Clone an inherited django model instance

Question

When I clone a django model instance I used to clean the \'pk\' field. This seems not to work with an inherited model :

Take this :

class ModelA(models.M         


        

Answer 1

c=ModelC(info1="aaa",info2="bbb",info3="ccc")
# creates an instance

c.save()
# writes instance to db

c.pk=None
# I doubt u can nullify the auto-generated pk of an existing object, because a pk is not nullable
c.save()
# if I'm right nothing will happen here.

So c will always be the same object. If you want to clone it you need to generate a new object. Either with a constructor within ModelC:

def __init__(another_modelC_obj=null, self):
   if another_modelC_obj:
      # for every field in another_modelC_obj: do self.field = another_modelC_obj.field
   super().__init__()

so you can go

c2=ModelC(c)

Or call it directly with:

c2=ModelC(c.info1, c.info2, c.info3)

Then c2 and c will be identical despite of their pk