django update_or_create gets “duplicate key value violates unique constraint ”

Question

Maybe I misunderstand the purpose of Django\'s update_or_create Model method.

Here is my Model:

from django.db import models
import datetime
from vc.mode         


        

Answer 1

You should separete your field:

1. Fields that should be searching for
2. Fields that should be updated

for example: If I have the model:

class User(models.Model):
    username = models.CharField(max_lenght=200)
    nickname = models.CharField(max_lenght=200)

And I want to search for username = 'Nikolas' and update this instance nickname to 'Nik'(if no User with username 'Nikolas' I need to create it) I should write this code:

User.objects.update_or_create(
    username='Nik', 
    defaults={'nickname': 'Nikolas'},
)

see in https://docs.djangoproject.com/en/2.0/ref/models/querysets/