django how to see sql query when running tests?

If you want to print/log all SQL queries from the tests, try subclassing TestCase like this:

from django.conf import settingsfrom django.template import Template, Contextimport sysfrom django.db import connectionfrom django.test import TestCaseclass LoggingTestCase(TestCase):  @staticmethod  def setUpClass():    # The test runner sets DEBUG to False. Set to True to enable SQL logging.    settings.DEBUG = True    super(LoggingTestCase, LoggingTestCase).setUpClass()  @staticmethod  def tearDownClass():    super(LoggingTestCase, LoggingTestCase).tearDownClass()    time = sum([float(q['time']) for q in connection.queries])    t = Template("{{count}} quer{{count|pluralize:\"y,ies\"}} in {{time}} seconds:\n\n{% for sql in sqllog %}[{{forloop.counter}}] {{sql.time}}s: {{sql.sql|safe}}{% if not forloop.last %}\n\n{% endif %}{% endfor %}")    print >> sys.stderr, t.render(Context({'sqllog': connection.queries, 'count': len(connection.queries), 'time': time}))    # Empty the query list between TestCases.        connection.queries = []

Then use LoggingTestCase instead of TestCase as the base class in your tests. Just remember to call this tearDownClass if you override it.

Another option is to use CaptureQueriesContext (tested with pytest).

from django.db import connectionfrom django.test.utils import CaptureQueriesContextdef test_foo():    with CaptureQueriesContext(connection) as ctx:        # code that runs SQL queries        print(ctx.captured_queries)

Sources:

• https://blog.ploetzli.ch/2019/showing-sql-queries-with-pytest-and-django/
• How to force django to print each executed sql query

You can also do the following to get the queries (and then for instance print it or evaluate it in your test).

Actually you shouldn't alter django.conf.settings nowadays, therefore I use override_settings.

from django.db import connection, reset_queriesfrom django.test import override_settings, TransactionTestCaseclass TransactionTests(TransactionTestCase):    @override_settings(DEBUG=True)    def test_sql(self):        reset_queries()        try:            # Code that uses the ORM goes here        except Exception as e:            pass        self.assertEqual(connection.queries, [])

TestCase might also be suitable, see the differences in this answer.

See the Django documentation for details for SQL output.