标签:情况 ted pen origin django manual not fir 写法
https://docs.djangoproject.com/en/3.0/topics/db/transactions/
You may need to manually revert model state when rolling back a transaction.
The values of a model’s fields won’t be reverted when a transaction rollback happens. This could lead to an inconsistent model state unless you manually restore the original field values.
For example, given MyModel
with an active
field, this snippet ensures that the ifobj.active
check at the end uses the correct value if updating active
to True
fails in the transaction:
from django.db import DatabaseError, transaction
obj = MyModel(active=False)
obj.active = True
try:
with transaction.atomic():
obj.save()
except DatabaseError:
obj.active = False
if obj.active:
...
id 不连续
User.objects.get(x=y)注意这种写法 当且仅当需要x=y的情况下才不会抛异常 exception ;raise ParamError(CustomerError.X_NOT_EXIST)
可以使得事务回滚;但是 不raise error 不会使得事务回滚。
回滚 导致 自增id不连续。
标签:情况 ted pen origin django manual not fir 写法
原文地址:https://www.cnblogs.com/yuanjiangw/p/12776499.html