在django模型上强制建立与正式FK不相关的模型的关系

Question

I'm trying to figure out how to get the django admin system to display my models as inlines, when there isn't a direct FK from child to parent model.

I have three models (pseudo code):

class CampaignMain(models.model):
    ...

class CampaignMonitor(models.model): 
    campaign = models.OneToOneField(CampaignMain, pk=True)

class CampaignTransaction(models.model):
    campaign = models.ForeignKey(CampaignMain)

So both CampaignMonitor and CampaignTransaction FK CampaignMain, which is the way I need it to be structured.

Here's the bit I can't fathom: I need an admin page showing CampaignMonitor with CampaignTransaction as inlines. But when I try this, I get "error no fk in CampaignTransaction pointing to CampaignMonitor"

Is there a way to "force" the relationship just for the admin page? Or is there a generic FK option? I saw something in contrib/contenttypes, but it doesn't seem to be what I need. Or am I going to have to build a custom admin section to two models in that way?

As always advice is greatly appreciated.

imanc

Answer 1

Instead of OneToOneField you can use Multi-table inheritance , which implemented using a one-to-one relationshinp:

class CampaignMonitor(CampaignMain): 
    ...

Now modify CampaignMonitor's admin as needed for your needs.