Re: (Noob) - filtering spanning relationship not working

Calling count() on a queryset will always aggregate the count of all rows. Please have a look at the annotate function in the documentation https://docs.djangoproject.com/en/dev/topics/db/aggregation/ Annotate will group your results and sum up the results. 

I think what you'll have to do is:

assignment.finished_articles = Article.objects.filter(cowcode=country, pubdate__range(start_date, end_date), articlehistory__coder=request.user.id).annotate(number_of_articlehistory_entries=Count(articlehistory__id))

This should give you a list of Articles with an extra column 'number_of_articlehistory_entries' with the count of articlehistory entries per article. I'm pretty sure, that in this list all articles are shown, even those with 0 articlehistory entries.

If you only want those with more than 1 articlehistory entries, you should start the query from the articlehistory class.

assignment.finished_articles = ArticleHistory.objects.filter(article__cowcode=country, article__pubdate__range(start_date, end_date), coder=request.user.id).annotate(number_of_articlehistory_entries=Count(id))

A count on assignment.finished_articles should return the number of articles that have at least 1 connected articlehistory entry.

Hope this helps

Am Montag, 22. Juli 2013 09:51:14 UTC+2 schrieb Lukas Kawerau:

I want to find the number of articles for which a specific user has created articlehistoryrecords.
The models for that look like this:

class Article(models.Model):      """The basic entity of this app.)"""      documentID = models.CharField(blank=True, max_length=1000)      cowcode = models.IntegerField(blank=True, null=True)      pubdate = models.DateField(default=datetime.datetime.today)      headline = models.CharField(blank=True, max_length=1500)      source = models.CharField(blank=True, max_length=5000)      text = models.TextField(blank=True, max_length=1000000)      assignments = models.ManyToManyField(Assignment)        class Meta:          ordering = ['pubdate']        def __unicode__(self):              return self.headline    class ArticleHistory(models.Model):      """(Modelname description)"""      article = models.ForeignKey(Article, related_name='Article History')      coder = models.ForeignKey(User, related_name='Article History')      last_updated = models.DateTimeField(default=datetime.datetime.now)        def __unicode__(self):          return self.last_updated

The way I'm trying to do this at the moment is like this:

assignment.finished_articles = Article.objects.filter(cowcode=country).filter(pubdate__range=(start_date,end_date), articlehistory__coder=request.user.id).count()

This doesn't work, however and exhibits another weird behaviour:
I try to do this:

for assignment in assignments:              country = assignment.country.cowcode              start_date = assignment.start_date              end_date = assignment.end_date              articles = Article.objects.filter(cowcode=country).filter(pubdate__range=(start_date,end_date)).select_related()              assignment.article_num = articles.count()              #assignment.finished_articles = Article.objects.filter(cowcode=country).filter(pubdate__range=(start_date,end_date), articlehistory__coder=request.user.id).count()

This works fine, unless I try to include finished_articles, then article_num gets shortened to one result.

It would be really great if anyone has a pointer to who to solve this.

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