[Answered ]-Make field of submodel unique in django

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0👍

✅

Maybe its your solution

class Animal(models.Model):
    TYPE = (
        (1, 'Tyger'),
        (2, 'Panter')
    )

    name = models.CharField(max_length=64)
    type_of_animal = models.IntegerField(choices=TYPE)

    class Meta:
        unique_together = [['name','type_of_animal']]

In this case you can create JackyThePanther for ‘Tyger’ and ‘Panter’. You can expand logic, for example add ‘Elephant’ JackyThePanther

>>> animals = Animal.objects.all()
>>> animals = Animal.objects.filter(name='JackyThePanther')
>>> animals
<QuerySet [<Animal: Animal object (1)>, <Animal: Animal object (2)>]>
👤koko

1👍

Model inheritance in Django is rarely the best solution, and I don’t think I’d turn to it in your case. You’re already seeing the pitfalls it can come with in situations that aren’t perfectly suited to it.

Meta.unique_together is a model option that enables what you seem to be looking for, though you’ll have to change the approach you’re using:

class Species(models.Model):
   name = models.CharField(...)

class Animal(models.Model):
   name = models.CharField(...)
   species = models.ForeignKey(Species, on_delete=models.CASCADE)
   
   class Meta:
      unique_together = [['name', 'species']]

In this case, you’d likely maintain a data migration or fixture for species, as your current architecture has them predefined in code.

Note that this uses unique_together, which is currently valid, but the linked documentation mentions that UniqueConstrant is likely more future-proof. I’m sticking with the former as a demonstration here since it’s the one I’ve used.

👤kungphu

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