Django 我是新手。我将如何在管理页面中验证注册的主题不会在条目中重复？

这是我的模特

class SubjectsEnrolled(models.Model):
student =  models.ForeignKey(Student)
STATUS = (
    ('1', 'Passed'),
    ('2', 'Failed'),
    ('3', 'No Grade'),
    ('4', 'Incomplete'),
)
subject = models.ForeignKey(Subject)
grade = models.CharField(max_length=100, blank=True, null=True)
status = models.CharField(max_length=2, choices=STATUS, blank=True, null=True)
schoolterm = models.ForeignKey(SchoolTerm)

class Meta: 
    verbose_name = _('Subjects Enrolled') 
    verbose_name_plural = _('Subjects Enrolled')

这是我的管理员

class SubjectsEnrolled(models.Model):
student =  models.ForeignKey(Student)
STATUS = (
    ('1', 'Passed'),
    ('2', 'Failed'),
    ('3', 'No Grade'),
    ('4', 'Incomplete'),
)
subject = models.ForeignKey(Subject)
grade = models.CharField(max_length=100, blank=True, null=True)
status = models.CharField(max_length=2, choices=STATUS, blank=True, null=True)
schoolterm = models.ForeignKey(SchoolTerm)

class Meta: 
    verbose_name = _('Subjects Enrolled') 
    verbose_name_plural = _('Subjects Enrolled')

学生应该在学期中有一个主题，并且该主题不应该在学期中重复。

使用元选项

class Meta:
    unique_together = ('subject', 'schoolterm')

---

之后，验证将在任何地方执行，而不仅仅是在管理员中。

这两个代码块是相同的。你能发布管理员代码吗？