django - 如何在 Django rest API 检索 View 中获取相关对象？

Question

这里我有两个模型并且有Many-to-one 关系。在 ListPackageGallery 类中，我想列出所有上传到某个包的图像。

如何在这里查询某个特定包的图像？

我是 django rest 的新手。那么在这种情况下使用 generics API view 是否正确？

class Package(models.Model):
    name = models.CharField(max_length=255,unique=True)
    slug = AutoSlugField(populate_from='name')
    package_desc = models.TextField()

class PackageGallery(models.Model):
    package = models.ForeignKey(Package, on_delete=models.CASCADE,related_name='gallery')
    image = models.ImageField(upload_to='package_gallery')

序列化器.py

class PackageGallerySerializer(serializers.ModelSerializer):
    class Meta:
        model = PackageGallery
        fields = '__all__'


 class PackageGalleryDetailSerializer(serializers.ModelSerializer):
    class Meta:
        model = Package
        fields = '__all__'

View .py

class CreatePackageGallery(generics.CreateAPIView):
    serializer_class = PackageGallerySerializer
    queryset = PackageGallery.objects.all()


class ListAllGallery(generics.ListAPIView):
    serializer_class = PackageGallerySerializer
    queryset = PackageGallery.objects.all()


class ListPackageGallery(generics.RetrieveAPIView):
    serializer_class = PackageGalleryDetailSerializer
    lookup_field = 'slug'

    def get_queryset(self):
        return self.gallery.all() #i got stuck here 

网址.py

path('create/gallery/',CreatePackageGallery.as_view(),name='create_package_gallery'),
path('list/all/gallery/',ListAllGallery.as_view(),name='list_all_gallery'),
path('list/<slug>/gallery/',ListPackageGallery.as_view(),name='list_package_gallery'),

Django Version: 2.2.7 Exception Type: AttributeError Exception Value: 'ListPackageGallery' object has no attribute 'gallery'

Answer 1

您可以使用 SerializerMethodField 返回关联图像的列表:

class PackageGalleryDetailSerializer(serializers.ModelSerializer):
    images = serializers.SerializerMethodField()    

    class Meta:
        model = Package
        fields = '__all__'

    def get_images(self, package):
        return [
            # Change this to meet your need e.g. `gallery.image.url`
            gallery.image.name
            for gallery in package.gallery.all()
        ]

此外，从 PackageGallery 到 Package 的 related_name 应该命名为例如galleries 更好地理解这种关系，因为它是多对一的。

您可以从 ListPackageGallery 中删除 get_queryset 方法，因为我们不需要任何过滤。