Django事务

有时数据的更新修改涉及到多张表的更改，但因为某一环节的出错导致关联数据不能同时更新，为了避免这种问题的出现，可以使用事物（transaction）来解决

Models:

from django.db import models

class UserInfo(models.Model):
    username = models.CharField(max_length=32)
    email = models.EmailField(max_length=64)

class Dept(models.Model):
    title = models.CharField(max_length=32)

Urls:

from django.conf.urls import url
from app01 import views

urlpatterns = [
    url(r'^test/$', views.test),
]

Views:

from django.shortcuts import render, HttpResponse
from . import models


def test(request):
    try:
        from django.db import transaction  # 导入事务
        with transaction.atomic():
            user_obj = models.UserInfo.objects.create(username='Lena', email='example@live.com')
            dept_obj = models.Dept.objects.create(title='IT')
    except Exception as e:
        return HttpResponse('error happened, db rollback')

    return HttpResponse('OK')

事务的应用需要数据库引擎的支持——Innodb

user_obj和dept_obj的创建需要同时完成，其中一个操作行为的出错都不会实现user_obj和dept_obj的创建