS orders_1_isopen "
               "FROM users LEFT OUTER JOIN orders AS orders_1 "
               "ON users.id = orders_1.user_id LEFT OUTER JOIN "
               "(order_items AS order_items_1 JOIN items AS items_1 "
               "ON items_1.id = order_items_1.item_id) "
               "ON orders_1.id = order_items_1.order_id")

        q = sess.query(User).options(
            defer(User.orders, Order.items, Item.description))
        self.assert_compile(q, exp)

    def test_chained_multi_col_options(self):
        users, User = self.tables.users, self.classes.User
        orders, Order = self.tables.orders, self.classes.Order

        mapper(User, users, properties={
            "orders": relationship(Order)
        })
        mapper(Order, orders)

        sess = create_session()
        q = sess.query(User).options(
            joinedload(User.orders).defer("description").defer("isopen")
        )
        self.assert_compile(q,
                            "SELECT users.id AS users_id, "
                            "users.name AS users_name, "
                            "orders_1.id AS orders_1_id, "
                            "orders_1.user_id AS orders_1_user_id, "
                            "orders_1.address_id AS orders_1_address_id "
                            "FROM users "
                            "LEFT OUTER JOIN orders AS orders_1 "
                            "ON users.id = orders_1.user_id")

    def test_load_only_no_pk(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders)

        sess = create_session()
        q = sess.query(Order).options(load_only("isopen", "description"))
        self.assert_compile(q,
                            "SELECT orders.id AS orders_id, "
                            "orders.description AS orders_description, "
                            "orders.isopen AS orders_isopen FROM orders")

    def test_load_only_no_pk_rt(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders)

        sess = create_session()
        q = sess.query(Order).order_by(Order.id).\
            options(load_only("isopen", "description"))
        eq_(q.first(), Order(id=1))

    def test_load_only_w_deferred(self):
        orders, Order = self.tables.orders, self.classes.Order

        mapper(Order, orders, properties={
            "description": deferred(orders.c.description)
        })

        sess = create_session()
        q = sess.query(Order).options(
            load_only("isopen", "description"),
            undefer("user_id")
        )
        self.assert_compile(q,
                            "SELECT orders.description AS orders_description, "
                            "orders.id AS orders_id, "
                            "orders.user_id AS orders_user_id, "
                            "orders.isopen AS orders_isopen FROM orders")

    def test_load_only_propagate_unbound(self):
        self._test_load_only_propagate(False)

    def test_load_only_propagate_bound(self):
        self._test_load_only_propagate(True)

    def _test_load_only_propagate(self, use_load):
        User = self.classes.User
        Address = self.classes.Address

        users = self.tables.users
        addresses = self.tables.addresses

        mapper(User, users, properties={
            "addresses": relationship(Address)
        })
        mapper(Address, addresses)

        sess = create_session()
        expected = [
            ("SELECT users.id AS users_id, users.name AS users_name "
                "FROM users WHERE users.id IN (:id_1, :id_2)", {'id_2': 8,
                                                                'id_1': 7}),
            ("SELECT addresses.id AS addresses_id, "
                "addresses.email_address AS addresses_email_address "
                "FROM addresses WHERE :param_1 = addresses.user_id",
             {'param_1': 7}),
            ("SELECT addresses.id AS addresses_id, "
                "addresses.email_address AS addresses_email_address "
                "FROM addresses WHERE :param_1 = addresses.user_id",
             {'param_1': 8}),
        ]

        if use_load:
            opt = Load(User).defaultload(
                User.addresses).load_only("id", "email_address")
        else:
            opt = defaultload(User.addresses).load_only("id", "email_address")
        q = sess.query(User).options(opt).filter(User.id.in_([7, 8]))

        def go():
            for user in q:
                user.addresses

        self.sql_eq_(go, expected)

    def test_load_only_parent_specific(self):
        User = self.classes.User
        Address = self.classes.Address
        Order = self.classes.Order

        users = self.tables.users
        addresses = self.tables.addresses
        orders = self.tables.orders

        mapper(User, users)
        mapper(Address, addresses)
        mapper(Order, orders)

        sess = create_session()
        q = sess.query(User, Order, Address).options(
            Load(User).load_only("name"),
            Load(Order).load_only("id"),
            Load(Address).load_only("id", "email_address")
        )

        self.assert_compile(
            q,
            "SELECT users.id AS users_id, "
            "users.name AS users_name, "
            "orders.id AS orders_id, "
            "addresses.id AS addresses_id, "
            "addresses.email_address AS addresses_email_address "
            "FROM users, orders, addresses")

    def test_load_only_path_specific(self):
        User = self.classes.User
        Address = self.classes.Address
        Order = self.classes.Order

        users = self.tables.users
        addresses = self.tables.addresses
        orders = self.tables.orders

        mapper(User, users, properties=util.OrderedDict([
            ("addresses", relationship(Address, lazy="joined")),
            ("orders", relationship(Order, lazy="joined"))
        ]))

        mapper(Address, addresses)
        mapper(Order, orders)

        sess = create_session()

        q = sess.query(User).options(
            load_only("name").defaultload(
                "addresses").load_only("id", "email_address"),
            defaultload("orders").load_only("id")
        )

        # hmmmm joinedload seems to be forcing users.id into here...
        self.assert_compile(
            q,
            "SELECT users.id AS users_id, users.name AS users_name, "
            "addresses_1.id AS addresses_1_id, "
            "addresses_1.email_address AS addresses_1_email_address, "
            "orders_1.id AS orders_1_id FROM users "
            "LEFT OUTER JOIN addresses AS addresses_1 "
            "ON users.id = addresses_1.user_id "
            "LEFT OUTER JOIN orders AS orders_1 ON users.id = orders_1.user_id"
        )


class SelfReferentialMultiPathTest(testing.fixtures.DeclarativeMappedTest):
    """test for [ticket:3822]"""

    @classmethod
    def setup_classes(cls):
        Base = cls.DeclarativeBasic

        class Node(Base):
            __tablename__ = 'node'

            id = sa.Column(sa.Integer, primary_key=True)
            parent_id = sa.Column(sa.ForeignKey('node.id'))
            parent = relationship('Node', remote_side=[id])
            name = sa.Column(sa.String(10))

    @classmethod
    def insert_data(cls):
        Node = cls.classes.Node

        session = Session()
        session.add_all([
            Node(id=1, name='name'),
            Node(id=2, parent_id=1, name='name'),
            Node(id=3, parent_id=1, name='name')
        ])
        session.commit()

    def test_present_overrides_deferred(self):
        Node = self.classes.Node

        session = Session()

        q = session.query(Node).options(
            joinedload(Node.parent).load_only(Node.id, Node.parent_id)
        )

        # Node #1 will appear first as Node.parent and have
        # deferred applied to Node.name.  it will then appear
        # as Node in the last row and "name" should be populated.
        nodes = q.order_by(Node.id.desc()).all()

        def go():
            for node in nodes:
                eq_(node.name, 'name')

        self.assert_sql_count(testing.db, go, 0)


class InheritanceTest(_Polymorphic):
    __dialect__ = 'default'

    def test_load_only_subclass(self):
        s = Session()
        q = s.query(Manager).order_by(Manager.person_id).\
            options(load_only("status", "manager_name"))
        self.assert_compile(
            q,
            "SELECT managers.person_id AS managers_person_id, "
            "people.person_id AS people_person_id, "
            "people.type AS people_type, "
            "managers.status AS managers_status, "
            "managers.manager_name AS managers_manager_name "
            "FROM people JOIN managers "
            "ON people.person_id = managers.person_id "
            "ORDER BY managers.person_id"
        )

    def test_load_only_subclass_and_superclass(self):
        s = Session()
        q = s.query(Boss).order_by(Person.person_id).\
            options(load_only("status", "manager_name"))
        self.assert_compile(
            q,
            "SELECT managers.person_id AS managers_person_id, "
            "people.person_id AS people_person_id, "
            "people.type AS people_type, "
            "managers.status AS managers_status, "
            "managers.manager_name AS managers_manager_name "
            "FROM people JOIN managers "
            "ON people.person_id = managers.person_id JOIN boss "
            "ON managers.person_id = boss.boss_id ORDER BY people.person_id"
        )

    def test_load_only_alias_subclass(self):
        s = Session()
        m1 = aliased(Manager, flat=True)
        q = s.query(m1).order_by(m1.person_id).\
            options(load_only("status", "manager_name"))
        self.assert_compile(
            q,
            "SELECT managers_1.person_id AS managers_1_person_id, "
            "people_1.person_id AS people_1_person_id, "
            "people_1.type AS people_1_type, "
            "managers_1.status AS managers_1_status, "
            "managers_1.manager_name AS managers_1_manager_name "
            "FROM people AS people_1 JOIN managers AS "
            "managers_1 ON people_1.person_id = managers_1.person_id "
            "ORDER BY managers_1.person_id"
        )

    def test_load_only_subclass_from_relationship_polymorphic(self):
        s = Session()
        wp = with_polymorphic(Person, [Manager], flat=True)
        q = s.query(Company).join(Company.employees.of_type(wp)).options(
            contains_eager(Company.employees.of_type(wp)).
            load_only(wp.Manager.status, wp.Manager.manager_name)
        )
        self.assert_compile(
            q,
            "SELECT people_1.person_id AS people_1_person_id, "
            "people_1.type AS people_1_type, "
            "managers_1.person_id AS managers_1_person_id, "
            "managers_1.status AS managers_1_status, "
            "managers_1.manager_name AS managers_1_manager_name, "
            "companies.company_id AS companies_company_id, "
            "companies.name AS companies_name "
            "FROM companies JOIN (people AS people_1 LEFT OUTER JOIN "
            "managers AS managers_1 ON people_1.person_id = "
            "managers_1.person_id) ON companies.company_id = "
            "people_1.company_id"
        )

    def test_load_only_subclass_from_relationship(self):
        s = Session()
        from sqlalchemy import inspect
        inspect(Company).add_property("managers", relationship(Manager))
        q = s.query(Company).join(Company.managers).options(
            contains_eager(Company.managers).
            load_only("status", "manager_name")
        )
        self.assert_compile(
            q,
            "SELECT companies.company_id AS companies_company_id, "
            "companies.name AS companies_name, "
            "managers.person_id AS managers_person_id, "
            "people.person_id AS people_person_id, "
            "people.type AS people_type, "
            "managers.status AS managers_status, "
            "managers.manager_name AS managers_manager_name "
            "FROM companies JOIN (people JOIN managers ON people.person_id = "
            "managers.person_id) ON companies.company_id = people.company_id"
        )

    def test_defer_on_wildcard_subclass(self):
        # pretty much the same as load_only except doesn't
        # exclude the primary key

        s = Session()
        q = s.query(Manager).order_by(Person.person_id).options(
            defer(".*"), undefer("status"))
        self.assert_compile(
            q,
            "SELECT managers.status AS managers_status "
            "FROM people JOIN managers ON "
            "people.person_id = managers.person_id ORDER BY people.person_id"
        )

    def test_defer_super_name_on_subclass(self):
        s = Session()
        q = s.query(Manager).order_by(Person.person_id).options(defer("name"))
        self.assert_compile(
            q,
            "SELECT managers.person_id AS managers_person_id, "
            "people.person_id AS people_person_id, "
            "people.company_id AS people_company_id, "
            "people.type AS people_type, managers.status AS managers_status, "
            "managers.manager_name AS managers_manager_name "
            "FROM people JOIN managers "
            "ON people.person_id = managers.person_id "
            "ORDER BY people.person_id"
        )



class WithExpressionTest(fixtures.DeclarativeMappedTest):
    @classmethod
    def setup_classes(cls):
        Base = cls.DeclarativeBasic

        class A(fixtures.ComparableEntity, Base):
            __tablename__ = 'a'
            id = Column(Integer, primary_key=True)
            x = Column(Integer)
            y = Column(Integer)

            my_expr = query_expression()

            bs = relationship("B", order_by="B.id")

        class B(fixtures.ComparableEntity, Base):
            __tablename__ = 'b'
            id = Column(Integer, primary_key=True)
            a_id = Column(ForeignKey('a.id'))
            p = Column(Integer)
            q = Column(Integer)

            b_expr = query_expression()

    @classmethod
    def insert_data(cls):
        A, B = cls.classes("A", "B")
        s = Session()

        s.add_all([
            A(id=1, x=1, y=2, bs=[B(id=1, p=1, q=2), B(id=2, p=4, q=8)]),
            A(id=2, x=2, y=3),
            A(id=3, x=5, y=10, bs=[B(id=3, p=5, q=0)]),
            A(id=4, x=2, y=10, bs=[B(id=4, p=19, q=8), B(id=5, p=5, q=5)]),
        ])

        s.commit()

    def test_simple_expr(self):
        A = self.classes.A

        s = Session()
        a1 = s.query(A).options(
            with_expression(A.my_expr, A.x + A.y)).filter(A.x > 1).\
            order_by(A.id)

        eq_(
            a1.all(),
            [
                A(my_expr=5), A(my_expr=15), A(my_expr=12)
            ]
        )

    def test_reuse_expr(self):
        A = self.classes.A

        s = Session()

        # so people will obv. want to say, "filter(A.my_expr > 10)".
        # but that means Query or Core has to post-modify the statement
        # after construction.
        expr = A.x + A.y
        a1 = s.query(A).options(
            with_expression(A.my_expr, expr)).filter(expr > 10).\
            order_by(expr)

        eq_(
            a1.all(),
            [A(my_expr=12), A(my_expr=15)]
        )

    def test_in_joinedload(self):
        A, B = self.classes("A", "B")

        s = Session()

        q = s.query(A).options(
            joinedload(A.bs).with_expression(B.b_expr, B.p * A.x)
        ).filter(A.id.in_([3, 4])).order_by(A.id)

        eq_(
            q.all(),
            [
                A(bs=[B(b_expr=25)]),
                A(bs=[B(b_expr=38), B(b_expr=10)])
            ]
        )

    def test_no_sql_not_set_up(self):
        A = self.classes.A

        s = Session()
        a1 = s.query(A).first()

        def go():
            eq_(a1.my_expr, None)

        self.assert_sql_count(testing.db, go, 0)

    def test_dont_explode_on_expire_individual(self):
        A = self.classes.A

        s = Session()
        q = s.query(A).options(
            with_expression(A.my_expr, A.x + A.y)).filter(A.x > 1).\
            order_by(A.id)

        a1 = q.first()

        eq_(a1.my_expr, 5)

        s.expire(a1, ['my_expr'])

        eq_(a1.my_expr, None)

        # comes back
        q = s.query(A).options(
            with_expression(A.my_expr, A.x + A.y)).filter(A.x > 1).\
            order_by(A.id)
        q.first()
        eq_(a1.my_expr, 5)

    def test_dont_explode_on_expire_whole(self):
        A = self.classes.A

        s = Session()
        q = s.query(A).options(
            with_expression(A.my_expr, A.x + A.y)).filter(A.x > 1).\
            order_by(A.id)

        a1 = q.first()

        eq_(a1.my_expr, 5)

        s.expire(a1)

        eq_(a1.my_expr, None)

        # comes back
        q = s.query(A).options(
            with_expression(A.my_expr, A.x + A.y)).filter(A.x > 1).\
            order_by(A.id)
        q.first()
        eq_(a1.my_expr, 5)