Opened 10 years ago

Last modified 10 years ago

#11541 new Bug

F() expressions don't allow assignment of Foreign Key values on instances

Reported by: Russell Keith-Magee Owned by: nobody
Component: Database layer (models, ORM) Version: 1.1-beta
Severity: Normal Keywords:
Cc: Triage Stage: Accepted
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no


Lines 93-102 of the expressions model test define the following test case:

# F expressions cannot be used to update attributes which are foreign keys, or
# attributes which involve joins.
>>> test_gmbh.point_of_contact = None
>>> test_gmbh.point_of_contact is None
>>> test_gmbh.point_of_contact = F('ceo')
Traceback (most recent call last):
ValueError: Cannot assign "<django.db.models.expressions.F object at ...>": "Company.point_of_contact" must be a "Employee" instance.

There's no reason this sort of assignment shouldn't be possible - it just requires the appropriate handling on the related field.

Change History (5)

comment:1 Changed 10 years ago by Russell Keith-Magee

Triage Stage: UnreviewedAccepted
Version: 1.01.1-beta-1

comment:2 Changed 10 years ago by dc

Saving FileField and ImageField with assigned F expression will also fail with

AttributeError: 'F' object has no attribute 'field'

comment:3 Changed 8 years ago by Julien Phalip

Severity: Normal
Type: Bug

comment:4 Changed 7 years ago by Aymeric Augustin

UI/UX: unset

Change UI/UX from NULL to False.

comment:5 Changed 7 years ago by Aymeric Augustin

Easy pickings: unset

Change Easy pickings from NULL to False.

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