Django: is there a way to count SQL queries from an unit test?

Question

I am trying to find out the number of queries executed by a utility function. I have written a unit test for this function and the function is working well. What I would like to

Answer 1

If you have DEBUG set to True in your settings.py (presumably so in your test environment) then you can count queries executed in your test as follows:

from django.db import connection

class DoSomethingTests(django.test.TestCase):
    def test_something_or_other(self):
        num_queries_old = len(connection.queries)
        do_something_in_the_database()
        num_queries_new = len(connection.queries)
        self.assertEqual(n, num_queries_new - num_queries_old)

Answer 2

If you are using pytest, pytest-django has django_assert_num_queries fixture for this purpose:

def test_queries(django_assert_num_queries):
    with django_assert_num_queries(3):
        Item.objects.create('foo')
        Item.objects.create('bar')
        Item.objects.create('baz')