Re: Recursive(?) ManyToMany model
On Mon, Mar 27, 2006 at 12:37:54PM -0800, wam wrote: > Well, it was my understanding that since I have the potential of having > many 'inspired by' documents linked to a particular document, and that > any particular document could have inspired many other other documents, > then that means I'm looking at a many to many relationship. Earlier you wrote: class Doc(meta.Model): ... inspired_by = meta.ManyToManyField(Doc) Based on your comments above, I think you mean: This one Doc can have many other Docs which inspired it. That's a OneToMany relationship. This Doc, and many others, can inspire other Docs -- that's not part of either relationship above. -- Glenn --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---
Re: Recursive(?) ManyToMany model
Malcolm Tredinnick wrote: > Hi William, > I may be missing something, but it sounds like you want a one-to-many > (a.k.a. ForeignKey) relationship here. The 'one' side is the "self" > document in each case with links to 'many' other documents. I don't > believe a ManyToMany relationship is necessary here. > Well, it was my understanding that since I have the potential of having many 'inspired by' documents linked to a particular document, and that any particular document could have inspired many other other documents, then that means I'm looking at a many to many relationship. This seems to compare well to the example Many-to-Many relationship example given at http://www.djangoproject.com/documentation/model_api/ Many toMany Pizzas can have multiple topppings, and any particular topping can be on multiple pizzas. Documents can have multiple inspirations, and any particular document can have inspired many other subsequent documents. Since posting my request, I also ran across the technique described at: http://www.djangoproject.com/documentation/models/m2m_intermediary/ which seems to be applicable to my needs. I'll let you know how it works out... -- William --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---
Re: Recursive(?) ManyToMany model
On 3/27/06, wam <[EMAIL PROTECTED]> wrote: class Doc(meta.Model): title = meta.CharField(maxlength=50) contents = meta.TextField() inspired_by = meta.ManyToManyField(Doc) supercedes = meta.ManyToManyField(Doc)I've obviously been having problem with the recursive nature of the definitions. I saw mention of using 'self' as a special arg forrecursive references in the initializer of a ForeignKey(), butManyToMany() doesn't seem to have this capability. Any suggestions? As of the 0.91 release, you are correct - 'self' referencing doesn't exist for ManyToMany. This is one (of many) areas that is fixed in the magic-removal development stream. For future reference, when referring to another model, you can use either the model name as a python symbol, the model name as a string (useful for forward references), or the string 'self'. In your case, either 'Doc' or 'self' would work. Magic-removal also has improved model validation code, which will pick up the other problem in your model - multiple references on the same table. You are currently describing two relations on the same table, but not providing a 'related_name' to differentiate between the two. Yours,Russ Magee --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---
Re: Recursive(?) ManyToMany model
Hi William, On Sun, 2006-03-26 at 20:16 -0800, wam wrote: > I have a model where I will have a pool of documents that will have > several references to various other documents within the pool. For > example, I'm trying to do something similar to the following: > > class Doc(meta.Model): > title = meta.CharField(maxlength=50) > contents = meta.TextField() > inspired_by = meta.ManyToManyField(Doc) > supercedes = meta.ManyToManyField(Doc) > > I've obviously been having problem with the recursive nature of the > definitions. I saw mention of using 'self' as a special arg for > recursive references in the initializer of a ForeignKey(), but > ManyToMany() doesn't seem to have this capability. Any suggestions? I may be missing something, but it sounds like you want a one-to-many (a.k.a. ForeignKey) relationship here. The 'one' side is the "self" document in each case with links to 'many' other documents. I don't believe a ManyToMany relationship is necessary here. Malcolm --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---
Recursive(?) ManyToMany model
I have a model where I will have a pool of documents that will have several references to various other documents within the pool. For example, I'm trying to do something similar to the following: class Doc(meta.Model): title = meta.CharField(maxlength=50) contents = meta.TextField() inspired_by = meta.ManyToManyField(Doc) supercedes = meta.ManyToManyField(Doc) I've obviously been having problem with the recursive nature of the definitions. I saw mention of using 'self' as a special arg for recursive references in the initializer of a ForeignKey(), but ManyToMany() doesn't seem to have this capability. Any suggestions? -- William P.S. This is my first 'real' Django app I've worked on outside of the tutorial, so don't be surprised if you hear from me again. :-) --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---
