在sqlalchemy中关闭会话

Question

I have created a method in seperate python file. Whenever I have to get any data from database I call this method. Now I am doing a for loop where for every iteration, db call is made to below method for ex-

 def get_method(self, identifier):
        sess = session.get_session()
        id = sess.query(..).filter(I.. == ..)
        return list(id)[0]


def get_session():
    engine = create_engine('postgresql+psycopg2://postgres:postgres@localhost/db', echo=True)
    Session = sessionmaker(engine)
    sess = Session()
    return sess

I am getting FATAL: sorry, too many clients already , probably because I am not closing the sess object . Even after closing I am getting the same issue.

How do I handle this.

Answer 1

You shouldn't be opening your session within the for loop. Do that before your loop begins, and close it after you're finished with your transactions. The documentation is helpful here: when to open and close sessions