class NaturalPKTest(ORMTest):

    def define_tables(self, metadata):
        global users, addresses, items

        users = Table('users', metadata,
            Column('username', String(50), primary_key=True),
            Column('fullname', String(100)))

        addresses = Table('addresses', metadata,
            Column('email', String(50), primary_key=True),
            Column('username', String(50),
                   ForeignKey('users.username', onupdate="cascade")))

        items = Table('items', metadata,
            Column('itemname', String(50), primary_key=True),
            Column('description', String(100)))

    def test_entity(self):
        mapper(User, users)

        sess = create_session()
        u1 = User(username='jack', fullname='jack')

        sess.save(u1)
        sess.flush()
        assert sess.get(User, 'jack') is u1

    def test_expiry(self):
        mapper(User, users)

        sess = create_session()
        u1 = User(username='jack', fullname='jack')

        sess.save(u1)
        sess.flush()
        assert sess.get(User, 'jack') is u1

        users.update(values={u1.c.username:'jack'}).execute(username='ed')

        try:
            # expire/refresh works off of primary key.  the PK is gone
            # in this case so theres no way to look it up.  criterion-
            # based session invalidation could solve this [ticket:911]
            sess.expire(u1)
            u1.username
            assert False
        except exceptions.InvalidRequestError, e:
            assert "Could not refresh instance" in str(e)

        sess.clear()
        assert sess.get(User, 'jack') is None
        assert sess.get(User, 'ed').fullname == 'jack'