"""The collection of modern alternatives to deprecated & removed functionality. Collects specimens of old ORM code and explicitly covers the recommended modern (i.e. not deprecated) alternative to them. The tests snippets here can be migrated directly to the wiki, docs, etc. """ from sqlalchemy import testing from sqlalchemy import Integer, String, ForeignKey, func from sqlalchemy.testing.schema import Table from sqlalchemy.testing.schema import Column from sqlalchemy.orm import mapper, relationship, relation, create_session, sessionmaker from sqlalchemy.testing import fixtures class QueryAlternativesTest(fixtures.MappedTest): '''Collects modern idioms for Queries The docstring for each test case serves as miniature documentation about the deprecated use case, and the test body illustrates (and covers) the intended replacement code to accomplish the same task. Documenting the "old way" including the argument signature helps these cases remain useful to readers even after the deprecated method has been removed from the modern codebase. Format: def test_deprecated_thing(self): """Query.methodname(old, arg, **signature) output = session.query(User).deprecatedmethod(inputs) """ # 0.4+ output = session.query(User).newway(inputs) assert output is correct # 0.5+ output = session.query(User).evennewerway(inputs) assert output is correct ''' run_inserts = 'once' run_deletes = None @classmethod def define_tables(cls, metadata): Table('users_table', metadata, Column('id', Integer, primary_key=True), Column('name', String(64))) Table('addresses_table', metadata, Column('id', Integer, primary_key=True), Column('user_id', Integer, ForeignKey('users_table.id')), Column('email_address', String(128)), Column('purpose', String(16)), Column('bounces', Integer, default=0)) @classmethod def setup_classes(cls): class User(cls.Basic): pass class Address(cls.Basic): pass @classmethod def setup_mappers(cls): addresses_table, User, users_table, Address = (cls.tables.addresses_table, cls.classes.User, cls.tables.users_table, cls.classes.Address) mapper(User, users_table, properties=dict( addresses=relationship(Address, backref='user'), )) mapper(Address, addresses_table) @classmethod def fixtures(cls): return dict( users_table=( ('id', 'name'), (1, 'jack'), (2, 'ed'), (3, 'fred'), (4, 'chuck')), addresses_table=( ('id', 'user_id', 'email_address', 'purpose', 'bounces'), (1, 1, 'jack@jack.home', 'Personal', 0), (2, 1, 'jack@jack.bizz', 'Work', 1), (3, 2, 'ed@foo.bar', 'Personal', 0), (4, 3, 'fred@the.fred', 'Personal', 10))) ###################################################################### def test_override_get(self): """MapperExtension.get() x = session.query.get(5) """ Address = self.classes.Address from sqlalchemy.orm.query import Query cache = {} class MyQuery(Query): def get(self, ident, **kwargs): if ident in cache: return cache[ident] else: x = super(MyQuery, self).get(ident) cache[ident] = x return x session = sessionmaker(query_cls=MyQuery)() ad1 = session.query(Address).get(1) assert ad1 in list(cache.values()) def test_load(self): """x = session.query(Address).load(1) x = session.load(Address, 1) """ Address = self.classes.Address session = create_session() ad1 = session.query(Address).populate_existing().get(1) assert bool(ad1) def test_apply_max(self): """Query.apply_max(col) max = session.query(Address).apply_max(Address.bounces) """ Address = self.classes.Address session = create_session() # 0.5.0 maxes = list(session.query(Address).values(func.max(Address.bounces))) max = maxes[0][0] assert max == 10 max = session.query(func.max(Address.bounces)).one()[0] assert max == 10 def test_apply_min(self): """Query.apply_min(col) min = session.query(Address).apply_min(Address.bounces) """ Address = self.classes.Address session = create_session() # 0.5.0 mins = list(session.query(Address).values(func.min(Address.bounces))) min = mins[0][0] assert min == 0 min = session.query(func.min(Address.bounces)).one()[0] assert min == 0 def test_apply_avg(self): """Query.apply_avg(col) avg = session.query(Address).apply_avg(Address.bounces) """ Address = self.classes.Address session = create_session() avgs = list(session.query(Address).values(func.avg(Address.bounces))) avg = avgs[0][0] assert avg > 0 and avg < 10 avg = session.query(func.avg(Address.bounces)).one()[0] assert avg > 0 and avg < 10 def test_apply_sum(self): """Query.apply_sum(col) avg = session.query(Address).apply_avg(Address.bounces) """ Address = self.classes.Address session = create_session() avgs = list(session.query(Address).values(func.sum(Address.bounces))) avg = avgs[0][0] assert avg == 11 avg = session.query(func.sum(Address.bounces)).one()[0] assert avg == 11 def test_count_by(self): """Query.count_by(*args, **params) num = session.query(Address).count_by(purpose='Personal') # old-style implicit *_by join num = session.query(User).count_by(purpose='Personal') """ User, Address = self.classes.User, self.classes.Address session = create_session() num = session.query(Address).filter_by(purpose='Personal').count() assert num == 3, num num = (session.query(User).join('addresses'). filter(Address.purpose=='Personal')).count() assert num == 3, num def test_count_whereclause(self): """Query.count(whereclause=None, params=None, **kwargs) num = session.query(Address).count(address_table.c.bounces > 1) """ Address = self.classes.Address session = create_session() num = session.query(Address).filter(Address.bounces > 1).count() assert num == 1, num def test_execute(self): """Query.execute(clauseelement, params=None, *args, **kwargs) users = session.query(User).execute(users_table.select()) """ User, users_table = self.classes.User, self.tables.users_table session = create_session() users = session.query(User).from_statement(users_table.select()).all() assert len(users) == 4 def test_get_by(self): """Query.get_by(*args, **params) user = session.query(User).get_by(name='ed') # 0.3-style implicit *_by join user = session.query(User).get_by(email_addresss='fred@the.fred') """ User, Address = self.classes.User, self.classes.Address session = create_session() user = session.query(User).filter_by(name='ed').first() assert user.name == 'ed' user = (session.query(User).join('addresses'). filter(Address.email_address=='fred@the.fred')).first() assert user.name == 'fred' user = session.query(User).filter( User.addresses.any(Address.email_address=='fred@the.fred')).first() assert user.name == 'fred' def test_instances_entities(self): """Query.instances(cursor, *mappers_or_columns, **kwargs) sel = users_table.join(addresses_table).select(use_labels=True) res = session.query(User).instances(sel.execute(), Address) """ addresses_table, User, users_table, Address = (self.tables.addresses_table, self.classes.User, self.tables.users_table, self.classes.Address) session = create_session() sel = users_table.join(addresses_table).select(use_labels=True) res = list(session.query(User, Address).instances(sel.execute())) assert len(res) == 4 cola, colb = res[0] assert isinstance(cola, User) and isinstance(colb, Address) def test_join_by(self): """Query.join_by(*args, **params) TODO """ session = create_session() def test_join_to(self): """Query.join_to(key) TODO """ session = create_session() def test_join_via(self): """Query.join_via(keys) TODO """ session = create_session() def test_list(self): """Query.list() users = session.query(User).list() """ User = self.classes.User session = create_session() users = session.query(User).all() assert len(users) == 4 def test_scalar(self): """Query.scalar() user = session.query(User).filter(User.id==1).scalar() """ User = self.classes.User session = create_session() user = session.query(User).filter(User.id==1).first() assert user.id==1 def test_select(self): """Query.select(arg=None, **kwargs) users = session.query(User).select(users_table.c.name != None) """ User = self.classes.User session = create_session() users = session.query(User).filter(User.name != None).all() assert len(users) == 4 def test_select_by(self): """Query.select_by(*args, **params) users = session.query(User).select_by(name='fred') # 0.3 magic join on *_by methods users = session.query(User).select_by(email_address='fred@the.fred') """ User, Address = self.classes.User, self.classes.Address session = create_session() users = session.query(User).filter_by(name='fred').all() assert len(users) == 1 users = session.query(User).filter(User.name=='fred').all() assert len(users) == 1 users = (session.query(User).join('addresses'). filter_by(email_address='fred@the.fred')).all() assert len(users) == 1 users = session.query(User).filter(User.addresses.any( Address.email_address == 'fred@the.fred')).all() assert len(users) == 1 def test_selectfirst(self): """Query.selectfirst(arg=None, **kwargs) bounced = session.query(Address).selectfirst( addresses_table.c.bounces > 0) """ Address = self.classes.Address session = create_session() bounced = session.query(Address).filter(Address.bounces > 0).first() assert bounced.bounces > 0 def test_selectfirst_by(self): """Query.selectfirst_by(*args, **params) onebounce = session.query(Address).selectfirst_by(bounces=1) # 0.3 magic join on *_by methods onebounce_user = session.query(User).selectfirst_by(bounces=1) """ User, Address = self.classes.User, self.classes.Address session = create_session() onebounce = session.query(Address).filter_by(bounces=1).first() assert onebounce.bounces == 1 onebounce_user = (session.query(User).join('addresses'). filter_by(bounces=1)).first() assert onebounce_user.name == 'jack' onebounce_user = (session.query(User).join('addresses'). filter(Address.bounces == 1)).first() assert onebounce_user.name == 'jack' onebounce_user = session.query(User).filter(User.addresses.any( Address.bounces == 1)).first() assert onebounce_user.name == 'jack' def test_selectone(self): """Query.selectone(arg=None, **kwargs) ed = session.query(User).selectone(users_table.c.name == 'ed') """ User = self.classes.User session = create_session() ed = session.query(User).filter(User.name == 'jack').one() def test_selectone_by(self): """Query.selectone_by ed = session.query(User).selectone_by(name='ed') # 0.3 magic join on *_by methods ed = session.query(User).selectone_by(email_address='ed@foo.bar') """ User, Address = self.classes.User, self.classes.Address session = create_session() ed = session.query(User).filter_by(name='jack').one() ed = session.query(User).filter(User.name == 'jack').one() ed = session.query(User).join('addresses').filter( Address.email_address == 'ed@foo.bar').one() ed = session.query(User).filter(User.addresses.any( Address.email_address == 'ed@foo.bar')).one() def test_select_statement(self): """Query.select_statement(statement, **params) users = session.query(User).select_statement(users_table.select()) """ User, users_table = self.classes.User, self.tables.users_table session = create_session() users = session.query(User).from_statement(users_table.select()).all() assert len(users) == 4 def test_select_text(self): """Query.select_text(text, **params) users = session.query(User).select_text('SELECT * FROM users_table') """ User = self.classes.User session = create_session() users = (session.query(User). from_statement('SELECT * FROM users_table')).all() assert len(users) == 4 def test_select_whereclause(self): """Query.select_whereclause(whereclause=None, params=None, **kwargs) users = session,query(User).select_whereclause(users.c.name=='ed') users = session.query(User).select_whereclause("name='ed'") """ User = self.classes.User session = create_session() users = session.query(User).filter(User.name=='ed').all() assert len(users) == 1 and users[0].name == 'ed' users = session.query(User).filter("name='ed'").all() assert len(users) == 1 and users[0].name == 'ed'