Is it possible to combine annotations with defer/only in django 1.2.1?
I have two simple models: Book, and Author
Each Book has one Author, linked through a foreignkey.
Things work normally until I try to use defer/only on an annotation:
authors=Author.objects.all().annotate(bookcount=Count('books'))
that works. The query looks like:
select table_author.name, table_author.birthday, COUNT(table_book.id) as bookcount
from table_book left outer join table_author on table_author.id=table_book.author_id
group by table_author.id
so very simple - selecting everything from author, and additionally selecting a count of the books.
But when I do the following, everything changes:
simple=authors.defer('birthday')
now, the simple query looks like this:
select COUNT(t开发者_如何转开发able_book.id) as bookcount from table_book left outer join
table_author on table_author.id=table_book.author_id group by table_author.id
and it has completely lost the extra information. What's the deal?
Well, this would seem to be a bug. There's already a ticket, but it hasn't had much attention for a while. Might be worth making a post to the django-developers Google group to chivvy things along.
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