UNIQUE constraint failed: new__main_post.author_id in django

Question

i added a new field to my models.py but when i try to migrate i get this error my models.py:

from django.db import models
from django.utils import timezone
from django.contrib.auth.models import User
from django.urls import reverse
class Post(models.Model):
    title = models.CharField(max_length=100)
    content = models.TextField()
    date_posted = models.DateTimeField(default=timezone.now)
    author = models.OneToOneField(User, on_delete=models.CASCADE)
    likes = models.ManyToManyField(User, related_name='blog_posts')
    
    
    def get_absolute_url(self):
        
        return reverse('post-detail', kwargs={'pk': self.pk})
    
        



    

Answer 1

Use a one to many relationship with models.ForeignKey

https://docs.djangoproject.com/en/3.0/topics/db/examples/many_to_one/

class Post(models.Model):
    title = models.CharField(max_length=100)
    content = models.TextField()
    date_posted = models.DateTimeField(default=timezone.now)
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    likes = models.ManyToManyField(User, related_name='blog_posts')
    
    
    def get_absolute_url(self):
        
        return reverse('post-detail', kwargs={'pk': self.pk})