Django：过滤外键

Question

I have the following code:

        query = Entry.objects.all()
        print 'authors ' + repr([x.id for x in authors])
        print 'query ' + repr(query)
        print 'query ids ' + repr([x.author.id for x in query])
        query.filter(author__in=authors)
        print 'filtered ids ' + repr([x.author.id for x in query])

Which outputs this:

        authors [2]
        query [<Entry: test>, <Entry: test>]
        query ids [2, 3]
        filtered ids [2, 3]

Obviously, 3 is not in [2]. So, why filtered ids are [2, 3] and not just [2]?

Regards

Answer 1

When you call query.filter(author__in=authors) , it returns a new queryset. It does not modify the existing queryset.

If you assign the new queryset to query, then you will get the result you were expecting.

query = query.filter(author__in=authors)
print 'filtered ids ' + repr([x.author.id for x in query])

Answer 2

试试这个代替您当前的过滤器：

query = query.filter(author__in=authors)