Re: outer join in orm

On Jun 21, 12:51 pm, JeffH <holtzma...@gmail.com> wrote:
> I have some models that (simplified) look like the following.
>
> class Answer(models.Model):
>     id = models.CharField(max_length=32, primary_key=True)
>     text = models.TextField(blank=False)
>     question = models.ForeignKey(Question)
>     candidate = models.ForeignKey(Candidate)
>
> class Question(models.Model):
>     id = models.CharField(max_length=32, primary_key=True)
>     text = models.TextField(blank=False)
>
> class Candidate(models.Model):
>     id = models.CharField(max_length=32, primary_key=True)
>     name = models.CharField(max_length=32, blank=False)
>
> class Race(models.Model):
>     id = models.CharField(max_length=32, primary_key=True)
>     name = models.CharField(max_length=128, blank=False)
>     questions = models.ManyToManyField(Question)
>     candidates = models.ManyToManyField(Candidate)
>
> So, a Race has Candidates and Questions, and a Candidate has Answers.
> Each answer is associated with a Question and a Candidate. Displaying
> the question associated with an answer is easy:
>
> # context variable in view
>     answers = Answer.objects.filter(candidate=candidate)
>
> # template code
>     <table>
>     {% for answer in answers %}
>     <tr>
>         <td>{{answer.question.text}}</td>
>         <td>{{answer.text}}</td>
>     </tr>
>     {% endfor %}
>     </table>
>
> From the point of view of the Candidate, I need to display all the
> questions, including the ones without Answers. I know how to to do
> this using raw sql and an outer join. How to do it in the orm?
>
> Thanks in advance for any ideas.
>
> --Jeff

Not quite enough information here to answer. What are you wanting to
join? If you just want to display all the questions, why do you need a
join at all?
--
DR.

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