log all sql queries

How can I log all SQL queries that my django application performed?

I want to log everything, including SQLs from admin site. I saw this question and a FAQ answer but I still can't figure out where should I put

from django.db import connection
connection.queries

to log everything to one file?

So my question is - what should I do to have a file (say all-sql.log) where all SQL statements are logged?

Merge the following snippet with the LOGGING field in your settings.py:

LOGGING = {
    'version': 1,
    'filters': {
        'require_debug_true': {
            '()': 'django.utils.log.RequireDebugTrue',
        }
    },
    'handlers': {
        'console': {
            'level': 'DEBUG',
            'filters': ['require_debug_true'],
            'class': 'logging.StreamHandler',
        }
    },
    'loggers': {
        'django.db.backends': {
            'level': 'DEBUG',
            'handlers': ['console'],
        }
    }
}

Tweaked from @acardenas89 answer

Add the following bold statements in settings.py

if DEBUG:
import logging
l = logging.getLogger('django.db.backends')
l.setLevel(logging.DEBUG)
l.addHandler(logging.StreamHandler())

LOGGING = {
'version': 1,
'disable_existing_loggers': False,
'filters': {
'require_debug_false': {
'()': 'django.utils.log.RequireDebugFalse'
}
},
'handlers': {
'mail_admins': {
'level': 'ERROR',
'filters': ['require_debug_false'],
'class': 'django.utils.log.AdminEmailHandler'
},'console': {
'level': 'DEBUG',
'class': 'logging.StreamHandler',
},
},
'loggers': {
'django.request': {
'handlers': ['mail_admins'],
'level': 'ERROR',
'propagate': True,
},'django.db.backends.sqlite3': {
'level': 'DEBUG',
'handlers': ['console'],
},
}
}
  

Resource/Credit

Maybe check out https://github.com/django-debug-toolbar/django-debug-toolbar

It'll let you see all the queries generated by a given page. As well as stacktraces of where they occur etc.

EDIT: to log all SQL queries to a file etc, then you will want to create some middleware. Middleware gets run on every request. There are several Django snippets out there for this sort of thing:

• http://djangosnippets.org/snippets/290/
• http://djangosnippets.org/snippets/264/

Those are concerned with printing to the terminal, but it wouldn't be hard to adapt them to use python's logging library.

To log SQL queries during testing, you need two things:

1. django.db.backends logger enabled and
2. @override_settings(DEBUG=True) decorator.

Test runner will set DEBUG=False by default, ignoring what you may have set in DJANGO_SETTINGS_MODULE.

The minimum settings:

# https://docs.djangoproject.com/en/dev/ref/settings/#logging
LOGGING = {
    'version': 1,
    'handlers': {
        'console': {
            'class': 'logging.StreamHandler',
        },
    },
    'loggers': {
        'django.db.backends': {
            'level': 'DEBUG',
        },
    },
    'root': {
        'handlers': ['console'],
    }
}

The example test case:

from django.contrib.auth.models import User
from django.test import TestCase, override_settings


class UserTests(TestCase):

    # To log queries in tests you need to manually override DEBUG setting
    # because testing sets DEBUG=False by default

    @override_settings(DEBUG=True)
    def test_create_user(self):
        User.objects.create()

Django 1.3 logs all SQL statements to django.db.backends logger:

https://docs.djangoproject.com/en/dev/topics/logging/#django-db-backends

You only need:

@override_settings(DEBUG=True)

if you already have SQL debug statements being printed in runserver.

Add the decorator to your class TestA(TestCase) or test_function:

@override_settings(DEBUG=True)
class TestA(TestCase):
...

    @override_settings(DEBUG=True)
    def test_function(self):
    ...

Credits to @Janusz Skonieczny's answer!

You need to put this in a middleware package. The middleware sits between the webserver/django core and all your views. It can do preprocessing before the request, and postprocessing after the request completed. For example, save the queries to a file.