<human>:  How do I implement a null coalescing operator in SQLAlchemy?
<bot>: Here is some code to query all data from table `Task` where the value of column `time_spent` is bigger than 3 hours

session.query(Task).filter(Task.time_spent > timedelta(hours=3)).all()

#Warning: this code generation is experimental. Please inspect the code for any bugs before executing.