[Answer]-Django, table inheritance: insert data

When creating an id manually you should use AutoField instead of IntegerField

id_dato = models.AutoField(primary_key=True)

https://docs.djangoproject.com/en/1.6/ref/models/fields/#autofield

What is happening is that since you are not explicitly defining the ‘datos’ object’s id it doesnt have one, and then producto complains because the key can’t have an empty value.

AutoField should fix this

I am surprised it doesn’t fail at the earlier line: datos.save() because you have not supplied a value for the primary key datos.id_dato

Normally in Django you would need to use an AutoField to get an auto-incrementing primary key.

Also you should not be specifying primary_key=True on the OpeProductos.iddato field, you can only have one primary key per model.

Then the error you are seeing is due to the fact that datos.id_dato is None since you did not provide any value for it before saving the datos instance.