Question

考虑以下一对多模型。

class Person(Base):
    id
    things = relationship('Thing')

    def some_magic_here():
        pass
class Thing(Base):
    id
    person_id = ForeignKey(person.id)

我想要实现的是，当我执行以下操作时：

p = Person()
thing1 = Thing()
thing2 = Thing()
p.things = [thing1, thing2]

方法some_magic_here将在作为子项添加之前执行一些处理thing1和thing2的工作

Answer 1

您想要事件系统：http://docs.sqlalchemy.org/en/latest/orm/events.html#sqlalchemy.orm.events.AttributeEvents.append

e.g。类似的东西：

@listens_for(Person.things, 'append')
def some_magic_here(target, value, initiator):
    # do whatever

孩子们定下来怎么办？

1 个答案: