使对象实例成为 瞬态之后， 您必须 删除 其对象ID。如果没有对象标识，则可以将其再次添加到数据库中，数据库将为其生成新的对象标识。
if __name__ == '__main__': # the persistent object with an identiy in the database obj = GetOneMachineDataFromDatabase() # make it transient make_transient(obj) # remove the identiy / object-id obj._oid = None # adding the object again generates a new identiy / object-id _session.add(obj) # this include a flush() and create a new primary key _session.commit()
