Opened 4 years ago
Closed 4 years ago
#32573 closed Bug (fixed)
Query optimization in YearLookup breaks filtering by "__iso_year"
Reported by: | Florian Demmer | Owned by: | Florian Demmer |
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Component: | Database layer (models, ORM) | Version: | 2.2 |
Severity: | Normal | Keywords: | |
Cc: | Sigurd Ljødal | Triage Stage: | Ready for checkin |
Has patch: | yes | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description (last modified by )
The optimization to use BETWEEN instead of the EXTRACT operation in YearLookup is also registered for the "__iso_year" lookup, which breaks the functionality provided by ExtractIsoYear when used via the lookup.
This has unfortunately been broken ever since ExtractIsoYear was introduced in Django 2.2 via #28649 and wasn't easy to track down since ExtractIsoYear when used by itself eg. in an annotation works perfectly fine. Just when using the lookup in a filter, the optimization is used (even when explicitly using an annotation):
# annotation works >>> qs = DTModel.objects.annotate(extracted=ExtractIsoYear('start_date')).only('id') >>> print(qs.query) SELECT "db_functions_dtmodel"."id", EXTRACT('isoyear' FROM "db_functions_dtmodel"."start_date") AS "extracted" FROM "db_functions_dtmodel" # explicit annotation used in filter does not use "extracted" and adds BETWEEN >>> print(qs.filter(extracted=2020).query) SELECT "db_functions_dtmodel"."id", EXTRACT('isoyear' FROM "db_functions_dtmodel"."start_date") AS "extracted" FROM "db_functions_dtmodel" WHERE "db_functions_dtmodel"."start_date" BETWEEN 2020-01-01 AND 2020-12-31 # implicit lookup uses BETWEEN >>> print(DTModel.objects.filter(start_date__iso_year=2020).only('id').query) SELECT "db_functions_dtmodel"."id" FROM "db_functions_dtmodel" WHERE "db_functions_dtmodel"."start_date" BETWEEN 2020-01-01 AND 2020-12-31
This results in the wrong data being returned by filters using iso_year.
This PR fixes the behaviour, reverts the invalid changes to the tests and extends one test to catch this problem: https://github.com/django/django/pull/14157
Change History (7)
comment:1 by , 4 years ago
Description: | modified (diff) |
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Has patch: | set |
Owner: | changed from | to
Status: | new → assigned |
comment:2 by , 4 years ago
Description: | modified (diff) |
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comment:3 by , 4 years ago
Patch needs improvement: | set |
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Triage Stage: | Unreviewed → Accepted |
comment:4 by , 4 years ago
Cc: | added |
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comment:6 by , 4 years ago
Triage Stage: | Accepted → Ready for checkin |
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Thanks for the report. I think we can preserve an optimization but for different boundaries. We can use .fromisocalendar() (available in Python 3.8+).