多对多字段引用自己 [英] ManyToMany Field Refere to Itself

问题描述

如何制作我的模型以便其ManyToMany引用用户

How can make my model so that its ManyToMany Refer to User

class User(AbstractUser):
    teacher_or_student = models.CharField(max_length=100)
    mobile_number = models.CharField(max_length=100)
    grade = models.CharField(max_length=100)
    laptop_yes_or = models.CharField(max_length=100)
    students = models.ManyToManyField(User)

推荐答案

为此传递'self'字符串。默认情况下，一个指向自身的 ManyToManyField 是对称的 ，所以您可能想将其关闭，因为如果 a 是 b 的学生，那么 b 本身不是 a 的学生。您可以通过指定 symmetrical = False [Django-doc] ：

You can pass the 'self' string for this. By default a ManyToManyField that refers to itself, is als symmetrical, so you probably want to turn that off, since if a is a student of b, then b is not per se a student of a. You can do that by specifying symmetrical=False [Django-doc]:

class User(AbstractUser):
    teacher_or_student = models.CharField(max_length=100)
    mobile_number = models.CharField(max_length=100)
    grade = models.CharField(max_length=100)
    laptop_yes_or = models.CharField(max_length=100)
    students = models.ManyToManyField(
        'self',
        symmetrical=False,
        related_name='teachers'
    )

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