middleware.py

from django.db import connection
from django.utils.log import getLogger

logger = getLogger(__name__)

class QueryCountDebugMiddleware(object):
    """
    This middleware will log the number of queries run
    and the total time taken for each request (with a
    status code of 200). It does not currently support
    multi-db setups.
    """
    def process_response(self, request, response):
        if response.status_code == 200:
            total_time = 0

            for query in connection.queries:
                query_time = query.get('time')
                if query_time is None:
                    # django-debug-toolbar monkeypatches the connection
                    # cursor wrapper and adds extra information in each
                    # item in connection.queries. The query time is stored
                    # under the key "duration" rather than "time" and is
                    # in milliseconds, not seconds.
                    query_time = query.get('duration', 0) / 1000
                total_time += float(query_time)

            logger.debug('%s queries run, total %s seconds' % (len(connection.queries), total_time))
        return response

settings.py

# Should be the first item in MIDDLEWARE_CLASSES.
# Only works in development.
# Try something like this in your settings.py:

if DEBUG:
    MIDDLEWARE_CLASSES = ('path.to.middleware.QueryCountDebugMiddleware',) + MIDDLEWARE_CLASSES