python - Django deleting querysets with paging, not catching all parts of the set -


i have bit of strange problem i'm not quite able explain.

i have django project old, stale objects lying around. example, lets objects this:

class blog_post(models.model):     user_account = models.foreignkey('accounts.account')     text = models.charfield(max_length=255)     authors = models.manytomanyfield(author)     created =  models.datetimefield(blank=true, null=true)

this not exact copy of model, close enough.

i've created management command build ordered querysets of these objects, , delete with paginator

my command looks this:

all_accounts = account.objects.all() act in all_accounts.iterator():     stale_objects = blog_post.objects.filter(user_account=act,      created=django.utils.timezone.now() - datetime.timedelta(days=7))      paginator = paginator(stale_objects.order_by('id'), 100)     page in range(1, paginator.num_pages + 1):         page_stale_objects = blog_post.objects.filter(id__in=paginator.page(page).object_list.values_list('id'))         page_stale_objects.delete()

the problem i'm having is, after delete these objects command, there still objects fit queryset parameters not deleted. so, have run command 3+ times find , remove objects.

i first figured date range weirdly on edge of datetime not catching objects made shortly after 1 week past command time. not case, i've removed created=... filter queryset, , have same results.

why querysets not catching objects first time command runs? there not excessive objects, @ ~30,000 rows.

paging through queryset translated consecutive limit/offset calls. so, think sequence:

  • get items offset 0 , limit 20
  • delete items
  • get next page, ie 20 items offset 21

but wait! once we've deleted first set, queryset starts @ 0 again. items 0 20 skipped.

the solution is, don't this. pagination displaying objects, not deleting them.


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