#2820 closed enhancement (wontfix)
selected_related not pulling from GenericRelation's
Reported by: | anonymous | Owned by: | Adrian Holovaty |
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Component: | Core (Other) | Version: | dev |
Severity: | normal | Keywords: | |
Cc: | Triage Stage: | Unreviewed | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
My assumption is that select_related would pull a GenericRelation but it doesn't seem to.
The problem comes from where I have two models, one being generic, and one being specific. The generic model holds data thats used by several models, and contains an object_id and content_type.
The specific model let's call it Article, and the generic Rating. The end goal would be to be able to do things, such as create a manager, which could perform a left join. The code in SQL would be similar to select * from article_table left join rating_table on a.id = b.object_id and b.content_type_id = x.
The problem is (as far as I can tell) there's no way to do this in django.
Change History (4)
comment:1 by , 18 years ago
comment:2 by , 18 years ago
Resolution: | → wontfix |
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Status: | new → closed |
I'm completely fine with saying "It doesn't intend to do that." Generic relations are such a special case that it's fair to say they don't need to be able to support select_related
.
comment:3 by , 11 years ago
Easy pickings: | unset |
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UI/UX: | unset |
Generic relations are same special case as comments to any content on web-sites. So its not "special".
comment:4 by , 11 years ago
Django can actually nowadays generate the LEFT OUTER JOIN mentioned in the description. There is a more fundamental problem - GenericRelation isn't unique, you can have multiple comments per content... So, use prefetch_related().
To rephrase this a bit, the GenericRelation was the solution to the lack of a solution.