sqlalchemy/test/orm/merge.py

import testenv; testenv.configure_for_tests()
from testlib import sa, testing
from testlib.sa.util import OrderedSet
from testlib.sa.orm import mapper, relation, create_session, PropComparator, synonym, comparable_property
from testlib.testing import eq_, ne_
from orm import _base, _fixtures


class MergeTest(_fixtures.FixtureTest):
    """Session..merge() functionality"""

    run_inserts = None

    def on_load_tracker(self, cls, canary=None):
        if canary is None:
            def canary(instance):
                canary.called += 1
            canary.called = 0

        manager = sa.orm.attributes.manager_of_class(cls)
        manager.events.add_listener('on_load', canary)

        return canary

    @testing.resolve_artifact_names
    def test_transient_to_pending(self):
        mapper(User, users)
        sess = create_session()
        on_load = self.on_load_tracker(User)

        u = User(id=7, name='fred')
        eq_(on_load.called, 0)
        u2 = sess.merge(u)
        eq_(on_load.called, 1)
        assert u2 in sess
        eq_(u2, User(id=7, name='fred'))
        sess.flush()
        sess.clear()
        eq_(sess.query(User).first(), User(id=7, name='fred'))

    @testing.resolve_artifact_names
    def test_transient_to_pending_collection(self):
        mapper(User, users, properties={
            'addresses': relation(Address, backref='user',
                                  collection_class=OrderedSet)})
        mapper(Address, addresses)
        on_load = self.on_load_tracker(User)
        self.on_load_tracker(Address, on_load)

        u = User(id=7, name='fred', addresses=OrderedSet([
            Address(id=1, email_address='fred1'),
            Address(id=2, email_address='fred2'),
            ]))
        eq_(on_load.called, 0)

        sess = create_session()
        sess.merge(u)
        eq_(on_load.called, 3)

        merged_users = [e for e in sess if isinstance(e, User)]
        eq_(len(merged_users), 1)
        assert merged_users[0] is not u

        sess.flush()
        sess.clear()

        eq_(sess.query(User).one(),
            User(id=7, name='fred', addresses=OrderedSet([
                Address(id=1, email_address='fred1'),
                Address(id=2, email_address='fred2'),
            ]))
        )

    @testing.resolve_artifact_names
    def test_transient_to_persistent(self):
        mapper(User, users)
        on_load = self.on_load_tracker(User)

        sess = create_session()
        u = User(id=7, name='fred')
        sess.add(u)
        sess.flush()
        sess.clear()

        eq_(on_load.called, 0)

        _u2 = u2 = User(id=7, name='fred jones')
        eq_(on_load.called, 0)
        u2 = sess.merge(u2)
        assert u2 is not _u2
        eq_(on_load.called, 1)
        sess.flush()
        sess.clear()
        eq_(sess.query(User).first(), User(id=7, name='fred jones'))
        eq_(on_load.called, 2)

    @testing.resolve_artifact_names
    def test_transient_to_persistent_collection(self):
        mapper(User, users, properties={
            'addresses':relation(Address,
                        backref='user',
                        collection_class=OrderedSet,
                                 cascade="all, delete-orphan")
        })
        mapper(Address, addresses)

        on_load = self.on_load_tracker(User)
        self.on_load_tracker(Address, on_load)

        u = User(id=7, name='fred', addresses=OrderedSet([
            Address(id=1, email_address='fred1'),
            Address(id=2, email_address='fred2'),
        ]))
        sess = create_session()
        sess.add(u)
        sess.flush()
        sess.clear()

        eq_(on_load.called, 0)

        u = User(id=7, name='fred', addresses=OrderedSet([
            Address(id=3, email_address='fred3'),
            Address(id=4, email_address='fred4'),
        ]))

        u = sess.merge(u)

        # 1. merges User object.  updates into session.
        # 2.,3. merges Address ids 3 & 4, saves into session.
        # 4.,5. loads pre-existing elements in "addresses" collection,
        # marks as deleted, Address ids 1 and 2.
        eq_(on_load.called, 5)

        eq_(u,
            User(id=7, name='fred', addresses=OrderedSet([
                Address(id=3, email_address='fred3'),
                Address(id=4, email_address='fred4'),
            ]))
        )
        sess.flush()
        sess.clear()
        eq_(sess.query(User).one(),
            User(id=7, name='fred', addresses=OrderedSet([
                Address(id=3, email_address='fred3'),
                Address(id=4, email_address='fred4'),
            ]))
        )

    @testing.resolve_artifact_names
    def test_detached_to_persistent_collection(self):
        mapper(User, users, properties={
            'addresses':relation(Address,
                                 backref='user',
                                 collection_class=OrderedSet)})
        mapper(Address, addresses)
        on_load = self.on_load_tracker(User)
        self.on_load_tracker(Address, on_load)

        a = Address(id=1, email_address='fred1')
        u = User(id=7, name='fred', addresses=OrderedSet([
            a,
            Address(id=2, email_address='fred2'),
        ]))
        sess = create_session()
        sess.add(u)
        sess.flush()
        sess.clear()

        u.name='fred jones'
        u.addresses.add(Address(id=3, email_address='fred3'))
        u.addresses.remove(a)

        eq_(on_load.called, 0)
        u = sess.merge(u)
        eq_(on_load.called, 4)
        sess.flush()
        sess.clear()

        eq_(sess.query(User).first(),
            User(id=7, name='fred jones', addresses=OrderedSet([
                Address(id=2, email_address='fred2'),
                Address(id=3, email_address='fred3')])))

    @testing.resolve_artifact_names
    def test_unsaved_cascade(self):
        """Merge of a transient entity with two child transient entities, with a bidirectional relation."""

        mapper(User, users, properties={
            'addresses':relation(mapper(Address, addresses),
                                 cascade="all", backref="user")
        })
        on_load = self.on_load_tracker(User)
        self.on_load_tracker(Address, on_load)
        sess = create_session()

        u = User(id=7, name='fred')
        a1 = Address(email_address='foo@bar.com')
        a2 = Address(email_address='hoho@bar.com')
        u.addresses.append(a1)
        u.addresses.append(a2)

        u2 = sess.merge(u)
        eq_(on_load.called, 3)

        eq_(u,
            User(id=7, name='fred', addresses=[
              Address(email_address='foo@bar.com'),
              Address(email_address='hoho@bar.com')]))
        eq_(u2,
            User(id=7, name='fred', addresses=[
              Address(email_address='foo@bar.com'),
              Address(email_address='hoho@bar.com')]))

        sess.flush()
        sess.clear()
        u2 = sess.query(User).get(7)

        eq_(u2, User(id=7, name='fred', addresses=[
            Address(email_address='foo@bar.com'),
            Address(email_address='hoho@bar.com')]))
        eq_(on_load.called, 6)

    @testing.resolve_artifact_names
    def test_attribute_cascade(self):
        """Merge of a persistent entity with two child persistent entities."""

        mapper(User, users, properties={
            'addresses':relation(mapper(Address, addresses), backref='user')
        })
        on_load = self.on_load_tracker(User)
        self.on_load_tracker(Address, on_load)

        sess = create_session()

        # set up data and save
        u = User(id=7, name='fred', addresses=[
            Address(email_address='foo@bar.com'),
            Address(email_address = 'hoho@la.com')])
        sess.add(u)
        sess.flush()

        # assert data was saved
        sess2 = create_session()
        u2 = sess2.query(User).get(7)
        eq_(u2,
            User(id=7, name='fred', addresses=[
              Address(email_address='foo@bar.com'),
              Address(email_address='hoho@la.com')]))

        # make local changes to data
        u.name = 'fred2'
        u.addresses[1].email_address = 'hoho@lalala.com'

        eq_(on_load.called, 3)

        # new session, merge modified data into session
        sess3 = create_session()
        u3 = sess3.merge(u)
        eq_(on_load.called, 6)

        # ensure local changes are pending
        eq_(u3, User(id=7, name='fred2', addresses=[
            Address(email_address='foo@bar.com'),
            Address(email_address='hoho@lalala.com')]))

        # save merged data
        sess3.flush()

        # assert modified/merged data was saved
        sess.clear()
        u = sess.query(User).get(7)
        eq_(u, User(id=7, name='fred2', addresses=[
            Address(email_address='foo@bar.com'),
            Address(email_address='hoho@lalala.com')]))
        eq_(on_load.called, 9)

        # merge persistent object into another session
        sess4 = create_session()
        u = sess4.merge(u)
        assert len(u.addresses)
        for a in u.addresses:
            assert a.user is u
        def go():
            sess4.flush()
        # no changes; therefore flush should do nothing
        self.assert_sql_count(testing.db, go, 0)
        eq_(on_load.called, 12)

        # test with "dontload" merge
        sess5 = create_session()
        u = sess5.merge(u, dont_load=True)
        assert len(u.addresses)
        for a in u.addresses:
            assert a.user is u
        def go():
            sess5.flush()
        # no changes; therefore flush should do nothing
        # but also, dont_load wipes out any difference in committed state,
        # so no flush at all
        self.assert_sql_count(testing.db, go, 0)
        eq_(on_load.called, 15)

        sess4 = create_session()
        u = sess4.merge(u, dont_load=True)
        # post merge change
        u.addresses[1].email_address='afafds'
        def go():
            sess4.flush()
        # afafds change flushes
        self.assert_sql_count(testing.db, go, 1)
        eq_(on_load.called, 18)

        sess5 = create_session()
        u2 = sess5.query(User).get(u.id)
        eq_(u2.name, 'fred2')
        eq_(u2.addresses[1].email_address, 'afafds')
        eq_(on_load.called, 21)

    @testing.resolve_artifact_names
    def test_one_to_many_cascade(self):

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

        on_load = self.on_load_tracker(User)
        self.on_load_tracker(Address, on_load)

        sess = create_session()
        u = User(name='fred')
        a1 = Address(email_address='foo@bar')
        a2 = Address(email_address='foo@quux')
        u.addresses.extend([a1, a2])

        sess.add(u)
        sess.flush()

        eq_(on_load.called, 0)

        sess2 = create_session()
        u2 = sess2.query(User).get(u.id)
        eq_(on_load.called, 1)

        u.addresses[1].email_address = 'addr 2 modified'
        sess2.merge(u)
        eq_(u2.addresses[1].email_address, 'addr 2 modified')
        eq_(on_load.called, 3)

        sess3 = create_session()
        u3 = sess3.query(User).get(u.id)
        eq_(on_load.called, 4)

        u.name = 'also fred'
        sess3.merge(u)
        eq_(on_load.called, 6)
        eq_(u3.name, 'also fred')

    @testing.resolve_artifact_names
    def test_many_to_many_cascade(self):

        mapper(Order, orders, properties={
            'items':relation(mapper(Item, items), secondary=order_items)})

        on_load = self.on_load_tracker(Order)
        self.on_load_tracker(Item, on_load)

        sess = create_session()

        i1 = Item()
        i1.description='item 1'

        i2 = Item()
        i2.description = 'item 2'

        o = Order()
        o.description = 'order description'
        o.items.append(i1)
        o.items.append(i2)

        sess.add(o)
        sess.flush()

        eq_(on_load.called, 0)

        sess2 = create_session()
        o2 = sess2.query(Order).get(o.id)
        eq_(on_load.called, 1)

        o.items[1].description = 'item 2 modified'
        sess2.merge(o)
        eq_(o2.items[1].description, 'item 2 modified')
        eq_(on_load.called,  3)

        sess3 = create_session()
        o3 = sess3.query(Order).get(o.id)
        eq_( on_load.called, 4)

        o.description = 'desc modified'
        sess3.merge(o)
        eq_(on_load.called, 6)
        eq_(o3.description, 'desc modified')

    @testing.resolve_artifact_names
    def test_one_to_one_cascade(self):

        mapper(User, users, properties={
            'address':relation(mapper(Address, addresses),uselist = False)
        })
        on_load = self.on_load_tracker(User)
        self.on_load_tracker(Address, on_load)
        sess = create_session()

        u = User()
        u.id = 7
        u.name = "fred"
        a1 = Address()
        a1.email_address='foo@bar.com'
        u.address = a1

        sess.add(u)
        sess.flush()

        eq_(on_load.called, 0)

        sess2 = create_session()
        u2 = sess2.query(User).get(7)
        eq_(on_load.called, 1)
        u2.name = 'fred2'
        u2.address.email_address = 'hoho@lalala.com'
        eq_(on_load.called, 2)

        u3 = sess.merge(u2)
        eq_(on_load.called, 2)
        assert u3 is u

    @testing.resolve_artifact_names
    def test_transient_dontload(self):
        mapper(User, users)

        sess = create_session()
        u = User()
        self.assertRaisesMessage(sa.exc.InvalidRequestError, "dont_load=True option does not support", sess.merge, u, dont_load=True)


    @testing.resolve_artifact_names
    def test_dontload_with_backrefs(self):
        """dontload populates relations in both directions without requiring a load"""
        mapper(User, users, properties={
            'addresses':relation(mapper(Address, addresses), backref='user')
        })

        u = User(id=7, name='fred', addresses=[
            Address(email_address='ad1'),
            Address(email_address='ad2')])
        sess = create_session()
        sess.add(u)
        sess.flush()
        sess.close()
        assert 'user' in u.addresses[1].__dict__

        sess = create_session()
        u2 = sess.merge(u, dont_load=True)
        assert 'user' in u2.addresses[1].__dict__
        eq_(u2.addresses[1].user, User(id=7, name='fred'))

        sess.expire(u2.addresses[1], ['user'])
        assert 'user' not in u2.addresses[1].__dict__
        sess.close()

        sess = create_session()
        u = sess.merge(u2, dont_load=True)
        assert 'user' not in u.addresses[1].__dict__
        eq_(u.addresses[1].user, User(id=7, name='fred'))


    @testing.resolve_artifact_names
    def test_dontload_with_eager(self):
        """

        This test illustrates that with dont_load=True, we can't just copy the
        committed_state of the merged instance over; since it references
        collection objects which themselves are to be merged.  This
        committed_state would instead need to be piecemeal 'converted' to
        represent the correct objects.  However, at the moment I'd rather not
        support this use case; if you are merging with dont_load=True, you're
        typically dealing with caching and the merged objects shouldnt be
        'dirty'.

        """
        mapper(User, users, properties={
            'addresses':relation(mapper(Address, addresses))
        })
        sess = create_session()
        u = User()
        u.id = 7
        u.name = "fred"
        a1 = Address()
        a1.email_address='foo@bar.com'
        u.addresses.append(a1)

        sess.add(u)
        sess.flush()

        sess2 = create_session()
        u2 = sess2.query(User).options(sa.orm.eagerload('addresses')).get(7)

        sess3 = create_session()
        u3 = sess3.merge(u2, dont_load=True)
        def go():
            sess3.flush()
        self.assert_sql_count(testing.db, go, 0)

    @testing.resolve_artifact_names
    def test_dont_load_disallows_dirty(self):
        """dont_load doesnt support 'dirty' objects right now

        (see test_dont_load_with_eager()). Therefore lets assert it.

        """
        mapper(User, users)
        sess = create_session()
        u = User()
        u.id = 7
        u.name = "fred"
        sess.add(u)
        sess.flush()

        u.name = 'ed'
        sess2 = create_session()
        try:
            sess2.merge(u, dont_load=True)
            assert False
        except sa.exc.InvalidRequestError, e:
            assert ("merge() with dont_load=True option does not support "
                    "objects marked as 'dirty'.  flush() all changes on mapped "
                    "instances before merging with dont_load=True.") in str(e)

        u2 = sess2.query(User).get(7)

        sess3 = create_session()
        u3 = sess3.merge(u2, dont_load=True)
        assert not sess3.dirty
        def go():
            sess3.flush()
        self.assert_sql_count(testing.db, go, 0)


    @testing.resolve_artifact_names
    def test_dont_load_sets_backrefs(self):
        mapper(User, users, properties={
            'addresses':relation(mapper(Address, addresses),backref='user')})

        sess = create_session()
        u = User()
        u.id = 7
        u.name = "fred"
        a1 = Address()
        a1.email_address='foo@bar.com'
        u.addresses.append(a1)

        sess.add(u)
        sess.flush()

        assert u.addresses[0].user is u

        sess2 = create_session()
        u2 = sess2.merge(u, dont_load=True)
        assert not sess2.dirty
        def go():
            assert u2.addresses[0].user is u2
        self.assert_sql_count(testing.db, go, 0)

    @testing.resolve_artifact_names
    def test_dont_load_preserves_parents(self):
        """Merge with dont_load does not trigger a 'delete-orphan' operation.

        merge with dont_load sets attributes without using events.  this means
        the 'hasparent' flag is not propagated to the newly merged instance.
        in fact this works out OK, because the '_state.parents' collection on
        the newly merged instance is empty; since the mapper doesn't see an
        active 'False' setting in this collection when _is_orphan() is called,
        it does not count as an orphan (i.e. this is the 'optimistic' logic in
        mapper._is_orphan().)

        """
        mapper(User, users, properties={
            'addresses':relation(mapper(Address, addresses),
                                 backref='user', cascade="all, delete-orphan")})
        sess = create_session()
        u = User()
        u.id = 7
        u.name = "fred"
        a1 = Address()
        a1.email_address='foo@bar.com'
        u.addresses.append(a1)
        sess.add(u)
        sess.flush()

        assert u.addresses[0].user is u

        sess2 = create_session()
        u2 = sess2.merge(u, dont_load=True)
        assert not sess2.dirty
        a2 = u2.addresses[0]
        a2.email_address='somenewaddress'
        assert not sa.orm.object_mapper(a2)._is_orphan(
            sa.orm.attributes.instance_state(a2))
        sess2.flush()
        sess2.clear()

        eq_(sess2.query(User).get(u2.id).addresses[0].email_address,
            'somenewaddress')

        # this use case is not supported; this is with a pending Address on
        # the pre-merged object, and we currently dont support 'dirty' objects
        # being merged with dont_load=True.  in this case, the empty
        # '_state.parents' collection would be an issue, since the optimistic
        # flag is False in _is_orphan() for pending instances.  so if we start
        # supporting 'dirty' with dont_load=True, this test will need to pass
        sess = create_session()
        u = sess.query(User).get(7)
        u.addresses.append(Address())
        sess2 = create_session()
        try:
            u2 = sess2.merge(u, dont_load=True)
            assert False

            # if dont_load is changed to support dirty objects, this code
            # needs to pass
            a2 = u2.addresses[0]
            a2.email_address='somenewaddress'
            assert not sa.orm.object_mapper(a2)._is_orphan(
                sa.orm.attributes.instance_state(a2))
            sess2.flush()
            sess2.clear()
            eq_(sess2.query(User).get(u2.id).addresses[0].email_address,
                'somenewaddress')
        except sa.exc.InvalidRequestError, e:
            assert "dont_load=True option does not support" in str(e)

    @testing.resolve_artifact_names
    def test_synonym_comparable(self):
        class User(object):

           class Comparator(PropComparator):
               pass

           def _getValue(self):
               return self._value

           def _setValue(self, value):
               setattr(self, '_value', value)

           value = property(_getValue, _setValue)

        mapper(User, users, properties={
            'uid':synonym('id'),
            'foobar':comparable_property(User.Comparator,User.value),
        })
        
        sess = create_session()
        u = User()
        u.name = 'ed'
        sess.save(u)
        sess.flush()
        sess.expunge(u)
        sess.merge(u)

if __name__ == "__main__":
    testenv.main()