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PODjango ORM - How to combine annotate and filter
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copied!<p>I have the following models:</p> <pre><code>class UserProfile(models.Model): user = models.ForeignKey(User, unique=True, related_name='profile') starred_authors = models.ManyToManyField(Author, related_name='users_with_stars') class Author(models.Model): name = models.CharField(max_length=250) slug = models.SlugField(unique=True) </code></pre> <p>And then in the author template, I would like to show whether or not the currently logged in user has starred that author, but I am running into trouble constructing a suitable query to get this data with the ORM.</p> <p>In the view I had thought to annotate an author object with a count that will be 0 if the author has not been starred, or 1 if starred. Something like this:</p> <pre><code>def author_detail(request, slug): user_id = request.user.pk author = Author.objects.filter(slug=slug).filter(users_with_stars__user__pk=user_id).annotate(fav=Count('users_with_stars'))[0] return render_to_response('app/author_detail.html', { 'author': author}, context_instance=RequestContext(request)) </code></pre> <p>But the above is no good because no objects are found if the current user hasn't starred the author. What I would like to do is somehow put the last filter inside the annotate, but I haven't been able to get that working.</p> <p>Ideally in the template I want to do something like:</p> <pre><code>{% if author.fav %} <p>This is one of your favorite authors</p> {% endif %} </code></pre> <p>Any advice is appreciated.</p>

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