Django - Get Foreign key objects in single query?

Question

I'm finding django foreign keys a bit confusing, is there any way to do the view below, using a single query?

# Model class Programme(models.Model):     name = models.CharField(max_length = 64)  class Actor(models.Model):     programme = models.ForeignKey(Programme)     name = models.CharField(max_length = 64)   # View def list_actors( request, programme_id):     programme = Programme.objects.filter(id = programme_id)[0]     actors = Actor.objects.filter(programme = programme_id)     json = simplejson.dumps( [{         'name': str(actor.name),         'rating': str(actor.rating),} for actor in actors] )     return HttpResponse(json, mimetype='application/javascript') 

Answer 1

I think you are looking for select_related().

This line:

actors = Actor.objects.filter(programme = programme_id) 

should look like this:

actors = Actor.objects.select_related().filter(programme = programme_id) 

Unfortunately as emphasized here: Get foreign key objects in a single query you will only be able to retrieve actors that way as select_related only works on objects having ForeignKeys and not vice versa.

Answer 2

You query Programme and assign to programme, but you never use the result anywhere. Just remove that line.