How to log all sql queries in Django?

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.

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

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

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

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

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()

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!

If you want to have this toggle-able by a setting, do something like the following in settings.py:

if LOG_DB_QUERIES:
    LOGGING["handlers"]["console"] = {
        "level": "DEBUG", "class": "logging.StreamHandler"
    }
    LOGGING["loggers"]["django.db.backends"] =  {
        "level": "DEBUG", "handlers": ["console"]
    }
    

Also, please note that this will only work if you have DEBUG = True in settings.py.

Thanks to @Gian Marco for the logging config that makes this work.

I don’t know how to log all SQL queries in Django to a file.

But, I know how to use the code below to get the part of the SQL queries in Django Admin. *You can also see my answer explaining how to get the part of the SQL queries in Django View:

from django.db import connection
connection.queries

For example, you can use connection.queries in overridden save_model() in Person admin to get the SQL queries as shown below:

# "store/admin.py"

from .models import Person
from django.db import connection

@admin.register(Person)
class PersonAdmin(admin.ModelAdmin):
    # Here
    def save_model(self, request, obj, form, change):
        obj.save()
        for query in connection.queries: # Here
            print(query)

Then, if you change a person as shown below:

The SQL queries are printed on console as shown below:

{'sql': 'SELECT "django_session"."session_key", "django_session"."session_data", "django_session"."expire_date" FROM "django_session" WHERE ("django_session"."expire_date" > '2022-12-24T06:47:45.799803+00:00'::timestamptz AND "django_session"."session_key" = '7spdc2c5h3g2v5hjc898eqphf11g9eck') LIMIT 21', 'time': '0.000'}
{'sql': 'SELECT "account_customuser"."id", "account_customuser"."password", "account_customuser"."last_login", "account_customuser"."is_superuser", "account_customuser"."first_name", "account_customuser"."last_name", "account_customuser"."is_staff", "account_customuser"."is_active", "account_customuser"."date_joined", "account_customuser"."email", "account_customuser"."phone", "account_customuser"."my_order" FROM "account_customuser" WHERE "account_customuser"."id" = 1 LIMIT 21', 'time': '0.000'}
{'sql': 'SELECT "store_person"."id", "store_person"."name" FROM "store_person" WHERE "store_person"."id" = 191 LIMIT 21', 'time': '0.000'}
{'sql': 'UPDATE "store_person" SET "name" = 'David' WHERE "store_person"."id" = 191', 'time': '0.000'}
[24/Dec/2022 15:47:45] "POST /admin/store/person/191/change/ HTTP/1.1" 302 0
[24/Dec/2022 15:47:46] "GET /admin/store/person/ HTTP/1.1" 200 22584
[24/Dec/2022 15:47:46] "GET /admin/jsi18n/ HTTP/1.1" 200 3195