from sqlalchemy import create_engine, Column
from sqlalchemy.types import Integer
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.event import listens_for
 
 
Base = declarative_base()
Session = scoped_session(sessionmaker())

 
class MyModel(Base):
    __tablename__ = "MyTable"
    priid = Column(Integer(), primary_key=True)
    secid = Column(Integer())
 
 
@listens_for(MyModel, 'after_insert')
def mymodel_after_insert(mapper, connection, target):
    mytable = MyModel.__table__
    priid = target.priid
    statement = (mytable.update()
                    .where(mytable.c.priid == priid)
                    .values(secid=priid))
    connection.execute(statement)
 
 
if __name__ == '__main__':
    engine = create_engine('sqlite://', echo=True)
    Base.metadata.create_all(bind=engine)
    Session.configure(bind=engine)
 
    # Add 10 rows
    for i in xrange(10):
        Session.add(MyModel())

    Session.commit()
    Session.remove()
   
    # Check the rows
    rows = Session.query(MyModel).all()
    for row in rows:
        assert row.secid == row.priid

    print("Checked %s rows." % len(rows))