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POHow to model one way one-to-one relationship in Django
 

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  1. POHow to model one way one-to-one relationship in Django
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    <p>I want to model an article with revisions in Django:</p> <p>I have following in my article's models.py:</p> <pre><code>class Article(models.Model): title = models.CharField(blank=False, max_length=80) slug = models.SlugField(max_length=80) def __unicode__(self): return self.title class ArticleRevision(models.Model): article = models.ForeignKey(Article) revision_nr = models.PositiveSmallIntegerField(blank=True, null=True) body = models.TextField(blank=False) </code></pre> <p>On the artlcle model I want to have 2 direct references to a revision - one would point to a published revision and another to a revision that is being actively edited. However from what I understand, OneToOne and ForeignKey references generate a backreference on the other side of the model reference, so my question is, how do i create a one-way one-to-one reference in Django?</p> <p>Is there some special incantation for that or do I have to fake it by including state into revision and custom implementations of the fields that ask for a revision in specific state?</p> <p><strong>Edit:</strong> I guess, I've done somewhat poor job of explaining my intent. Let's try it on a higher abstraction level:</p> <p>My original intent was to implement a sort of revisioned article model, where each article may have multiple revisions, where one of those revisions may be "published" and one actively edited.</p> <p>This means that the article will have one-to-many relationship to revisions (represented by <code>ForeignKey(Article)</code> reference in <em>ArticleRevision</em> class) and two one way references from Article to revision: <em><code>published_revision</code></em> and <em><code>edited_revision</code></em>.</p> <p>My question is mainly, how can I model this with Django's ORM.</p>
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    1. USRoland Tepp
    1. USRoland Tepp
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    1. CONot really an answer, but there are already a couple solutions for versioning Django models, e.g. django-reversion (http://code.google.com/p/django-reversion) or AuditTrail (http://code.djangoproject.com/wiki/AuditTrail). Maybe one of them fits your needs and you don't have to reinvent the wheel :-)
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      1. USBenjamin Wohlwend
    2. COI do not want automatic versioning of my models (that is what these two do). What I am looking for is more of a "manual" revisioning, where an article revision _is_ an article until it gets published. Any edits to a published article will create a new revision. Publishing the new revision will lock this revision and set it up as published revision and next edit on the article will repeat the edit-publish cycle anew (I personally believe that this is much more manageable scheme for regular users than "every edit is a revision" approach).
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      1. USRoland Tepp
 

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