在 Django 中查询多对多关系

Question

我正在试验 Django，我正在尝试找出多对多关系。假设我有一个名为“Facility”的模型，类似地我创建了另一个名为“Hotels”的模型，其中包含字段 'facility' 和 'featured_facility' 都与“Facility”处于多对多关系。我只想在 'facility' 字段中可用时添加 featured_facility 我该怎么做？这是我的模型代码。

class Facility(models.Model):
    name = models.CharField(
        max_length=100,
        validators=[validate_facility_name],
        unique=True,
    )
    description = models.CharField(max_length=100, validators=[validate_facility_description])
    can_be_featured = models.BooleanField(default=False)

同样酒店型号是

class Hotels(models.Model):
    hotel_name = models.CharField(
        max_length=20,
        unique=True,
        validators=[validate_hotel_name]
    
    facility = models.ManyToManyField(
        Facility,
        related_name='hotel_facility',
        blank=True,
    )
    featured_facility = models.ManyToManyField(
        Facility,
        related_name='featured_hotel_facility',
        blank=True,
    )

    class Meta:
        default_permissions = ()
        verbose_name = 'Hotel'
        verbose_name_plural = 'Hotels'

    def __str__(self):
        return self.hotel_name

现在我想添加 'featured_facility' 仅当它在 'facility' 中可用时不能在 'featured_facility' 中添加来自 Facility 的新特色设施我一直在查询多对多关系部分？

Answer 1

测试这个

f = Facility(name='hello', can_be_featured=True, ...)
f1 = Facility(name='hello2', can_be_featured=True, ...)

hotel = Hotels.objects.first()
hotel.facility.add(f)

if f1 in hotel.facility.all():
   hotel.featured_facility.add(f1)

Answer 2

我这样试过

def _factory(self):
    featured_facility = Facility.objects.filter(can_be_featured=True)
    # print(featured_facility, '-------', self._data.get('facility'))
    if set(self._data.get('facility')).issubset(set(featured_facility)):
        self._bus.featured_facility.add(*self._data.get('facility'))
    else:
        raise ValidationError({'error': _('This facility is not featured at the moment.')})

在 Django 中查询多对多关系

Querying Many To Many relationship in Django

python

django

django-models

django-orm

django-rest-framework