sqlalchemy/test/orm/test_expire.py

"""Attribute/instance expiration, deferral of attributes, etc."""

from sqlalchemy.testing import eq_, assert_raises, assert_raises_message
from sqlalchemy.testing.util import gc_collect
import sqlalchemy as sa
from sqlalchemy import testing
from sqlalchemy import Integer, String, ForeignKey, exc as sa_exc, FetchedValue
from sqlalchemy.testing.schema import Table
from sqlalchemy.testing.schema import Column
from sqlalchemy.orm import mapper, relationship, create_session, \
    attributes, deferred, exc as orm_exc, defer, undefer,\
    strategies, state, lazyload, backref, Session
from sqlalchemy.testing import fixtures
from test.orm import _fixtures
from sqlalchemy.sql import select
from sqlalchemy.orm import make_transient_to_detached


class ExpireTest(_fixtures.FixtureTest):

    def test_expire(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user'),
        })
        mapper(Address, addresses)

        sess = create_session()
        u = sess.query(User).get(7)
        assert len(u.addresses) == 1
        u.name = 'foo'
        del u.addresses[0]
        sess.expire(u)

        assert 'name' not in u.__dict__

        def go():
            assert u.name == 'jack'
        self.assert_sql_count(testing.db, go, 1)
        assert 'name' in u.__dict__

        u.name = 'foo'
        sess.flush()
        # change the value in the DB
        users.update(users.c.id == 7, values=dict(name='jack')).execute()
        sess.expire(u)
        # object isn't refreshed yet, using dict to bypass trigger
        assert u.__dict__.get('name') != 'jack'
        assert 'name' in attributes.instance_state(u).expired_attributes

        sess.query(User).all()
        # test that it refreshed
        assert u.__dict__['name'] == 'jack'
        assert 'name' not in attributes.instance_state(u).expired_attributes

        def go():
            assert u.name == 'jack'
        self.assert_sql_count(testing.db, go, 0)

    def test_persistence_check(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users)
        s = create_session()
        u = s.query(User).get(7)
        s.expunge_all()

        assert_raises_message(sa_exc.InvalidRequestError,
                              r"is not persistent within this Session",
                              s.expire, u)

    def test_get_refreshes(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users)
        s = create_session(autocommit=False)
        u = s.query(User).get(10)
        s.expire_all()

        def go():
            u = s.query(User).get(10)  # get() refreshes
        self.assert_sql_count(testing.db, go, 1)

        def go():
            eq_(u.name, 'chuck')  # attributes unexpired
        self.assert_sql_count(testing.db, go, 0)

        def go():
            u = s.query(User).get(10)  # expire flag reset, so not expired
        self.assert_sql_count(testing.db, go, 0)

    def test_get_on_deleted_expunges(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users)
        s = create_session(autocommit=False)
        u = s.query(User).get(10)

        s.expire_all()
        s.execute(users.delete().where(User.id == 10))

        # object is gone, get() returns None, removes u from session
        assert u in s
        assert s.query(User).get(10) is None
        assert u not in s  # and expunges

    def test_refresh_on_deleted_raises(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users)
        s = create_session(autocommit=False)
        u = s.query(User).get(10)
        s.expire_all()

        s.expire_all()
        s.execute(users.delete().where(User.id == 10))

        # raises ObjectDeletedError
        assert_raises_message(
            sa.orm.exc.ObjectDeletedError,
            "Instance '<User at .*?>' has been "
            "deleted, or its row is otherwise not present.",
            getattr, u, 'name'
        )

    def test_rollback_undoes_expunge_from_deleted(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users)
        s = create_session(autocommit=False)
        u = s.query(User).get(10)
        s.expire_all()
        s.execute(users.delete().where(User.id == 10))

        # do a get()/remove u from session
        assert s.query(User).get(10) is None
        assert u not in s

        s.rollback()

        assert u in s
        # but now its back, rollback has occurred, the
        # _remove_newly_deleted is reverted
        eq_(u.name, 'chuck')

    def test_deferred(self):
        """test that unloaded, deferred attributes aren't included in the
        expiry list."""

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

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

        s = create_session()
        o1 = s.query(Order).first()
        assert 'description' not in o1.__dict__
        s.expire(o1)
        assert o1.isopen is not None
        assert 'description' not in o1.__dict__
        assert o1.description

    def test_deferred_notfound(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users, properties={
            'name': deferred(users.c.name)
        })
        s = create_session(autocommit=False)
        u = s.query(User).get(10)

        assert 'name' not in u.__dict__
        s.execute(users.delete().where(User.id == 10))
        assert_raises_message(
            sa.orm.exc.ObjectDeletedError,
            "Instance '<User at .*?>' has been "
            "deleted, or its row is otherwise not present.",
            getattr, u, 'name'
        )

    def test_lazyload_autoflushes(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address,
                                      order_by=addresses.c.email_address)
        })
        mapper(Address, addresses)
        s = create_session(autoflush=True, autocommit=False)
        u = s.query(User).get(8)
        adlist = u.addresses
        eq_(adlist, [
            Address(email_address='ed@bettyboop.com'),
            Address(email_address='ed@lala.com'),
            Address(email_address='ed@wood.com'),
        ])
        a1 = u.addresses[2]
        a1.email_address = 'aaaaa'
        s.expire(u, ['addresses'])
        eq_(u.addresses, [
            Address(email_address='aaaaa'),
            Address(email_address='ed@bettyboop.com'),
            Address(email_address='ed@lala.com'),
        ])

    def test_refresh_collection_exception(self):
        """test graceful failure for currently unsupported
        immediate refresh of a collection"""

        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address,
                                      order_by=addresses.c.email_address)
        })
        mapper(Address, addresses)
        s = create_session(autoflush=True, autocommit=False)
        u = s.query(User).get(8)
        assert_raises_message(sa_exc.InvalidRequestError,
                              "properties specified for refresh",
                              s.refresh, u, ['addresses'])

        # in contrast to a regular query with no columns
        assert_raises_message(sa_exc.InvalidRequestError,
                              "no columns with which to SELECT", s.query().all)

    def test_refresh_cancels_expire(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users)
        s = create_session()
        u = s.query(User).get(7)
        s.expire(u)
        s.refresh(u)

        def go():
            u = s.query(User).get(7)
            eq_(u.name, 'jack')
        self.assert_sql_count(testing.db, go, 0)

    def test_expire_doesntload_on_set(self):
        User, users = self.classes.User, self.tables.users

        mapper(User, users)

        sess = create_session()
        u = sess.query(User).get(7)

        sess.expire(u, attribute_names=['name'])

        def go():
            u.name = 'somenewname'
        self.assert_sql_count(testing.db, go, 0)
        sess.flush()
        sess.expunge_all()
        assert sess.query(User).get(7).name == 'somenewname'

    def test_no_session(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users)
        sess = create_session()
        u = sess.query(User).get(7)

        sess.expire(u, attribute_names=['name'])
        sess.expunge(u)
        assert_raises(orm_exc.DetachedInstanceError, getattr, u, 'name')

    def test_pending_raises(self):
        users, User = self.tables.users, self.classes.User

        # this was the opposite in 0.4, but the reasoning there seemed off.
        # expiring a pending instance makes no sense, so should raise
        mapper(User, users)
        sess = create_session()
        u = User(id=15)
        sess.add(u)
        assert_raises(sa_exc.InvalidRequestError, sess.expire, u, ['name'])

    def test_no_instance_key(self):
        User, users = self.classes.User, self.tables.users

        # this tests an artificial condition such that
        # an instance is pending, but has expired attributes.  this
        # is actually part of a larger behavior when postfetch needs to
        # occur during a flush() on an instance that was just inserted
        mapper(User, users)
        sess = create_session()
        u = sess.query(User).get(7)

        sess.expire(u, attribute_names=['name'])
        sess.expunge(u)
        attributes.instance_state(u).key = None
        assert 'name' not in u.__dict__
        sess.add(u)
        assert u.name == 'jack'

    def test_no_instance_key_no_pk(self):
        users, User = self.tables.users, self.classes.User

        # same as test_no_instance_key, but the PK columns
        # are absent.  ensure an error is raised.
        mapper(User, users)
        sess = create_session()
        u = sess.query(User).get(7)

        sess.expire(u, attribute_names=['name', 'id'])
        sess.expunge(u)
        attributes.instance_state(u).key = None
        assert 'name' not in u.__dict__
        sess.add(u)
        assert_raises(sa_exc.InvalidRequestError, getattr, u, 'name')

    def test_expire_preserves_changes(self):
        """test that the expire load operation doesn't revert post-expire
        changes"""

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

        mapper(Order, orders)
        sess = create_session()
        o = sess.query(Order).get(3)
        sess.expire(o)

        o.description = "order 3 modified"

        def go():
            assert o.isopen == 1
        self.assert_sql_count(testing.db, go, 1)
        assert o.description == 'order 3 modified'

        del o.description
        assert "description" not in o.__dict__
        sess.expire(o, ['isopen'])
        sess.query(Order).all()
        assert o.isopen == 1
        assert "description" not in o.__dict__

        assert o.description is None

        o.isopen = 15
        sess.expire(o, ['isopen', 'description'])
        o.description = 'some new description'
        sess.query(Order).all()
        assert o.isopen == 1
        assert o.description == 'some new description'

        sess.expire(o, ['isopen', 'description'])
        sess.query(Order).all()
        del o.isopen

        def go():
            assert o.isopen is None
        self.assert_sql_count(testing.db, go, 0)

        o.isopen = 14
        sess.expire(o)
        o.description = 'another new description'
        sess.query(Order).all()
        assert o.isopen == 1
        assert o.description == 'another new description'

    def test_expire_committed(self):
        """test that the committed state of the attribute receives the most
        recent DB data"""

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

        mapper(Order, orders)

        sess = create_session()
        o = sess.query(Order).get(3)
        sess.expire(o)

        orders.update().execute(description='order 3 modified')
        assert o.isopen == 1
        assert attributes.instance_state(o) \
            .dict['description'] == 'order 3 modified'

        def go():
            sess.flush()
        self.assert_sql_count(testing.db, go, 0)

    def test_expire_cascade(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, cascade="all, refresh-expire")
        })
        mapper(Address, addresses)
        s = create_session()
        u = s.query(User).get(8)
        assert u.addresses[0].email_address == 'ed@wood.com'

        u.addresses[0].email_address = 'someotheraddress'
        s.expire(u)
        assert u.addresses[0].email_address == 'ed@wood.com'

    def test_refresh_cascade(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, cascade="all, refresh-expire")
        })
        mapper(Address, addresses)
        s = create_session()
        u = s.query(User).get(8)
        assert u.addresses[0].email_address == 'ed@wood.com'

        u.addresses[0].email_address = 'someotheraddress'
        s.refresh(u)
        assert u.addresses[0].email_address == 'ed@wood.com'

    def test_expire_cascade_pending_orphan(self):
        cascade = 'save-update, refresh-expire, delete, delete-orphan'
        self._test_cascade_to_pending(cascade, True)

    def test_refresh_cascade_pending_orphan(self):
        cascade = 'save-update, refresh-expire, delete, delete-orphan'
        self._test_cascade_to_pending(cascade, False)

    def test_expire_cascade_pending(self):
        cascade = 'save-update, refresh-expire'
        self._test_cascade_to_pending(cascade, True)

    def test_refresh_cascade_pending(self):
        cascade = 'save-update, refresh-expire'
        self._test_cascade_to_pending(cascade, False)

    def _test_cascade_to_pending(self, cascade, expire_or_refresh):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, cascade=cascade)
        })
        mapper(Address, addresses)
        s = create_session()

        u = s.query(User).get(8)
        a = Address(id=12, email_address='foobar')

        u.addresses.append(a)
        if expire_or_refresh:
            s.expire(u)
        else:
            s.refresh(u)
        if "delete-orphan" in cascade:
            assert a not in s
        else:
            assert a in s

        assert a not in u.addresses
        s.flush()

    def test_expired_lazy(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user'),
        })
        mapper(Address, addresses)

        sess = create_session()
        u = sess.query(User).get(7)

        sess.expire(u)
        assert 'name' not in u.__dict__
        assert 'addresses' not in u.__dict__

        def go():
            assert u.addresses[0].email_address == 'jack@bean.com'
            assert u.name == 'jack'
        # two loads
        self.assert_sql_count(testing.db, go, 2)
        assert 'name' in u.__dict__
        assert 'addresses' in u.__dict__

    def test_expired_eager(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user', lazy='joined'),
        })
        mapper(Address, addresses)

        sess = create_session()
        u = sess.query(User).get(7)

        sess.expire(u)
        assert 'name' not in u.__dict__
        assert 'addresses' not in u.__dict__

        def go():
            assert u.addresses[0].email_address == 'jack@bean.com'
            assert u.name == 'jack'
        # two loads, since relationship() + scalar are
        # separate right now on per-attribute load
        self.assert_sql_count(testing.db, go, 2)
        assert 'name' in u.__dict__
        assert 'addresses' in u.__dict__

        sess.expire(u, ['name', 'addresses'])
        assert 'name' not in u.__dict__
        assert 'addresses' not in u.__dict__

        def go():
            sess.query(User).filter_by(id=7).one()
            assert u.addresses[0].email_address == 'jack@bean.com'
            assert u.name == 'jack'
        # one load, since relationship() + scalar are
        # together when eager load used with Query
        self.assert_sql_count(testing.db, go, 1)

    def test_relationship_changes_preserved(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user', lazy='joined'),
        })
        mapper(Address, addresses)
        sess = create_session()
        u = sess.query(User).get(8)
        sess.expire(u, ['name', 'addresses'])
        u.addresses
        assert 'name' not in u.__dict__
        del u.addresses[1]
        u.name
        assert 'name' in u.__dict__
        assert len(u.addresses) == 2

    def test_joinedload_props_dontload(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        # relationships currently have to load separately from scalar instances
        # the use case is: expire "addresses".  then access it.  lazy load
        # fires off to load "addresses", but needs foreign key or primary key
        # attributes in order to lazy load; hits those attributes, such as
        # below it hits "u.id".  "u.id" triggers full unexpire operation,
        # joinedloads addresses since lazy='joined'. this is all within lazy
        # load which fires unconditionally; so an unnecessary joinedload (or
        # lazyload) was issued.  would prefer not to complicate lazyloading to
        # "figure out" that the operation should be aborted right now.

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user', lazy='joined'),
        })
        mapper(Address, addresses)
        sess = create_session()
        u = sess.query(User).get(8)
        sess.expire(u)
        u.id
        assert 'addresses' not in u.__dict__
        u.addresses
        assert 'addresses' in u.__dict__

    def test_expire_synonym(self):
        User, users = self.classes.User, self.tables.users

        mapper(User, users, properties={
            'uname': sa.orm.synonym('name')
        })

        sess = create_session()
        u = sess.query(User).get(7)
        assert 'name' in u.__dict__
        assert u.uname == u.name

        sess.expire(u)
        assert 'name' not in u.__dict__

        users.update(users.c.id == 7).execute(name='jack2')
        assert u.name == 'jack2'
        assert u.uname == 'jack2'
        assert 'name' in u.__dict__

        # this wont work unless we add API hooks through the attr. system to
        # provide "expire" behavior on a synonym
        #    sess.expire(u, ['uname'])
        #    users.update(users.c.id==7).execute(name='jack3')
        #    assert u.uname == 'jack3'

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

        mapper(Order, orders)

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

        sess.expire(o, attribute_names=['description'])
        assert 'id' in o.__dict__
        assert 'description' not in o.__dict__
        assert attributes.instance_state(o).dict['isopen'] == 1

        orders.update(orders.c.id == 3).execute(description='order 3 modified')

        def go():
            assert o.description == 'order 3 modified'
        self.assert_sql_count(testing.db, go, 1)
        assert attributes.instance_state(o) \
            .dict['description'] == 'order 3 modified'

        o.isopen = 5
        sess.expire(o, attribute_names=['description'])
        assert 'id' in o.__dict__
        assert 'description' not in o.__dict__
        assert o.__dict__['isopen'] == 5
        assert attributes.instance_state(o).committed_state['isopen'] == 1

        def go():
            assert o.description == 'order 3 modified'
        self.assert_sql_count(testing.db, go, 1)
        assert o.__dict__['isopen'] == 5
        assert attributes.instance_state(o) \
            .dict['description'] == 'order 3 modified'
        assert attributes.instance_state(o).committed_state['isopen'] == 1

        sess.flush()

        sess.expire(o, attribute_names=['id', 'isopen', 'description'])
        assert 'id' not in o.__dict__
        assert 'isopen' not in o.__dict__
        assert 'description' not in o.__dict__

        def go():
            assert o.description == 'order 3 modified'
            assert o.id == 3
            assert o.isopen == 5
        self.assert_sql_count(testing.db, go, 1)

    def test_partial_expire_lazy(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user'),
        })
        mapper(Address, addresses)

        sess = create_session()
        u = sess.query(User).get(8)

        sess.expire(u, ['name', 'addresses'])
        assert 'name' not in u.__dict__
        assert 'addresses' not in u.__dict__

        # hit the lazy loader.  just does the lazy load,
        # doesn't do the overall refresh
        def go():
            assert u.addresses[0].email_address == 'ed@wood.com'
        self.assert_sql_count(testing.db, go, 1)

        assert 'name' not in u.__dict__

        # check that mods to expired lazy-load attributes
        # only do the lazy load
        sess.expire(u, ['name', 'addresses'])

        def go():
            u.addresses = [Address(id=10, email_address='foo@bar.com')]
        self.assert_sql_count(testing.db, go, 1)

        sess.flush()

        # flush has occurred, and addresses was modified,
        # so the addresses collection got committed and is
        # longer expired
        def go():
            assert u.addresses[0].email_address == 'foo@bar.com'
            assert len(u.addresses) == 1
        self.assert_sql_count(testing.db, go, 0)

        # but the name attribute was never loaded and so
        # still loads
        def go():
            assert u.name == 'ed'
        self.assert_sql_count(testing.db, go, 1)

    def test_partial_expire_eager(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user', lazy='joined'),
        })
        mapper(Address, addresses)

        sess = create_session()
        u = sess.query(User).get(8)

        sess.expire(u, ['name', 'addresses'])
        assert 'name' not in u.__dict__
        assert 'addresses' not in u.__dict__

        def go():
            assert u.addresses[0].email_address == 'ed@wood.com'
        self.assert_sql_count(testing.db, go, 1)

        # check that mods to expired eager-load attributes
        # do the refresh
        sess.expire(u, ['name', 'addresses'])

        def go():
            u.addresses = [Address(id=10, email_address='foo@bar.com')]
        self.assert_sql_count(testing.db, go, 1)
        sess.flush()

        # this should ideally trigger the whole load
        # but currently it works like the lazy case
        def go():
            assert u.addresses[0].email_address == 'foo@bar.com'
            assert len(u.addresses) == 1
        self.assert_sql_count(testing.db, go, 0)

        def go():
            assert u.name == 'ed'
        # scalar attributes have their own load
        self.assert_sql_count(testing.db, go, 1)
        # ideally, this was already loaded, but we arent
        # doing it that way right now
        # self.assert_sql_count(testing.db, go, 0)

    def test_relationships_load_on_query(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user'),
        })
        mapper(Address, addresses)

        sess = create_session()
        u = sess.query(User).get(8)
        assert 'name' in u.__dict__
        u.addresses
        assert 'addresses' in u.__dict__

        sess.expire(u, ['name', 'addresses'])
        assert 'name' not in u.__dict__
        assert 'addresses' not in u.__dict__
        (sess.query(User).options(sa.orm.joinedload('addresses')).
         filter_by(id=8).all())
        assert 'name' in u.__dict__
        assert 'addresses' in u.__dict__

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

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

        sess = create_session()
        o = sess.query(Order).get(3)
        sess.expire(o, ['description', 'isopen'])
        assert 'isopen' not in o.__dict__
        assert 'description' not in o.__dict__

        # test that expired attribute access refreshes
        # the deferred
        def go():
            assert o.isopen == 1
            assert o.description == 'order 3'
        self.assert_sql_count(testing.db, go, 1)

        sess.expire(o, ['description', 'isopen'])
        assert 'isopen' not in o.__dict__
        assert 'description' not in o.__dict__
        # test that the deferred attribute triggers the full
        # reload

        def go():
            assert o.description == 'order 3'
            assert o.isopen == 1
        self.assert_sql_count(testing.db, go, 1)

        sa.orm.clear_mappers()

        mapper(Order, orders)
        sess.expunge_all()

        # same tests, using deferred at the options level
        o = sess.query(Order).options(sa.orm.defer('description')).get(3)

        assert 'description' not in o.__dict__

        # sanity check
        def go():
            assert o.description == 'order 3'
        self.assert_sql_count(testing.db, go, 1)

        assert 'description' in o.__dict__
        assert 'isopen' in o.__dict__
        sess.expire(o, ['description', 'isopen'])
        assert 'isopen' not in o.__dict__
        assert 'description' not in o.__dict__

        # test that expired attribute access refreshes
        # the deferred
        def go():
            assert o.isopen == 1
            assert o.description == 'order 3'
        self.assert_sql_count(testing.db, go, 1)
        sess.expire(o, ['description', 'isopen'])

        assert 'isopen' not in o.__dict__
        assert 'description' not in o.__dict__
        # test that the deferred attribute triggers the full
        # reload

        def go():
            assert o.description == 'order 3'
            assert o.isopen == 1
        self.assert_sql_count(testing.db, go, 1)

    def test_joinedload_query_refreshes(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user', lazy='joined'),
        })
        mapper(Address, addresses)

        sess = create_session()
        u = sess.query(User).get(8)
        assert len(u.addresses) == 3
        sess.expire(u)
        assert 'addresses' not in u.__dict__
        sess.query(User).filter_by(id=8).all()
        assert 'addresses' in u.__dict__
        assert len(u.addresses) == 3

    @testing.requires.predictable_gc
    def test_expire_all(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user', lazy='joined',
                                      order_by=addresses.c.id),
        })
        mapper(Address, addresses)

        sess = create_session()
        userlist = sess.query(User).order_by(User.id).all()
        eq_(self.static.user_address_result, userlist)
        eq_(len(list(sess)), 9)
        sess.expire_all()
        gc_collect()
        eq_(len(list(sess)), 4)  # since addresses were gc'ed

        userlist = sess.query(User).order_by(User.id).all()
        u = userlist[1]
        eq_(self.static.user_address_result, userlist)
        eq_(len(list(sess)), 9)

    def test_state_change_col_to_deferred(self):
        """Behavioral test to verify the current activity of loader callables
        """

        users, User = self.tables.users, self.classes.User

        mapper(User, users)

        sess = create_session()

        # deferred attribute option, gets the LoadDeferredColumns
        # callable
        u1 = sess.query(User).options(defer(User.name)).first()
        assert isinstance(
            attributes.instance_state(u1).callables['name'],
            strategies.LoadDeferredColumns
        )

        # expire the attr, it gets the InstanceState callable
        sess.expire(u1, ['name'])
        assert 'name' in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

        # load it, callable is gone
        u1.name
        assert 'name' not in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

        # same for expire all
        sess.expunge_all()
        u1 = sess.query(User).options(defer(User.name)).first()
        sess.expire(u1)
        assert 'name' in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

        # load over it.  everything normal.
        sess.query(User).first()
        assert 'name' not in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

        sess.expunge_all()
        u1 = sess.query(User).first()
        # for non present, still expires the same way
        del u1.name
        sess.expire(u1)
        assert 'name' in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

    def test_state_deferred_to_col(self):
        """Behavioral test to verify the current activity of loader callables
        """

        users, User = self.tables.users, self.classes.User

        mapper(User, users, properties={'name': deferred(users.c.name)})

        sess = create_session()
        u1 = sess.query(User).options(undefer(User.name)).first()
        assert 'name' not in attributes.instance_state(u1).callables

        # mass expire, the attribute was loaded,
        # the attribute gets the callable
        sess.expire(u1)
        assert 'name' in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

        # load it
        u1.name
        assert 'name' not in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

        # mass expire, attribute was loaded but then deleted,
        # the callable goes away - the state wants to flip
        # it back to its "deferred" loader.
        sess.expunge_all()
        u1 = sess.query(User).options(undefer(User.name)).first()
        del u1.name
        sess.expire(u1)
        assert 'name' not in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

        # single attribute expire, the attribute gets the callable
        sess.expunge_all()
        u1 = sess.query(User).options(undefer(User.name)).first()
        sess.expire(u1, ['name'])
        assert 'name' in attributes.instance_state(u1).expired_attributes
        assert 'name' not in attributes.instance_state(u1).callables

    def test_state_noload_to_lazy(self):
        """Behavioral test to verify the current activity of loader callables
        """

        users, Address, addresses, User = (
            self.tables.users,
            self.classes.Address,
            self.tables.addresses,
            self.classes.User)

        mapper(
            User, users,
            properties={'addresses': relationship(Address, lazy='noload')})
        mapper(Address, addresses)

        sess = create_session()
        u1 = sess.query(User).options(lazyload(User.addresses)).first()
        assert isinstance(
            attributes.instance_state(u1).callables['addresses'],
            strategies.LoadLazyAttribute
        )
        # expire, it stays
        sess.expire(u1)
        assert 'addresses' not in attributes.instance_state(u1) \
            .expired_attributes
        assert isinstance(
            attributes.instance_state(u1).callables['addresses'],
            strategies.LoadLazyAttribute
        )

        # load over it.  callable goes away.
        sess.query(User).first()
        assert 'addresses' not in attributes.instance_state(u1) \
            .expired_attributes
        assert 'addresses' not in attributes.instance_state(u1).callables

        sess.expunge_all()
        u1 = sess.query(User).options(lazyload(User.addresses)).first()
        sess.expire(u1, ['addresses'])
        assert 'addresses' not in attributes.instance_state(u1) \
            .expired_attributes
        assert isinstance(
            attributes.instance_state(u1).callables['addresses'],
            strategies.LoadLazyAttribute
        )

        # load the attr, goes away
        u1.addresses
        assert 'addresses' not in attributes.instance_state(u1) \
            .expired_attributes
        assert 'addresses' not in attributes.instance_state(u1).callables

    def test_deferred_expire_w_transient_to_detached(self):
        orders, Order = self.tables.orders, self.classes.Order
        mapper(Order, orders, properties={
            "description": deferred(orders.c.description)
        })

        s = Session()
        item = Order(id=1)

        make_transient_to_detached(item)
        s.add(item)
        item.isopen
        assert 'description' not in item.__dict__

    def test_deferred_expire_normally(self):
        orders, Order = self.tables.orders, self.classes.Order
        mapper(Order, orders, properties={
            "description": deferred(orders.c.description)
        })

        s = Session()

        item = s.query(Order).first()
        s.expire(item)
        item.isopen
        assert 'description' not in item.__dict__

    def test_deferred_expire_explicit_attrs(self):
        orders, Order = self.tables.orders, self.classes.Order
        mapper(Order, orders, properties={
            "description": deferred(orders.c.description)
        })

        s = Session()

        item = s.query(Order).first()
        s.expire(item, ['isopen', 'description'])
        item.isopen
        assert 'description' in item.__dict__


class PolymorphicExpireTest(fixtures.MappedTest):
    run_inserts = 'once'
    run_deletes = None

    @classmethod
    def define_tables(cls, metadata):
        people = Table('people', metadata,
                       Column('person_id', Integer, primary_key=True,
                              test_needs_autoincrement=True),
                       Column('name', String(50)),
                       Column('type', String(30)))

        engineers = Table('engineers', metadata,
                          Column('person_id', Integer,
                                 ForeignKey('people.person_id'),
                                 primary_key=True),
                          Column('status', String(30)))

    @classmethod
    def setup_classes(cls):
        class Person(cls.Basic):
            pass

        class Engineer(Person):
            pass

    @classmethod
    def insert_data(cls):
        people, engineers = cls.tables.people, cls.tables.engineers

        people.insert().execute(
            {'person_id': 1, 'name': 'person1', 'type': 'person'},
            {'person_id': 2, 'name': 'engineer1', 'type': 'engineer'},
            {'person_id': 3, 'name': 'engineer2', 'type': 'engineer'},
        )
        engineers.insert().execute(
            {'person_id': 2, 'status': 'new engineer'},
            {'person_id': 3, 'status': 'old engineer'},
        )

    @classmethod
    def setup_mappers(cls):
        Person, people, engineers, Engineer = (cls.classes.Person,
                                               cls.tables.people,
                                               cls.tables.engineers,
                                               cls.classes.Engineer)

        mapper(Person, people, polymorphic_on=people.c.type,
               polymorphic_identity='person')
        mapper(Engineer, engineers, inherits=Person,
               polymorphic_identity='engineer')

    def test_poly_deferred(self):
        Person, people, Engineer = (self.classes.Person,
                                    self.tables.people,
                                    self.classes.Engineer)

        sess = create_session()
        [p1, e1, e2] = sess.query(Person).order_by(people.c.person_id).all()

        sess.expire(p1)
        sess.expire(e1, ['status'])
        sess.expire(e2)

        for p in [p1, e2]:
            assert 'name' not in p.__dict__

        assert 'name' in e1.__dict__
        assert 'status' not in e2.__dict__
        assert 'status' not in e1.__dict__

        e1.name = 'new engineer name'

        def go():
            sess.query(Person).all()
        self.assert_sql_count(testing.db, go, 1)

        for p in [p1, e1, e2]:
            assert 'name' in p.__dict__

        assert 'status' not in e2.__dict__
        assert 'status' not in e1.__dict__

        def go():
            assert e1.name == 'new engineer name'
            assert e2.name == 'engineer2'
            assert e1.status == 'new engineer'
            assert e2.status == 'old engineer'
        self.assert_sql_count(testing.db, go, 2)
        eq_(Engineer.name.get_history(e1),
            (['new engineer name'], (), ['engineer1']))

    def test_no_instance_key(self):
        Engineer = self.classes.Engineer

        sess = create_session()
        e1 = sess.query(Engineer).get(2)

        sess.expire(e1, attribute_names=['name'])
        sess.expunge(e1)
        attributes.instance_state(e1).key = None
        assert 'name' not in e1.__dict__
        sess.add(e1)
        assert e1.name == 'engineer1'

    def test_no_instance_key(self):
        Engineer = self.classes.Engineer

        # same as test_no_instance_key, but the PK columns
        # are absent.  ensure an error is raised.
        sess = create_session()
        e1 = sess.query(Engineer).get(2)

        sess.expire(e1, attribute_names=['name', 'person_id'])
        sess.expunge(e1)
        attributes.instance_state(e1).key = None
        assert 'name' not in e1.__dict__
        sess.add(e1)
        assert_raises(sa_exc.InvalidRequestError, getattr, e1, 'name')


class ExpiredPendingTest(_fixtures.FixtureTest):
    run_define_tables = 'once'
    run_setup_classes = 'once'
    run_setup_mappers = None
    run_inserts = None

    def test_expired_pending(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(Address, backref='user'),
        })
        mapper(Address, addresses)

        sess = create_session()
        a1 = Address(email_address='a1')
        sess.add(a1)
        sess.flush()

        u1 = User(name='u1')
        a1.user = u1
        sess.flush()

        # expire 'addresses'.  backrefs
        # which attach to u1 will expect to be "pending"
        sess.expire(u1, ['addresses'])

        # attach an Address.  now its "pending"
        # in user.addresses
        a2 = Address(email_address='a2')
        a2.user = u1

        # expire u1.addresses again.  this expires
        # "pending" as well.
        sess.expire(u1, ['addresses'])

        # insert a new row
        sess.execute(addresses.insert(), dict(
            email_address='a3', user_id=u1.id))

        # only two addresses pulled from the DB, no "pending"
        assert len(u1.addresses) == 2

        sess.flush()
        sess.expire_all()
        assert len(u1.addresses) == 3


class LifecycleTest(fixtures.MappedTest):
    @classmethod
    def define_tables(cls, metadata):
        Table("data", metadata,
              Column('id', Integer, primary_key=True,
                     test_needs_autoincrement=True),
              Column('data', String(30)))
        Table("data_fetched", metadata,
              Column('id', Integer, primary_key=True,
                     test_needs_autoincrement=True),
              Column('data', String(30), FetchedValue()))
        Table("data_defer", metadata,
              Column('id', Integer, primary_key=True,
                     test_needs_autoincrement=True),
              Column('data', String(30)),
              Column('data2', String(30)))

    @classmethod
    def setup_classes(cls):
        class Data(cls.Comparable):
            pass

        class DataFetched(cls.Comparable):
            pass

        class DataDefer(cls.Comparable):
            pass

    @classmethod
    def setup_mappers(cls):
        mapper(cls.classes.Data, cls.tables.data)
        mapper(cls.classes.DataFetched, cls.tables.data_fetched)
        mapper(cls.classes.DataDefer, cls.tables.data_defer, properties={
            "data": deferred(cls.tables.data_defer.c.data)
        })

    def test_attr_not_inserted(self):
        Data = self.classes.Data

        sess = create_session()

        d1 = Data()
        sess.add(d1)
        sess.flush()

        # we didn't insert a value for 'data',
        # so its not in dict, but also when we hit it, it isn't
        # expired because there's no column default on it or anything like that
        assert 'data' not in d1.__dict__

        def go():
            eq_(d1.data, None)

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

    def test_attr_not_inserted_expired(self):
        Data = self.classes.Data

        sess = create_session()

        d1 = Data()
        sess.add(d1)
        sess.flush()

        assert 'data' not in d1.__dict__

        # with an expire, we emit
        sess.expire(d1)

        def go():
            eq_(d1.data, None)

        self.assert_sql_count(
            testing.db,
            go,
            1
        )

    def test_attr_not_inserted_fetched(self):
        Data = self.classes.DataFetched

        sess = create_session()

        d1 = Data()
        sess.add(d1)
        sess.flush()

        assert 'data' not in d1.__dict__

        def go():
            eq_(d1.data, None)

        # this one is marked as "fetch" so we emit SQL
        self.assert_sql_count(
            testing.db,
            go,
            1
        )

    def test_cols_missing_in_load(self):
        Data = self.classes.Data

        sess = create_session()

        d1 = Data(data='d1')
        sess.add(d1)
        sess.flush()
        sess.close()

        sess = create_session()
        d1 = sess.query(Data).from_statement(select([Data.id])).first()

        # cols not present in the row are implicitly expired
        def go():
            eq_(d1.data, 'd1')

        self.assert_sql_count(
            testing.db, go, 1
        )

    def test_deferred_cols_missing_in_load_state_reset(self):
        Data = self.classes.DataDefer

        sess = create_session()

        d1 = Data(data='d1')
        sess.add(d1)
        sess.flush()
        sess.close()

        sess = create_session()
        d1 = sess.query(Data).from_statement(
            select([Data.id])).options(undefer(Data.data)).first()
        d1.data = 'd2'

        # the deferred loader has to clear out any state
        # on the col, including that 'd2' here
        d1 = sess.query(Data).populate_existing().first()

        def go():
            eq_(d1.data, 'd1')

        self.assert_sql_count(
            testing.db, go, 1
        )


class RefreshTest(_fixtures.FixtureTest):

    def test_refresh(self):
        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(mapper(Address, addresses),
                                      backref='user')
        })
        s = create_session()
        u = s.query(User).get(7)
        u.name = 'foo'
        a = Address()
        assert sa.orm.object_session(a) is None
        u.addresses.append(a)
        assert a.email_address is None
        assert id(a) in [id(x) for x in u.addresses]

        s.refresh(u)

        # its refreshed, so not dirty
        assert u not in s.dirty

        # username is back to the DB
        assert u.name == 'jack'

        assert id(a) not in [id(x) for x in u.addresses]

        u.name = 'foo'
        u.addresses.append(a)
        # now its dirty
        assert u in s.dirty
        assert u.name == 'foo'
        assert id(a) in [id(x) for x in u.addresses]
        s.expire(u)

        # get the attribute, it refreshes
        assert u.name == 'jack'
        assert id(a) not in [id(x) for x in u.addresses]

    def test_persistence_check(self):
        users, User = self.tables.users, self.classes.User

        mapper(User, users)
        s = create_session()
        u = s.query(User).get(7)
        s.expunge_all()
        assert_raises_message(sa_exc.InvalidRequestError,
                              r"is not persistent within this Session",
                              lambda: s.refresh(u))

    def test_refresh_expired(self):
        User, users = self.classes.User, self.tables.users

        mapper(User, users)
        s = create_session()
        u = s.query(User).get(7)
        s.expire(u)
        assert 'name' not in u.__dict__
        s.refresh(u)
        assert u.name == 'jack'

    def test_refresh_with_lazy(self):
        """test that when a lazy loader is set as a trigger on an object's
        attribute (at the attribute level, not the class level), a refresh()
        operation doesn't fire the lazy loader or create any problems"""

        User, Address, addresses, users = (self.classes.User,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.tables.users)

        s = create_session()
        mapper(User, users, properties={
               'addresses': relationship(mapper(Address, addresses))})
        q = s.query(User).options(sa.orm.lazyload('addresses'))
        u = q.filter(users.c.id == 8).first()

        def go():
            s.refresh(u)
        self.assert_sql_count(testing.db, go, 1)

    def test_refresh_with_eager(self):
        """test that a refresh/expire operation loads rows properly and sends
        correct "isnew" state to eager loaders"""

        users, Address, addresses, User = (self.tables.users,
                                           self.classes.Address,
                                           self.tables.addresses,
                                           self.classes.User)

        mapper(User, users, properties={
            'addresses': relationship(mapper(Address, addresses),
                                      lazy='joined')
        })

        s = create_session()
        u = s.query(User).get(8)
        assert len(u.addresses) == 3
        s.refresh(u)
        assert len(u.addresses) == 3

        s = create_session()
        u = s.query(User).get(8)
        assert len(u.addresses) == 3
        s.expire(u)
        assert len(u.addresses) == 3

    def test_refresh_maintains_deferred_options(self):
        # testing a behavior that may have changed with
        # [ticket:3822]
        User, Address, Dingaling = self.classes(
            "User", "Address", "Dingaling")
        users, addresses, dingalings = self.tables(
            "users", "addresses", "dingalings")

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

        mapper(Address, addresses, properties={
            'dingalings': relationship(Dingaling)
        })

        mapper(Dingaling, dingalings)

        s = create_session()
        q = s.query(User).filter_by(name='fred').options(
            sa.orm.lazyload('addresses').joinedload("dingalings"))

        u1 = q.one()

        # "addresses" is not present on u1, but when u1.addresses
        # lazy loads, it should also joinedload dingalings.  This is
        # present in state.load_options and state.load_path.   The
        # refresh operation should not reset these attributes.
        s.refresh(u1)

        def go():
            eq_(
                u1.addresses,
                [Address(
                    email_address='fred@fred.com',
                    dingalings=[Dingaling(data="ding 2/5")]
                )]
            )

        self.assert_sql_count(testing.db, go, 1)

    def test_refresh2(self):
        """test a hang condition that was occurring on expire/refresh"""

        Address, addresses, users, User = (self.classes.Address,
                                           self.tables.addresses,
                                           self.tables.users,
                                           self.classes.User)

        s = create_session()
        mapper(Address, addresses)

        mapper(User, users, properties=dict(addresses=relationship(
            Address, cascade="all, delete-orphan", lazy='joined')))

        u = User()
        u.name = 'Justin'
        a = Address(id=10, email_address='lala')
        u.addresses.append(a)

        s.add(u)
        s.flush()
        s.expunge_all()
        u = s.query(User).filter(User.name == 'Justin').one()

        s.expire(u)
        assert u.name == 'Justin'

        s.refresh(u)