Django QuerySet access foreign key field directly, without forcing a join -

suppose have model entry, field "author" pointing model author. suppose field can null.

if run following queryset:

entry.objects.filter(author=x)

where x value. suppose in mysql have setup compound index on entry other column , author_id, ideally i'd sql use "author_id" on entry model, can use compound index.

it turns out entry.objects.filter(author=5) work, no join done. but, if author=none, django join author, add clause author.id null. in case, can't use compound index.

is there way tell django check pk, , not follow link?

the way know add additional .extra(where=['author_id null']) queryset, hoping magic in .filter() work.

thanks.

(sorry not clearer earlier this, , answers lazerscience , josh).

does not work expected?

entry.objects.filter(author=x.id) 

you can either use model or model id in foreign key filter. can't check right yet if executes separate query, though i'd hope wouldn't.