テスト用のDBコネクションをいじってしまってて素直にTransactionTestCase.assertNumQueriesが使えない場合に。

# coding: utf-8

import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "project.settings")

from django.conf import settings
from django.db import connections

import unittest, pprint
from collections import deque
from core.models import Kvs, Hoge


class TestKvs(unittest.TestCase):

    def setUp(self):
        settings.DEBUG = True

    def tearDown(self):
        # django.db. reset_queries でもいい
        connections['default'].queries_log = deque()  
        settings.DEBUG = False

    def test_simple(self):
        hoge = list(Hoge.objects.all())[0]
        # select
        self.assertEqual(len(connections['default'].queries), 1)

        Kvs.set(hoge.id, hoge)
        # select, begin, update
        self.assertEqual(len(connections['default'].queries), 4)

        got = Kvs.get(hoge.id)
        # select
        self.assertEqual(got.id, hoge.id)
        self.assertEqual(len(connections['default'].queries), 5)


if __name__ == "__main__":
    unittest.main()

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