On Mar 18, 2011, at 6:38 AM, Ricardo F. Teixeira wrote:
> Hi everyone!
>
> Without using raw SQL queries how can I make multiple joins using this
> model?
>
Do a search for "django select_related reverse one to many" for some
alternatives
> I'm trying to get something like this:
>
> SELECT Package.package, Release.release, Release.version,
> ContribComment.*
> FROM ContribComment
> INNER JOIN Contrib
> ON Contrib.id = ContribComment.fk_contrib_id
> INNER JOIN ContribRelease
> ON ContribRelease.fk_contrib = Contrib.id
> INNER JOIN Release
> ON Release.id = ContribRelease.id
> INNER JOIN Package
> ON Package.id = Release.fk_package
>
> Is that possible to anchive something like this without using raw SQL
> queries?
> I'm asking that because I can't find any example with multiple inner
> joins that is similar to my model.
>
What you want work is:
Package.objects.select_related()
But since the ORM will only follow 'forward' ForeignKey references,
the result will be the same as:
Package.objects.all()
You can get close with
ContribRelease.objects.select_related()
which will inner join everything except ContribComment since there is no
"forward" ForeignKey reference
see http://docs.djangoproject.com/en/dev/ref/models/querysets/#select-related
> class ContribComment(models.Model):
> fk_contrib_id = models.ForeignKey(Contrib)
> subject = models.TextField()
> text = models.TextField()
> ratings = models.IntegerField()
>
> class Contrib(models.Model):
> username = models.TextField()
> city = models.TextField()
>
> class ContribRelease(models.Model):
> fk_contrib = models.ForeignKey(Contrib)
> fk_release = models.ForeignKey(Release)
>
> class Release(models.Model):
> fk_package = models.ForeignKey(Package)
> release = models.TextField()
> version = models.TextField()
> distribution = models.TextField()
> arch = models.TextField()
> summary = models.TextField()
> description = models.TextField()
>
> class Package(models.Model):
> name = models.TextField(unique=True)
> homepage = models.TextField()
> snapshot = models.TextField()
>
> Thanks,
>
> Ricardo F. Teixeira
>
Jason
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