Opened 9 years ago
Last modified 8 years ago
#26638 closed New feature
Allow callable in defaults argument for QuerySet.get_or_create — at Initial Version
Reported by: | Maxime Lorant | Owned by: | nobody |
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Component: | Database layer (models, ORM) | Version: | dev |
Severity: | Normal | Keywords: | |
Cc: | Will Koster | Triage Stage: | Accepted |
Has patch: | yes | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | yes |
Easy pickings: | yes | UI/UX: | no |
Description
It would be nice if get_or_create
handles callable in the defaults
parameter so the defaults value are not computed at each selection. Indeed, if your default values for insertion contains selection of related object or any long computation, it is done at each call, even if the object can be retrieved without insertion (and so the defaults parameter is not used).
In term of code, I would like to do something like this:
SomeObject.objects.get_or_create( key1=value1, key2=value2, defaults={ 'key3': long_processing_to_get_default(), # or even 'key3': lambda: OtherModel.objects.get(pk=request.some_value) } )
For backward-compatibility and ease of writing, it should still accept values that are not callables. See the patch attached (unit tests are missing so it is not complete!)