SQLALCHEMY：如何在flask_sqlalChemy-SQLalChemy中使用@events.listens_for

问题描述

我需要一些帮助来自动执行sqlalChemical中的某些任务。 当一个新用户在我的网站上注册时，我需要添加5个人员。

我想使用sqlalChemicalevents，因为如果我能让它正常工作，以后其他自动化就会派上用场。

我正在学习Miguel Grinberg先生关于如何制作烧瓶的教程 应用程序和定义我的模型(db.Model Not Base)。

我读到要使用@event.listens_for(User.__table__, "after_insert")，我必须使用声明性基础。有什么办法可以绕过这件事吗？我的模型结构涉及近15个表！

  class User(db.Model):
        __tablename__ = "user"
        id = db.Column(db.Integer, primary_key=True, autoincrement=True)
        email = db.Column(db.String(64), unique=True, index=True)
        username = db.Column(db.String(64), unique=True, index=True)
        password_hash = db.Column(db.String(128))
        store = db.relationship('Store', uselist=False, backref="user")



@event.listens_for(User.__table__, "after_insert")
def add_personnel(*args, **kwargs):
    for i in range(5):
        db.session.add(Personnel,store_id = User.query.last().id)
    db.session.commit()
    return None

class Personnel(db.Model):
    __tablename__ = "personnel"
    id = db.Column(db.Integer, primary_key=True)
    store_id = db.Column(db.Integer, db.ForeignKey('store.id'))
    first_name = db.Column(db.String(64))
    last_name = db.Column(db.String(64))
    username = db.Column(db.String(64))
    cell_phone = db.Column(db.Integer)
    pin_number = db.Column(db.Integer)
    email = db.Column(db.String(64))
    orders = db.relationship("Order", backref='personnel', lazy='dynamic')

**TRACEBACK**



    Traceback (most recent 
    call last):
      File "manage.py", line 3, in <module>
        from app.models import User
      File "/home/#######/PycharmProjects/#######/app/models.py", line 62, in <module>
        @event.listens_for(User.__table__, "after_insert")
      File "/home/#######/PycharmProjects/#######//venv/local/lib/python2.7/site-packages/sqlalchemy/event/api.py", line 124, in decorate
        listen(target, identifier, fn, *args, **kw)
      File "/home/#######/PycharmProjects/#######/venv/local/lib/python2.7/site-packages/sqlalchemy/event/api.py", line 89, in listen
        _event_key(target, identifier, fn).listen(*args, **kw)
      File "/home/#######/PycharmProjects/#######/venv/local/lib/python2.7/site-packages/sqlalchemy/event/registry.py", line 194, in listen
        dispatch_collection = getattr(target.dispatch, identifier)
      File "/home/#######/PycharmProjects/#######/venv/local/lib/python2.7/site-packages/sqlalchemy/event/base.py", line 95, in __getattr__
        raise AttributeError(name)
    AttributeError: after_insert

---

解决方案

我使用参数中的连接使我像这样工作。

@db.event.listens_for(Order, "after_insert")
def insert_order_to_printer(mapper, connection, target):
    po = PrinterOrder.__table__
    connection.execute(po.insert().values(store_id=target.store_id, order_id=target.id, scenario=target.order_type))

其中订单为：

class Order(db.Model):
    #stuff