python - SQL炼金术 : AttributeError: type object 'events' has no attribute 'query'

Question

我正在尝试删除数据库中已经发生的事件。我的脚本如下。

在**的那一行，我得到一个错误

AttributeError: type object 'events' has no attribute 'query'

有人知道怎么解决吗？谢谢!

Base = automap_base()

# engine, suppose it has two tables 'user' and 'address' set up
engine = create_engine("DB_URL")

# reflect the tables
Base.prepare(engine, reflect=True)

# mapped classes are now created with names by default
# matching that of the table name.
Event = Base.classes.events
User = Base.classes.users

**events = Event.query.filter(end_time < datetime.now())**
session = Session(engine)
session.delete(events)
session.commit()

Answer 1

您不在映射类上调用 query()，而是在 session 对象上调用 query():

Base = automap_base()

# engine, suppose it has two tables 'user' and 'address' set up
engine = create_engine("DB_URL")

# reflect the tables
Base.prepare(engine, reflect=True)

# mapped classes are now created with names by default
# matching that of the table name.
Event = Base.classes.events
User = Base.classes.users

session = Session(engine)
selected_events = session.query(Event).filter(Event.end_time < datatime.now())
selected_events.delete()
session.commit()