Opened 3 weeks ago
Last modified 11 days ago
#37350 closed Bug
distinct(*fields) does not fathom aliases containing the lookup separator: "__" — at Initial Version
| Reported by: | Jacob Walls | Owned by: | Django Sprints |
|---|---|---|---|
| Component: | Database layer (models, ORM) | Version: | dev |
| Severity: | Normal | Keywords: | |
| Cc: | Triage Stage: | Ready for checkin | |
| Has patch: | yes | Needs documentation: | no |
| Needs tests: | no | Patch needs improvement: | no |
| Easy pickings: | no | UI/UX: | no |
Description
We are gradually improving the situation with respect to the treatment of annotation aliases containing the lookup separator, see PR discussion. This ticket is for .distinct(*fields).
When an alias is provided to .distinct(*fields), is it split on LOOKUP_SEP before checking against the alias map, meaning it will miss an alias that contains it.
Reproducer:
qs = Person.objects.annotate(my__val=models.Value(1)).distinct("my__val") print(qs)
File "/django-ref/django/db/models/sql/query.py", line 1854, in names_to_path
raise FieldError(
django.core.exceptions.FieldError: Cannot resolve keyword 'my' into field. Choices are: id, my__val, name
The helper from 73cc09f14f13fedddc14d6ba5b287cb33c24e4a4 could be used as part of fixing this, so that we don't omit any nuance with FilteredRelation.
Using the lookup separator in an annotation alias sounds a little unorthodox, but it's present in the default alias generated by .aggregate(), and we've taken reports on it before. Also, if you let users choose aliases in configurable reports, it's bound to come up, and we've taken issues on that.