Question

我试图通过三个相关中间模型的字段来命令QuerySet。让我简化我当前的场景，假设我有这些模型。

class User(AbstractUser):
    phone = models.CharField(max_length=20, blank=True, null=True)
    city = models.CharField(max_length=50, blank=True, null=True)
    address = models.CharField(max_length=150, blank=True, null=True)
    about_me = models.CharField(max_length=200, blank=True, null=True)

class School(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    modified = models.DateTimeField(auto_now=True)
    name = models.CharField(max_length=50, verbose_name=_(u'Name'))
    email = models.EmailField(blank=True, verbose_name=_(u'Email'))
    phone = models.CharField(max_length=15, blank=True,
                         verbose_name=_(u'Phone'))

    admins = models.ManyToManyField(User,
                                    verbose_name=_(u'Administrators'),
                                    through='SchoolAdmins',
                                    related_name='school_administered')


    assistants = models.ManyToManyField(User,
                                        verbose_name=_(u'Assistants'),
                                        through='SchoolAssistants',
                                        related_name='school_assisted')


    instructors = models.ManyToManyField(User,
                                         verbose_name=_(u'Instructors'),
                                         through='SchoolInstructors',
                                         related_name='school_instructed')


class SchoolAdmins(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL)
    school = models.ForeignKey(School)
    order = models.PositiveSmallIntegerField(default=0, verbose_name=_(u'Staff ordering number'))



class SchoolAssistants(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL)
    school = models.ForeignKey(School)
    order = models.PositiveSmallIntegerField(default=0, verbose_name=_(u'Staff ordering number'))


class SchoolInstructors(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL)
    school = models.ForeignKey(School)
    order = models.PositiveSmallIntegerField(default=0, verbose_name=_(u'Staff ordering number'))

注意中间模型SchoolAdmins，SchoolInstructors和SchoolAssistants中的订单字段，它用于表示在模板中呈现用户时的视图排序级别，因此，指定的顺序很重要（尽管它可以是None，zero或者甚至重复）

那就是说，我需要返回一个由中间模型的order字段排序的QuerySet。

轻松获取用户：

        qs = User.objects.filter(Q(schoolassistants__school__id=school_id) |
                             Q(schooladmins__school__id=school_id) |
                             Q(schoolinstructors__school__id=school_id))

但我不确定如何根据订单字段订购查询集......这是否可能？如果可能的话，我想避免在Python中这样做......

通过相关的M2M字段Django订购查询集

0 个答案: