Fields annotated for filtering which are not included in values are included in GROUP BY clause in SQL

[mitchelljkotler]

I am running a complex query, which annotates certain fields solely to filter on them. They are not included in a call to values. Another annotation is included, but it is incorrect due to the previous annotations being included in the GROUP BY clause.

Here is a not so simple example:

# We are filtering on the journey date, using the datediff function
# We annotate the reported tds fields, since we need two aliases of them for the different filterings applied

print EpTag.objects.filter(statuschanges__status=attached)\
    .annotate(attach_date=F('statuschanges__reported_tds'))\
    .filter(statuschanges__status=detached)\
    .annotate(detach_date=F('statuschanges__reported_tds'))\
    .annotate(journey_days=Func(F('detach_date'), F('attach_date'), function='DATEDIFF', output_field=IntegerField()))\
    .filter(journey_days__lt=10)\
    .annotate(name=F('object__producer__name'))\
    .values('object__producer', 'name')\
    .annotate(count=Count('pk', distinct=True))\
    .order_by().query

SELECT `ep_object`.`cid`, `ep_entity`.`name` AS `name`, COUNT(DISTINCT `ep_tag`.`tid`) AS `count`
FROM `ep_tag`
INNER JOIN `ep_statuschange` ON ( `ep_tag`.`tid` = `ep_statuschange`.`tid` )
INNER JOIN `ep_statuschange` T4 ON ( `ep_tag`.`tid` = T4.`tid` )
LEFT OUTER JOIN `ep_object` ON ( `ep_tag`.`oid` = `ep_object`.`oid` )
LEFT OUTER JOIN `ep_entity` ON ( `ep_object`.`cid` = `ep_entity`.`eid` )
WHERE (`ep_statuschange`.`statusid` = 201 AND T4.`statusid` = 1000 AND DATEDIFF(T4.`reported_tds`, `ep_statuschange`.`reported_tds`) < 10)
# Group by still includes reported_tds and DATEDIFF fields, even though they were not selected.  This breaks my count
GROUP BY `ep_object`.`cid`, `ep_statuschange`.`reported_tds`, T4.`reported_tds`, DATEDIFF(T4.`reported_tds`, `ep_statuschange`.`reported_tds`), `ep_entity`.`name` ORDER BY NULL

In django/db/models/sql/query.py, line 1751 - all annotations are included in the group by. I believe this should be using annotation_select instead of annotations.