#28560: distinct() on ordered queryset with restricted list of columns returns
incorrect result
-------------------------------------+-------------------------------------
Reporter: Mariusz Felisiak | Owner: (none)
Type: Bug | Status: new
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: distinct values | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Description changed by Tobias McNulty:
Old description:
> When `distinct()` is used with `values()` (or `values_list()`) on ordered
> queryset and a list of fields in `values()` doesn't contain all fields
> from `ORDER BY`, then it doesn't return correct result because columns
> from `ORDER BY` clause must be included in `SELECT`. As Simon suggested
> we should wrap a query in a subquery (see related tickets #7070, #5321).
New description:
When `distinct()` is used with `values()` (or `values_list()`) on ordered
queryset and a list of fields in `values()` doesn't contain all fields
from `ORDER BY`, then it doesn't return correct result because columns
from `ORDER BY` clause must be included in `SELECT`.
After some discussion on the mailing list (https://groups.google.com/g
/django-developers/c/DNVRFqVBsfk/m/xDUvaq3DAAAJ) it looks like the
consensus is to require an explicit opt-in or raise an error (i.e., never
add a column implicitly if the user specified a list of columns via
values() or values_list()).
--
--
Ticket URL: <https://code.djangoproject.com/ticket/28560#comment:15>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/065.d7d01499a8fce4598fe6ca326a58dfdd%40djangoproject.com.
