psycopg2.IntegrityError: duplicate key value violates unique constraint DETAIL: Key (id)=(19) already exists

I am not setting the primary key manually. How could this be happening?

class Image(models.Model):
    title = models.CharField(max_length=255)
    image = models.ImageField(upload_to='attack_images', blank=True, null=True)
    source_url = models.URLField(blank=True,null=True)
    domain = models.ForeignKey(Domain, on_delete=models.CASCADE, blank=True, null=True)
    creator = models.ForeignKey(User, on_delete=models.CASCADE, blank=True,null=True)
    slug = models.SlugField(blank=True,null=True)

In my 5 years of programming in Django I’ve never gotten this error. I can’t tell what is going wrong by just looking at my code and the traceback. What could be wrong? Let me know if I need to post more code. Thanks in advance. Any help is appreciated.

Answer

You are trying to save your submodel in your save method.

self.image.save(
                os.path.basename(self.source_url),
                File(open(result[0], 'rb'))
                )

Therefore you are saving your model before calling super’s save method. You should set your image but not save it before calling super’s save method.

self.image = os.path.basename(self.source_url),File(open(result[0], 'rb'))