Opened 14 years ago
Last modified 13 years ago
#16173 closed Cleanup/optimization
manager.get on foreign key fields (related fields) — at Version 1
Reported by: | Owned by: | nobody | |
---|---|---|---|
Component: | Database layer (models, ORM) | Version: | dev |
Severity: | Normal | Keywords: | manager foreignkey |
Cc: | fhahn | Triage Stage: | Accepted |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | yes |
Easy pickings: | yes | UI/UX: | no |
Description (last modified by )
__get__
on ForeignKey field uses manager to query the values.
The code is as given below:
# If the related manager indicates that it should be used for # related fields, respect that. rel_mgr = self.field.rel.to._default_manager db = router.db_for_read(self.field.rel.to, instance=instance) if getattr(rel_mgr, 'use_for_related_fields', False): rel_obj = rel_mgr.using(db).get(**params)
Check the last line rel_obj = rel_mgr.using(db).get(**params)
for using rel_mgr
with multiple databases. rel_mgr.using(db)
returns a queryset. If developer has written a custom manager class for which get
is overriden, then custom managers get
function will never get called. This results in surprises to the developer. I think this line should changed to:
rel_obj = rel_mgr.db_manager(db).get(**params)
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