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I am building a small Task Manager, all Tasks have Labels. I need to Select all tasks which have a few Labels. At the Moment, I am doing:

    tasks = Task.objects.all().filter(labels__in=label_list).distinct()

which returns all tasks, where at least one label is also in label_list, but I need only the Tasks that have all labels that are in label_list.

More precise example: If I pass by ['1', '2'] as label_list, I don't want all Tasks with either label 1 OR label 2 to be returned (that is what is happening now), but want all Tasks with Label 1 AND Label 2 to be returned.

I want the Tasks which Labels contain label list

The Relation Task-Label is ManyToMany:

class Task(models.Model):
    ....
    labels = models.ManyToManyField(Label, null=True, blank = True)
    ....
kave
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  • Similar question [here](http://stackoverflow.com/questions/13270513/django-manytomany-filter-matching-on-all-items-in-a-list). The selected answer would work for you, and although hackish, it is quite creative. – dgel Oct 08 '14 at 22:57

1 Answers1

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This is reaching the limits of django's ORM, but you could try:

labels = ['1', '2']
qs = Task.objects.all()
for label in labels:
    qs = qs.filter(labels=label).distinct()

Obviously pretty ugly, and it would be a pretty expensive operation for a long list of labels, but it might work to get you by.

Alternatively, you could check out django-taggit which is a mature django tagging application that provides similar 'label' functionality. They handle the 'contains' issue by using raw SQL.

dgel
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