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POHow to save a django model with a manyToMany Through relationship, AND regular manyToMany relationships
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copied!<p>I've read everything I can find on ManyToMany relationships in Django, but so far I'm not seeing anything that solves my specific problem of having a ManyToMany-Through relationship alongside a simple ManyToMany that Django handles so effortlessly on its own.</p> <p>Consider these models:</p> <pre><code>class Treatment(models.Model): ... book = models.ManyToManyField(Book, through='TreatmentLocation') category = models.ManyToManyField(Category) class Book(models.Model): name = models.CharField(...) class TreatmentLocation(models.Model): treatment = models.ForeignKey(Treatment) book = models.ForeignKey(Book) page = models.CharField(...) class Category(models.Model): name = models.CharField(...) </code></pre> <p>I've got the data coming in on the POST array nicely, but finagling the View is proving tricky.</p> <pre><code>def save_treatment(request): form = TreatmentForm(request.POST) if form.is_valid(): treatment = form.save() pages = request.POST.getlist('page') books = request.POST.getlist('book') counter = 0 for page in pages: book_id = books.__getitem__(counter) TreatmentLocation.objects.create(treatment_id=treatment.id, book_id=book_id, page=page) counter = counter + 1 form.save_m2m() else: ... </code></pre> <p>The Treatment saves successfully, as do the TreatmentLocations, but once I try to call save_m2m() to store the Treatment-Category xrefs, I get the <code>Cannot set values on a ManyToManyField which specifies an intermediary model. Use TreatmentLocation Manager</code> error.</p> <p>Does anyone know how to save both of these things? I'd like to avoid resorting to raw SQL.</p>

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