투표(Votes) 기능 구현하기 1 - Models polls/models.py from django.contrib.auth.models import User class Vote(models.Model): question = models.ForeignKey(Question, on_delete=models.CASCADE) choice = models.ForeignKey(Choice, on_delete=models.CASCADE) voter = models.ForeignKey(User, on_delete=models.CASCADE) class Meta: constraints = [ models.UniqueConstraint(fields=['question', 'voter'], name='unique_vote..