Discover possible N+1 queries in Django ORM at runtime during development
The objective of this library is to help you discover any N+1s in your code at development time. Enable logging of warnings by following instructions shown in Usage section. Run your Django app as usual and you will see warning logs of any possible N+1s if found.
Install the package from PyPI using pip as following
pip install django_nplusone
Once package is installed, you can register the package in your settings.py as:
import nplusone
if DEBUG:
nplusone.show_nplusones()
This should start logging possible N+1s warnings using your logger configuration. The library uses standard python
logging module and uses logger by the name of nplusone.
You can ignore warning for a specific statement by ending the statement with # NO-NPLUSONE.
You can test the N+1 warning logging by putting some code as shown below somewhere in your application code that you
know will get executed. Say you have a model User with a foreign key field org to Organization model.
user = User.objects.all()[0]
print(user.org)
You should see a log message with a message that looks like this:
... Possible N+1 for model: User, field: org, relationship: ForwardManyToOne, file: <?>, function: <?>, line: <?>, statement: <?>
where <?> will have correct values for the fields derived from call stack pointing you to the statement that has
possible N+1