#31581: Queryset bug when using Q()? -- doubles up the counts by doing an extra join -------------------------------------+------------------------------------- Reporter: Javier Buzzi | Owner: nobody Type: Bug | Status: new Component: Database layer | Version: 3.0 (models, ORM) | Severity: Normal | Resolution: Keywords: | Triage Stage: | Unreviewed Has patch: 0 | Needs documentation: 0 Needs tests: 0 | Patch needs improvement: 0 Easy pickings: 0 | UI/UX: 0 -------------------------------------+------------------------------------- Description changed by Javier Buzzi:
Old description: > I ran this on all the "recent" versions of python and i see the issue on > all of them. At this point, im not 100% sure if it is a problem or not, i > ran across this trying to show some counts in the Admin that had some > search_fields that traversed the model backwards and forwards in order to > match the thing properly. > > This is my mocked models of the issue: > > {{{ > class ModelA(models.Model): > somecriteria = models.CharField(max_length=50) > > class ModelC(models.Model): > unimportant = models.CharField(max_length=50) > > class ModelB(models.Model): > somerelation = models.ForeignKey(ModelA, on_delete=models.CASCADE) > m2m = models.ManyToManyField( > ModelC, > through='ModelBC' > ) > > class ModelBC(models.Model): > b = models.ForeignKey(ModelB, on_delete=models.CASCADE) > c = models.ForeignKey(ModelC, on_delete=models.CASCADE) > }}} > > The "bug" is shown when i do: > > {{{ > queryset = > ModelB.objects.select_related('a').annotate(num_c=Count('m2m__id')).values('num_c') > queryset = queryset.filter(Q(modelbc__c__unimportant='1') | > Q(somerelation__somecriteria='1')) > }}} > > When i do: > > {{{ > queryset = > ModelB.objects.select_related('a').annotate(num_c=Count('m2m__id')).values('num_c') > queryset = queryset.filter(modelbc__c__unimportant='1', > somerelation__somecriteria='1') > }}} > > it works as expected. > > My testing arena can be found here: > https://gist.github.com/kingbuzzman/9fe5470e31a421aa88b2a64e5447e147 see > the comments, for the way to run it. New description: I ran this on all the "recent" versions of python and i see the issue on all of them. At this point, im not 100% sure if it is a problem or not, i ran across this trying to show some counts in the Admin that had some search_fields that traversed the model backwards and forwards in order to match the thing properly. This "bug" can be seen from 1.11-3.0. Havent checked 3.1 This is my mocked models of the issue: {{{ class ModelA(models.Model): somecriteria = models.CharField(max_length=50) class ModelC(models.Model): unimportant = models.CharField(max_length=50) class ModelB(models.Model): somerelation = models.ForeignKey(ModelA, on_delete=models.CASCADE) m2m = models.ManyToManyField( ModelC, through='ModelBC' ) class ModelBC(models.Model): b = models.ForeignKey(ModelB, on_delete=models.CASCADE) c = models.ForeignKey(ModelC, on_delete=models.CASCADE) }}} The "bug" is shown when i do: {{{ queryset = ModelB.objects.select_related('a').annotate(num_c=Count('m2m__id')).values('num_c') queryset = queryset.filter(Q(modelbc__c__unimportant='1') | Q(somerelation__somecriteria='1')) }}} When i do: {{{ queryset = ModelB.objects.select_related('a').annotate(num_c=Count('m2m__id')).values('num_c') queryset = queryset.filter(modelbc__c__unimportant='1', somerelation__somecriteria='1') }}} it works as expected. My testing arena can be found here: https://gist.github.com/kingbuzzman/9fe5470e31a421aa88b2a64e5447e147 see the comments, for the way to run it. -- -- Ticket URL: <https://code.djangoproject.com/ticket/31581#comment:2> Django <https://code.djangoproject.com/> The Web framework for perfectionists with deadlines. -- You received this message because you are subscribed to the Google Groups "Django updates" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-updates+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-updates/069.8e83b6ffa4b3442da01fd194f616caaf%40djangoproject.com.