import sqlalchemy as sa from sqlalchemy_utils.aggregates import aggregated from tests import TestCase class TestAggregateValueGenerationWithCascadeDelete(TestCase): dns = 'postgres://postgres@localhost/sqlalchemy_utils_test' def create_models(self): class Thread(self.Base): __tablename__ = 'thread' id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.Unicode(255)) @aggregated('comments', sa.Column(sa.Integer, default=0)) def comment_count(self): return sa.func.count('1') comments = sa.orm.relationship( 'Comment', passive_deletes=True, backref='thread' ) class Comment(self.Base): __tablename__ = 'comment' id = sa.Column(sa.Integer, primary_key=True) content = sa.Column(sa.Unicode(255)) thread_id = sa.Column( sa.Integer, sa.ForeignKey('thread.id', ondelete='CASCADE') ) self.Thread = Thread self.Comment = Comment def test_something(self): thread = self.Thread() thread.name = u'some article name' self.session.add(thread) comment = self.Comment(content=u'Some content', thread=thread) self.session.add(comment) self.session.commit() self.session.expire_all() self.session.delete(thread) self.session.commit()