TypeError: SET_NULL() missing 4 required positional arguments: 'collector', 'field', 'sub_objs', and 'using'

Question

How do i solve the above error which shows up not during the makemigrations but during migrate in Django.

class Comment(models.Model):
    #comment_id=models.IntegerField(primary_key=True)
    name=models.CharField(max_length=100, default="No Comment Added")
    comment_created=models.DateTimeField(auto_now_add=True)
    task=models.ForeignKey(task_check, on_delete=models.SET_NULL, null=True )
    task_records=models.ForeignKey(task_check_Records, on_delete=models.CASCADE, null=True, default=models.SET_NULL)
    def __str__(self):
        return self.name

Answer 1

you must set models.SET_NULL for on_delete

django documentation

Answer 2

Remove files from app_name/migrations and migrate after makemigrations again.