I have a question regarding objects modelling. Let's say we have a one to many relationship where an object A instance could have 0 to many linked objects B whereas object B could be linked to one and only one object A (note here object B cannot be created without being linked to an object B). So far I have added a foreign key to object B model, when adding that object I should select an Object A , so far so good. My question now is do I have to also add the object B to object A model on database level? Or should I just do it on API level by creating nested APIs? So that getting object B would be this way :
get : http://localhost/api/objectA/objectB
I hope I was clear explaining my question but to summarize I am not sure if adding a foreign key to represent a : 0.n---->1.1 is enough.
It has been a long time for me that I did not design a database am I using a very old methodology?
Thanks
Santiago Trujillo
My question now is do I have to also add the object B to object A model on database level?
No. If you constructed a relation like a ForeignKey, you can let Django query in reverse. So if you have two models:
class A(models.Model):
pass
class B(models.Model):
a = models.ForeignKey(A, on_delete=models.CASCADE)Then you can obtain all B objects that belong to some A object somea with:
somea.b_set.all()You can rename the relation in reverse by setting the related_name=… parameter [Django-doc]. So you can specify the relation as:
class A(models.Model):
pass
class B(models.Model):
a = models.ForeignKey(
A,
related_name='bs',
on_delete=models.CASCADE
)and then query with:
somea.bs.all()