#28078: Can't use field as part of expression when annotate key shadows model
field
-------------------------------------+-------------------------------------
Reporter: Pavel Patrin | Owner: nobody
Type: | Status: closed
Cleanup/optimization |
Component: Database layer | Version: 1.10
(models, ORM) |
Severity: Normal | Resolution: invalid
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by Simon Charette):
* status: new => closed
* resolution: => invalid
Comment:
After further review I'm going to close this one as invalid.
If you shadow a field with an annotation (this seems to be only allowed
here because `values` is used prior see #28072) then the ORM will default
to the annotation override, `F` doesn't mean field reference it should
have been name `Ref` (and `Ref` should have been named `ResolvedRef`).
If you want to keep referring to `MyModel.amount_field_1` you must create
an alias to it prior to shadowing it with your annotation
{{{#!python
MyModel.objects.annotate(amount_field_1_alias=F("amount_field_1")).values(
"grouping_field"
).annotate(
amount_field_1=Sum("amount_field_1"),
amount_field_2=Sum(F("amount_field_1_alias") + F("amount_field_2")),
)
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/28078#comment:3>
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