Opened 21 months ago
Closed 21 months ago
#34354 closed New feature (duplicate)
models. Manager annotate() queryset conflict with models.Model
Reported by: | David Pratten | Owned by: | nobody |
---|---|---|---|
Component: | contrib.admin | Version: | 4.1 |
Severity: | Normal | Keywords: | Possible |
Cc: | Triage Stage: | Unreviewed | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
With
class MyPapersManager(models.Manager): def get_queryset(self): return super().get_queryset().annotate(count_of_keywords=Coalesce(Count('keywordspapers'),0)) # .filter(in_scope=True) works fine here
class MyPapers(models.Model): objects = MyPapersManager() count_of_keywords = models.IntegerField() # generated by manager above! keywordspapers = models.ManyToManyField(to='Keywords', blank=True)
and
class MyPapersAdmin(admin.ModelAdmin): list_display = ("count_of_keywords",)
Results in runtime error The annotation 'count_of_keywords' conflicts with a field on the model.
However, f I remove the count_of_keywords
field from the models.Model I get a start up error: <class 'literature.admin.MyPapersAdmin'>: (admin.E108) The value of 'list_display[3]' refers to 'count_of_keywords', which is not a callable, an attribute of 'MyPapersAdmin', or an attribute or method on 'literature.MyPapers'.
What is the correct way to add a computed field to a model in Admin land?
Thanks
David
Change History (1)
comment:1 by , 21 months ago
Resolution: | → duplicate |
---|---|
Status: | new → closed |
Summary: | Behaviour by design? models. Manager annotate() queryset conflict with models.Model → models. Manager annotate() queryset conflict with models.Model |
Type: | Bug → New feature |
You cannot add a field based on an annotation to the model as
models.IntegerField()
. As far using annotations inlist_display
there are open tickets for that so marking as a duplicate, see #14336 and #27229.The answer is in the error message: "which is not a callable, an attribute of 'MyPapersAdmin', or an attribute or method on 'literature.MyPapers'."