Get Started with Django MongoDB Extensions

Install Django MongoDB Extensions.

Run the following command to install Django MongoDB Extensions:

pip install django-mongodb-extensions

Add Django MongoDB Extensions to your installed apps.

Navigate to your project's settings.py file and add "django_mongodb_extensions" to the INSTALLED_APPS setting, as shown in the following example:

INSTALLED_APPS = [
    'django_mongodb_extensions',
    # ... your other apps
]

Register the MQL panel.

By default, the Django Debug Toolbar works without requiring a DEBUG_TOOLBAR_PANELS setting. However, because MongoDB doesn't use SQL, the most common configuration for MongoDB applications is to replace the SQL panel with the MQL panel. Add the following setting to your settings.py file, which sets DEBUG_TOOLBAR_PANELS to the default values but replaces SQLPanel with MQLPanel:

DEBUG_TOOLBAR_PANELS = [
    'debug_toolbar.panels.history.HistoryPanel',
    'debug_toolbar.panels.versions.VersionsPanel',
    'debug_toolbar.panels.timer.TimerPanel',
    'debug_toolbar.panels.settings.SettingsPanel',
    'debug_toolbar.panels.headers.HeadersPanel',
    'debug_toolbar.panels.request.RequestPanel',
    'django_mongodb_extensions.mql_panel.MQLPanel',
    'debug_toolbar.panels.staticfiles.StaticFilesPanel',
    'debug_toolbar.panels.templates.TemplatesPanel',
    'debug_toolbar.panels.alerts.AlertsPanel',
    'debug_toolbar.panels.cache.CachePanel',
    'debug_toolbar.panels.signals.SignalsPanel',
    'debug_toolbar.panels.community.CommunityPanel',
    'debug_toolbar.panels.redirects.RedirectsPanel',
    'debug_toolbar.panels.profiling.ProfilingPanel',
]

Verify the MQL panel.

Start your development server by running the following command:

python manage.py runserver

Navigate to any page in your application that queries MongoDB. Open the Django Debug Toolbar and select the MQL panel to view the MongoDB queries executed during the request, including their execution times and explain plans.

View sample_mflix.movies query information.

If you configure Django MongoDB Extensions for the application created in the Get Started with Django MongoDB Backend tutorial, you can navigate to http://127.0.0.1:8000/recent_movies/ to view MongoDB queries executed during the request.

The Django Debug Toolbar appears at the right side of the page. Select the MQL label to view the MongoDB query used to display the recent movies, which resembles the following code:

db.movies.aggregate([{'$addFields': {'released': '$released'}}, {'$sort': SON([('released', -1)])}, {'$limit': 5}])

Then, you can explore the query information by clicking on the following buttons:

1. Select the + button to the left of the query to view the traceback, which resembles the following code:

   /path/to/site-packages/django/contrib/staticfiles/handlers.py in __call__(80)
      return self.application(environ, start_response)
   /path/to/djangoquickstart/sample_mflix/views.py in recent_movies(11)
      return render(request, "recent_movies.html", {"movies": movies})
   /path/to/site-packages/django/shortcuts.py in render(25)
      content = loader.render_to_string(template_name, context, request, using=using)
   ...

2. Select the Query button to the right of the query, in the ACTION column, to view the pretty-printed MQL. This MQL resembles the following code:

   db.movies.aggregate(
   [
      {
         "$addFields": {
               "released": "$released"
         }
      },
      {
         "$sort": {
               "released": -1
         }
      },
      {
         "$limit": 5
      }
   ]
   )

3. Select the Explain button to the right of the query, in the ACTION column, to view the explain plan for the query. This plan resembles the following code:

   {
      "explainVersion": "1",
      "stages": [
         {
               "$cursor": {
                  "queryPlanner": {
                     ...
                  },
                  "executionStats": {
                     ...
                  }
               },
               "nReturned": 21351,
               "executionTimeMillisEstimate": 59
         },
         {
               "$addFields": {
                  "released": "$released"
               },
               "nReturned": 21351,
               "executionTimeMillisEstimate": 70
         },
         {
               "$sort": {
                  "sortKey": {
                     "released": -1
                  },
                  "limit": 5
               },
               ...
         }
      ],
      ...
   }