Test failures after upgrading Django app to mysqlclient 1.3.14

[edmorley]

Hi

STR:

1. Have a Django 1.11 app whose tests make use of CaptureQueriesContext, such as:
   • https://github.com/mozilla/treeherder/blob/d36bb8ab7644d3afe4b21e2b283c77e51aca1a15/tests/model/test_bugscache.py#L151-L179
2. Upgrade the mysqlclient used by that app from 1.3.13 to 1.3.14, eg:
   • Update mysqlclient to 1.3.14 mozilla/treeherder#4342
3. Run test suite (either locally or on Travis)

Expected:

No test failures after upgrading, since:

• it was a minor release
• there was no mention of removing _last_executed in the changelog

Actual:

Test failures, eg:

        with CaptureQueriesContext(connection) as context:
            Bugscache.search(search_term)
    
            search_query = get_search_query(context.captured_queries[0]['sql'])
>           assert search_query
E           AssertionError: assert ''

(https://travis-ci.org/mozilla/treeherder/jobs/463284994#L605)

Whilst Django's handling has been updated for Django 2.1+, this leaves Django 1.11 (LTS) and Django 2.0 incompatible with latest mysqlclient.

If restoring _last_executed ends up being wontfix, please can the changelog be updated to mention the removal (and if possible a reference to say Django <2.1 users should not update)?

Many thanks :-)

Refs:

• Clear cursor._executed before query() #283 (comment)
• https://code.djangoproject.com/ticket/30013
• Fixed #30013 -- Fixed DatabaseOperations.last_executed_query() with mysqlclient 1.3.14+. django/django#10726
• [2.0.x] Refs #30013 -- Doc'd that mysqlclient 1.3.14 and later isn't supported. django/django#10727

[methane]

Expected:

No test failures after upgrading, since:

• it was a minor release
• there was no mention of removing _last_executed in the changelog

When using private member, both are expected.

[edmorley]

When using private member, both are expected.

Yeah is fair :-) Thank you for the changelog update.