Django Querycount

Inspired by this post by David Szotten, this project gives you a middleware that prints DB query counts in Django's runserver console output.

Installation

pip install django-querycount

Just add querycount.middleware.QueryCountMiddleware to your MIDDLEWARE.

Notice that django-querycount is hard coded to work only in DEBUG mode set to true

Settings

There are two possible settings for this app: The first defines threshold values used to color output, while the second allows you customize requests that will be ignored by the middleware. The default settings are:

QUERYCOUNT = {
    'THRESHOLDS': {
        'MEDIUM': 50,
        'HIGH': 200,
        'MIN_TIME_TO_LOG':0,
        'MIN_QUERY_COUNT_TO_LOG':0
    },
    'IGNORE_REQUEST_PATTERNS': [],
    'IGNORE_SQL_PATTERNS': [],
    'DISPLAY_DUPLICATES': None,
    'RESPONSE_HEADER': 'X-DjangoQueryCount-Count'
}

The QUERYCOUNT['THRESHOLDS'] settings will determine how many queries are interpreted as high or medium (and the color-coded output). In previous versions of this app, this settings was called QUERYCOUNT_THRESHOLDS and that setting is still supported.

The QUERYCOUNT['IGNORE_REQUEST_PATTERNS'] setting allows you to define a list of regexp patterns that get applied to each request's path. If there is a match, the middleware will not be applied to that request. For example, the following setting would bypass the querycount middleware for all requests to the admin:

QUERYCOUNT = {
    'IGNORE_REQUEST_PATTERNS': [r'^/admin/']
}

The QUERYCOUNT['IGNORE_SQL_PATTERNS'] setting allows you to define a list of regexp patterns that ignored to statistic sql query count. For example, the following setting would bypass the querycount middleware for django-silk sql query:

QUERYCOUNT = {
    'IGNORE_SQL_PATTERNS': [r'silk_']
}

The QUERYCOUNT['RESPONSE_HEADER'] setting allows you to define a custom response header that contains the total number of queries executed. To disable this header, the supply None as the value:

QUERYCOUNT = {
    'RESPONSE_HEADER': None
}

New in 0.4.0. The QUERYCOUNT['DISPLAY_DUPLICATES'] setting allows you to control how the most common duplicate queries are displayed. If the setting is None (the default), duplicate queries are not displayed. Otherwise, this should be an integer. For example, the following setting would always print the 5 most duplicated queries:

QUERYCOUNT = {
    'DISPLAY_DUPLICATES': 5,
}

License

This code is distributed under the terms of the MIT license.

Testing

Run python manage.py test querycount to run the tests. Note that this will modify your settings so that your project is in DEBUG mode for the duration of the querycount tests.

(side-note: this project needs better tests; for the moment, there are only smoke tests that set up the middleware and call two simple test views).

Contributing

Bug fixes and new features are welcome! Fork this project and send a Pull Request to have your work included. Be sure to add yourself to AUTHORS.rst.