title: How should I use Django-setting ATOMIC_REQUESTS? It doesn't work as I expected
body: <p>macOS, Django 1.11, mysql 5.7,</p>
  
  <p>I want to know how <code>ATOMIC_REQUESTS</code> worked, how can I use it.</p>
  
  <pre class="lang-py prettyprint-override"><code># some code in settings.py
  
  DATABASES = {
      'default': {
          'ENGINE': 'django.db.backends.mysql',
          'HOST': '127.0.0.1',
          'NAME': 'kma_dev',
          'USER': 'root',
          'PASSWORD': 'root',
          'ATOMIC_REQUEST': True,
      }
  }
  </code></pre>
  
  <p>When I raise an Error in view, mysql operation didn't roll back.</p>
  
  <pre><code># test raise Error in view like this⬇️⬇️
  
  
  class StoreGroup(View):
  
      def get(self, request):
          s = Store.objects.first()
          s.name = s.name + 'ABC'
          s.save()
          raise ValueError
  </code></pre>
  
  <p>Thanks very much.</p>