Question

I have two models:

A(models.Model):
    field = models.IntegerField()

B(models.Model):
    f = models.ForeignKey(A)

And in admin panel I have custom action, which clears(resets) some info in Model A:

def clear_something(modeladmin, request, queryset):
     queryset.update(field=0)

How could I make custom action clear_something delete all related Model B entries?

Answer 1

Assuming queryset is a set of A’s, you should be able to loop over them and delete the ‘b_set’ (reverse FK lookup) of each, like so:

def clear_something(modeladmin, request, queryset):
    queryset.update(field=0)
    for a in queryset:
        a.b_set.all().delete()

Alternatively, use B’s model manager:

def clear_something(modeladmin, request, queryset):
    queryset.update(field=0)
    for a in queryset:
        B.objects.filter(f=a).delete()