I made standard class of django.model
    class Standard(models.Model):
    name = models.CharField(max_length=300, default='default name')
    description = models.TextField()
    link = models.TextField()
    createat = models.DateTimeField(auto_now_add=True)
    random = models.TextField(max_length=300, default="random")
    category = models.ForeignKey(StandardCategory, on_delete=models.CASCADE)
    requirement = models.ForeignKey(StandardRequirement, on_delete=models.CASCADE)
    def __str__(self):
        return self.name
but have the problem when I compile it
web_1    | django.db.utils.OperationalError: no such column: app_standardrequirement.createat
How to resolve this error?