Remove rows with same ID from two lists in Django

Question

I have a list of objects called checkins that lists all the times a user has checked into something and another set of objects called flagged_checkins that is certain checkins that the user has flagged. They both reference a 3rd table called with a location_id

I'd like to take the two lists of objects, and remove any of the checkins which have a location_id in flagged_checkins

How do I compare these sets and remove the rows from 'checkins'

Two questions: 1. Are both belonging to the same model? 2. Is flagged_checkins definitely a subset of checkins? — Sandip Agarwal, Dec 22 '11 at 05:32

score 0 · Accepted Answer · edited May 23 '17 at 10:08

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As per this SO question,

checkins.objects.filter( location_id__in = list(flagged_checkins.objects.values_list('location_id', flat=True)) ).delete()

edited May 23 '17 at 10:08

Community

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answered Dec 22 '11 at 05:31

thatwasbrilliant

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But this would remove the objects at the database level as well. – Sandip Agarwal Dec 22 '11 at 05:42
Well, I'll remove the .delete() and try it – Brenden Dec 22 '11 at 21:21

score 0 · Answer 2 · answered Dec 22 '11 at 05:44

If you are talking about a queryset then, you can definitely try:

checkins.objects.exclude( location_id__in = list(flagged_checkins.objects.values_list('location_id', flat=True)) )

This would remove the objects based on your criteria. But not from the db level.

Remove rows with same ID from two lists in Django

2 Answers2