Python sqlalchemy之后的级联更新”;“U更新”之后;事件
我正在尝试在模型更新后级联更新:Python sqlalchemy之后的级联更新”;“U更新”之后;事件,python,sqlalchemy,flask-sqlalchemy,Python,Sqlalchemy,Flask Sqlalchemy,我正在尝试在模型更新后级联更新: event.listens_for(Task, "after_update") def propagate_status(mapper, connection, target): object = target.object if object.is_finished(): object.status = COMPLETED 问题是我似乎无法将对象状态提交给实际的数据库。我可以看出状态确实设置了,因为我有一个连接到object.
event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
object = target.object
if object.is_finished():
object.status = COMPLETED
问题是我似乎无法将对象状态提交给实际的数据库。我可以看出状态确实设置了,因为我有一个连接到object.status的侦听器
我尝试对对象调用commit(),但结果是:
ResourceClosedError: This transaction is closed
有没有更好的方法来实现这一点?我应该直接使用连接对象吗?适用于以后发现此对象的用户。我能够直接成功地使用连接:
@event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
obj_table = Object.__table__
object = target.object
if object.is_finished():
connection.execute(
scan_table.update().
where(object_table.c.id == object.id).
values(status=COMPLETED)
)
如果有更优雅的方式,我完全赞成。对于那些后来发现这一点的人。我能够直接成功地使用连接:
@event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
obj_table = Object.__table__
object = target.object
if object.is_finished():
connection.execute(
scan_table.update().
where(object_table.c.id == object.id).
values(status=COMPLETED)
)
如果有更优雅的方式,我完全赞成。对于那些后来发现这一点的人。我能够直接成功地使用连接:
@event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
obj_table = Object.__table__
object = target.object
if object.is_finished():
connection.execute(
scan_table.update().
where(object_table.c.id == object.id).
values(status=COMPLETED)
)
如果有更优雅的方式,我完全赞成。对于那些后来发现这一点的人。我能够直接成功地使用连接:
@event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
obj_table = Object.__table__
object = target.object
if object.is_finished():
connection.execute(
scan_table.update().
where(object_table.c.id == object.id).
values(status=COMPLETED)
)
如果有更优雅的方式,我完全赞成。在更新后调用
时,会话处于刷新状态。因此,您将无法在该会话中提交任何更改。另一种方法是在更新后在事件处理程序中创建新会话
@event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
obj_table = Object.__table__
object = target.object
if object.is_finished():
session = db.create_scoped_session() # or any other way
session.query(Object).filter(Object.id == target.id).update({"status": COMPLETED})
session.commit()
更新后调用时,会话处于刷新状态。因此,您将无法在该会话中提交任何更改。另一种方法是在更新后在事件处理程序中创建新会话
@event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
obj_table = Object.__table__
object = target.object
if object.is_finished():
session = db.create_scoped_session() # or any other way
session.query(Object).filter(Object.id == target.id).update({"status": COMPLETED})
session.commit()
更新后调用时,会话处于刷新状态。因此,您将无法在该会话中提交任何更改。另一种方法是在更新后在事件处理程序中创建新会话
@event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
obj_table = Object.__table__
object = target.object
if object.is_finished():
session = db.create_scoped_session() # or any other way
session.query(Object).filter(Object.id == target.id).update({"status": COMPLETED})
session.commit()
更新后调用时,会话处于刷新状态。因此,您将无法在该会话中提交任何更改。另一种方法是在更新后在事件处理程序中创建新会话
@event.listens_for(Task, "after_update")
def propagate_status(mapper, connection, target):
obj_table = Object.__table__
object = target.object
if object.is_finished():
session = db.create_scoped_session() # or any other way
session.query(Object).filter(Object.id == target.id).update({"status": COMPLETED})
session.commit()