Flask SqlAlchemy begin and end transaction

Question

I'm writing a SqlAlchemy transaction in flask using sqlalchemy extension:

flask.ext.sqlalchemy

Here's how my code looks like:

def charge_user(user):
  db.session.begin()
  try:
    transaction = create_transaction()
    if not transaction:
      // cancel the session
      return False

    db.session.add(transaction)
    user.paid = True
    db.session.add(user)
    return True
  except Exception:
    db.session.rollback()
    return False

Just one quick question, the documentation of sqlalchemy extension vs the flask-sqlalchemy plugin are very confusing. How do I do cancel the session/transaction in case of flask-sqlalchemy extension.

Answer 1

How do I do cancel the session/transaction in case of flask-sqlalchemy extension.

That's what db.session.rollback() does.