CODEWITHSUNDEEP
pythondjangodjango-database
arjun
arjun

Reputation: 2431

django database delete specific number of entries

How to delete specific number of entries from the database? I did something like this

EntriesToDelete=Statusmessages.objects.filter(time__lt=date)[:30000]
EntriesToDelete.delete()

But I get an error which says: AssertionError. Cannot use 'limit' or 'offset' with delete.

How can I specify the number of entries to be deleted.

Upvotes: 21

Views: 12490

Answers (3)

jpic
jpic

Reputation: 33420

You could do it like this:

pks = (Statusmessages.objects
       .filter(time__lt=date)
       .values_list('pk')[:30000])
Statusmessages.objects.filter(pk__in=pks).delete()

Upvotes: 49

Solomon Botchway
Solomon Botchway

Reputation: 789

If you get the following error:

django.db.utils.NotSupportedError: (1235, "This version of MariaDB doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'")

Force evaluate the list of ids with list(). Here's an example:

sessions_to_delete = LoginSession.objects.filter(user=self.userProfile)[3:]
pks_of_sessions_to_delete = list(sessions_to_delete.values_list("pk", flat=True))
LoginSession.objects.filter(pk__in=pks_of_sessions_to_delete).delete()

Upvotes: 1

ChenDehua
ChenDehua

Reputation: 107

use this:

Statusmessages.objects.filter(pk__in=Statusmessages.objects.filter(time__lt=date).values_list('pk', flat=True)[:30000]).delete()

use flat=True, if not then is a tuple and raise exception:

{NotSupportedError}(1235, "This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'")

Upvotes: 1

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