Orm SQLAlchemy:ObjectDeletedError在提交后访问Model.id时，为什么？
它有时发生在我的产品环境上（大多数情况下是可以的）。我怀疑它是否与sessionmaker func中的参数'expire_on_commit'有关Orm SQLAlchemy:ObjectDeletedError在提交后访问Model.id时，为什么？,orm,sqlalchemy,Orm,Sqlalchemy,它有时发生在我的产品环境上（大多数情况下是可以的）。我怀疑它是否与sessionmaker func中的参数'expire_on_commit'有关 @close_session def func(): session = DBSession() # scoped_session, thread_local m = Model() m.content = 'content' session.add(m) try: session.commi
@close_session
def func():
session = DBSession() # scoped_session, thread_local
m = Model()
m.content = 'content'
session.add(m)
try:
session.commit()
except SQLAlchemyError as e:
session.rollback()
raise_my_exception()
return m.id
engines = {
'master': create_engine(
settings.MASTER_URL, echo=settings.ECHO_SQL, pool_recycle=3600),
'slave': create_engine(
settings.SLAVE_URL, echo=settings.ECHO_SQL, pool_recycle=3600),
}
class RoutingSession(Session):
def get_bind(self, mapper=None, clause=None):
#return engines['master']
if self._flushing:
return engines['master']
else:
return engines['slave']
DBSession = scoped_session(sessionmaker(class_=RoutingSession))
class ObjectDeletedError(sqlalchemy.exc.InvalidRequestError)
| A refresh operation failed to retrieve the database
| row corresponding to an object's known primary key identity.
|
| A refresh operation proceeds when an expired attribute is
| accessed on an object, or when :meth:`.Query.get` is
| used to retrieve an object which is, upon retrieval, detected
| as expired. A SELECT is emitted for the target row
| based on primary key; if no row is returned, this
| exception is raised.
|
| The true meaning of this exception is simply that
| no row exists for the primary key identifier associated
| with a persistent object. The row may have been
| deleted, or in some cases the primary key updated
| to a new value, outside of the ORM's management of the target
| object.
|
编辑： 我将“return m.id”放在“session.commit（）”之后，仍然会引发ObjectDeletedEror
@close_session
def func():
session = DBSession() # scoped_session, thread_local
m = Model()
m.content = 'content'
session.add(m)
try:
session.commit()
return m.id
except SQLAlchemyError as e:
session.rollback()
raise_my_exception()
编辑2： 我将RoutingSession更改为仅返回master，错误消失了：
class RoutingSession(Session):
def get_bind(self, mapper=None, clause=None):
return engines['master']
你知道怎么解决吗？这个错误意味着两件事之一：
DBSession是使用默认值创建的（expire\u on\u commit=True）。因此，在提交之后，当返回obj.id时，obj已过期。所以会话将从从数据库（引擎['slave']）获取obj，但由于主从延迟，相应的记录尚未同步到slave 请包括您的生产和开发环境的所有sqlalchemy配置。“在提交时过期”似乎是一个可能的违规者，但我们如何知道您使用了什么？我已经给出了配置。在pro和dev环境中都是一样的。raise_my_exception（）确实引发了异常。2.
DBSession（）Edit2