python - 在 django 模型中将字段设置为主键

Question

我在 ubuntu 18.04 上使用 django 2.2 和 python 3.6.8。我创建了一个如下模型：

@reversion.register()
class Courses(BaseModel):
    coursecode = models.AutoField(primary_key=True, verbose_name=_("Kurs Kodu"))
    coursename = models.ForeignKey(CourseNames, on_delete=models.PROTECT, verbose_name=_("Kurs"))
    teacher = models.ManyToManyField(Staff, blank=True,  related_name='teacher', verbose_name=_("Öğretmenler"))
    courseroom = models.ForeignKey(CourseRoom, on_delete=models.PROTECT, verbose_name=_("Kurs Yeri"))
    credit = models.DecimalField(verbose_name=_("Kredi"), default=0.0, max_digits=3, decimal_places=1)
    student = models.ManyToManyField(Student, blank=True, verbose_name=_("Öğrenci"))
    createdon = models.DateField(verbose_name=_("Oluşturulma Tarihi"))
    createdby = models.ForeignKey(Staff, on_delete=models.PROTECT,  related_name='creatorstaff', verbose_name=_("Kaydeden Personel"))
    coursenotes = models.TextField(null=True, blank=True, verbose_name=_("Kurs Notları"))

    class Meta:
        permissions = (
            ("list_course", _("List Courses")),
        )
        ordering = ['coursename']
    def __str__(self):
        return "%s - %s" % (self.coursename, self.courseroom, self.teacher)

当我尝试进行迁移时，出现以下错误：

project1app.Courses: (models.E026) 模型不能有多个“primary_key=True”字段。

当我设置一个主键字段时，django 不应该设置自动主键并使用我的。主键只有一个字段。但给出以下错误。