On Thu, Jul 21, 2011 at 10:50 PM, nixlists <nixmli...@gmail.com> wrote:
> On Thu, Jul 21, 2011 at 2:17 PM, Jani Tiainen <rede...@gmail.com> wrote: > > Hi, > > So you want to tie Contract with Product(s) with rebate_pct? You then > need > > custom intermediary m2m table say "ContractProduct" > > <see > https://docs.djangoproject.com/en/1.3/topics/db/models/#intermediary-manytomany > > > > for more. So in the end your models would probably look a alike > following: > > class Contract(): > > contract_id = models.lIntegerField(...) > > products = models.ManyToManyField(Product, through='ContractProduct') > > class ContractProduct(): > > contract = models.ForeignKey(Contract) > > product = models.ForeignKey(Product) > > rebate_pct = models.DecimalField(max_digits=4, decimal_places=2) > > So now you can link Contract with multiple Products adding custom > rebate_pct > > value to each link. > > And what comes to rebate value, I think you want to keep value with > product > > linkage for two reasons: > > 1) It's a single scalar value > > 2) It's probably something that should not be changed ever after saving. > > hth, > > Thanks for your response, I think this will work. How would I write a > query to find the rebate_pct per contract per product? > > ContractProduct.objects.all() Following might work also (not sure, but is easy to test in shell for example): for c in Contract.objects.all(): for cp in c.contractproduct_set.all(): print c, cp.product, cp.rebate_pct -- Jani Tiainen -- 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 django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
