Relationships in Django does not allow CASCADE delete
|Reported by:||Owned by:||nobody|
|Component:||Database layer (models, ORM)||Version:||1.3|
|Has patch:||no||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
Description (last modified by )
I've been through this ticket alert that Django relationships are wrong.
A simple example:
An owner has an address.
A house has an address.
The classes would be:
class Owner(models.Model): address = models.ForeignKey(Address) #or better # address = models.OneToOneField(Address) class House(models.Model): address = models.ForeignKey(Address) #or better # address = models.OneToOneField(Address) class Address(models.Model): street = models.CharField(max_length=100) number = models.IntegerField(default=0)
This is the correct mapping following the logic of object-orientation, but this mapping does not allow remove related objects by CASCADE.
According to the Django doc, the mapping is inverse:
class Owner(models.Model): #other fields class House(models.Model): #other fields class Adress(models.Model): street = models.CharField(max_length=100) number = models.IntegerField(default=0) owner = models.ForeignKey(Owner) house = models.ForeignKey(House)
The big problem is that this mapping in the form of owner the address form is shown with a select of houses, and in the form of owner is shown a form address with a select of owners.
Look, I want to register an owner and his address, this is end of the registration.
After i want register a house, register your address and there can select the owner to associate home with owner.
I urge to carefully read the Hibernate reference manual to understand how relationships should be made in Django:
I would like to examine this problem because i can not remove an owner and remove the house and address by CASCADE, and remove a house and its address by CASCADE using my firts example for mapping class.