Opened 10 years ago
Last modified 10 years ago
#24642 closed Bug
If queryset has orderby before distinct query selects the orderby — at Initial Version
Reported by: | Esteban F. | Owned by: | nobody |
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Component: | Database layer (models, ORM) | Version: | 1.7 |
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
If you generate a query set like:
orders = Order.objects.filter( date = paramDate, objfilter = paramObjfilter ).order_by( 'date' )
dudes = orders.values('dude').distinct().exclude(dudeisnull = True)
Query will be:
SELECT DISTINCT "base_ordentrabajo"."dude_id", "base_orders"."date" FROM "base_orders" WHERE ...
If you remove order_by and make distinct after query is quite different (and like should be)
orders = Order.objects.filter( date = paramDate, objfilter = paramObjfilter )
dudes = orders.values('dude').distinct().exclude(dudeisnull = True)
SELECT DISTINCT "base_ordentrabajo"."dude_id" FROM "base_orders" WHERE ...
So i can't make an order_by if i need to make a distinct first. Anyway django should warn of query.order_by or don't allow to make a subset query filter with distinct if you order in the first place because this lead to unexpected results on query (query will contain not distinct values for the field you are searching for because it adds the order_by field value to the query)