def sql_function(func):
    """
    Decorator for wrapping the given function in order to manipulate (CRUD)
    the records safely.

    For the adding/updating/deleting records function, this decorator
    invokes "Session.commit()" after the given function.
    If any exception while modifying records raised, this decorator invokes
    "Session.rollbacks()".
    """
    @functools.wraps(func)
    def _wrapper(session, *args, **kwargs):
        ret = None
        try:
            ret = func(session, *args, **kwargs)
            if session.dirty:
                # If the given function has any update to records,
                # commits them.
                session.commit()
        except Exception as e:
            # If any exception raised, rollbacks the transaction.
            LOG.error('Error in %s: %s', func.__name__, e)
            if session.dirty:
                LOG.error('Do rolling back %s table',
                          session.dirty[0].__tablename__)
                session.rollback()

        return ret

    return _wrapper
Decorator for wrapping the given function in order to manipulate (CRUD)
    the records safely.

    For the adding/updating/deleting records function, this decorator
    invokes "Session.commit()" after the given function.
    If any exception while modifying records raised, this decorator invokes
    "Session.rollbacks()".