sqlalchemy/test/ext/test_serializer.py

from sqlalchemy.ext import serializer
from sqlalchemy import exc
import sqlalchemy as sa
from sqlalchemy import testing
from sqlalchemy import MetaData, Integer, String, ForeignKey, select, \
    desc, func, util
from sqlalchemy.testing.schema import Table
from sqlalchemy.testing.schema import Column
from sqlalchemy.orm import relationship, sessionmaker, scoped_session, \
    class_mapper, mapper, joinedload, configure_mappers, aliased
from sqlalchemy.testing import eq_

from sqlalchemy.testing import fixtures

class User(fixtures.ComparableEntity):
    pass

class Address(fixtures.ComparableEntity):
    pass


class SerializeTest(fixtures.MappedTest):

    run_setup_mappers = 'once'
    run_inserts = 'once'
    run_deletes = None

    @classmethod
    def define_tables(cls, metadata):
        global users, addresses
        users = Table('users', metadata, Column('id', Integer,
                      primary_key=True), Column('name', String(50)))
        addresses = Table('addresses', metadata, Column('id', Integer,
                          primary_key=True), Column('email',
                          String(50)), Column('user_id', Integer,
                          ForeignKey('users.id')))

    @classmethod
    def setup_mappers(cls):
        global Session
        Session = scoped_session(sessionmaker())
        mapper(User, users, properties={'addresses'
               : relationship(Address, backref='user',
               order_by=addresses.c.id)})
        mapper(Address, addresses)
        configure_mappers()

    @classmethod
    def insert_data(cls):
        params = [dict(zip(('id', 'name'), column_values))
                  for column_values in [(7, 'jack'), (8, 'ed'), (9,
                  'fred'), (10, 'chuck')]]
        users.insert().execute(params)
        addresses.insert().execute([dict(zip(('id', 'user_id', 'email'
                                   ), column_values))
                                   for column_values in [(1, 7,
                                   'jack@bean.com'), (2, 8,
                                   'ed@wood.com'), (3, 8,
                                   'ed@bettyboop.com'), (4, 8,
                                   'ed@lala.com'), (5, 9,
                                   'fred@fred.com')]])

    def test_tables(self):
        assert serializer.loads(serializer.dumps(users, -1),
                                users.metadata, Session) is users

    def test_columns(self):
        assert serializer.loads(serializer.dumps(users.c.name, -1),
                                users.metadata, Session) is users.c.name

    def test_mapper(self):
        user_mapper = class_mapper(User)
        assert serializer.loads(serializer.dumps(user_mapper, -1),
                                None, None) is user_mapper

    def test_attribute(self):
        assert serializer.loads(serializer.dumps(User.name, -1), None,
                                None) is User.name

    @testing.requires.python26  # crashes in 2.5
    def test_expression(self):
        expr = \
            select([users]).select_from(users.join(addresses)).limit(5)
        re_expr = serializer.loads(serializer.dumps(expr, -1),
                                   users.metadata, None)
        eq_(str(expr), str(re_expr))
        assert re_expr.bind is testing.db
        eq_(re_expr.execute().fetchall(), [(7, u'jack'), (8, u'ed'),
            (8, u'ed'), (8, u'ed'), (9, u'fred')])

    @testing.requires.python26  # namedtuple workaround not serializable in 2.5
    @testing.skip_if(lambda: util.pypy, "pickle sometimes has "
                        "problems here, sometimes not")
    def test_query(self):
        q = Session.query(User).filter(User.name == 'ed'
                ).options(joinedload(User.addresses))
        eq_(q.all(), [User(name='ed', addresses=[Address(id=2),
            Address(id=3), Address(id=4)])])
        q2 = serializer.loads(serializer.dumps(q, -1), users.metadata,
                              Session)

        def go():
            eq_(q2.all(), [User(name='ed', addresses=[Address(id=2),
                Address(id=3), Address(id=4)])])

        self.assert_sql_count(testing.db, go, 1)
        eq_(q2.join(User.addresses).filter(Address.email
            == 'ed@bettyboop.com').value(func.count('*')), 1)
        u1 = Session.query(User).get(8)
        q = Session.query(Address).filter(Address.user
                == u1).order_by(desc(Address.email))
        q2 = serializer.loads(serializer.dumps(q, -1), users.metadata,
                              Session)
        eq_(q2.all(), [Address(email='ed@wood.com'),
            Address(email='ed@lala.com'),
            Address(email='ed@bettyboop.com')])

        # unfortunately pickle just doesn't have the horsepower
        # to pickle annotated joins, both cpickle and pickle
        # get confused likely since identity-unequal/hash equal
        # objects with cycles being used
        #q = \
        #    Session.query(User).join(User.addresses).\
        #       filter(Address.email.like('%fred%'))
        #q2 = serializer.loads(serializer.dumps(q, -1), users.metadata,
        #                      Session)
        #eq_(q2.all(), [User(name='fred')])
        #eq_(list(q2.values(User.id, User.name)), [(9, u'fred')])

    @testing.requires.python26 # namedtuple workaround not serializable in 2.5
    @testing.exclude('sqlite', '<=', (3, 5, 9),
                     'id comparison failing on the buildbot')
    def test_aliases(self):
        u7, u8, u9, u10 = Session.query(User).order_by(User.id).all()
        ualias = aliased(User)
        q = Session.query(User, ualias).join(ualias, User.id
                < ualias.id).filter(User.id < 9).order_by(User.id,
                ualias.id)
        eq_(list(q.all()), [(u7, u8), (u7, u9), (u7, u10), (u8, u9),
            (u8, u10)])
        q2 = serializer.loads(serializer.dumps(q, -1), users.metadata,
                              Session)
        eq_(list(q2.all()), [(u7, u8), (u7, u9), (u7, u10), (u8, u9),
            (u8, u10)])

    @testing.skip_if(lambda: util.pypy, "pickle sometimes has "
                        "problems here, sometimes not")
    def test_any(self):
        r = User.addresses.any(Address.email == 'x')
        ser = serializer.dumps(r, -1)
        x = serializer.loads(ser, users.metadata)
        eq_(str(r), str(x))


if __name__ == '__main__':
    testing.main()