我有這種模型，我想按blog_views屬性訂購，如何最好地做到這一點。
這是模型：
class Post(TimeStampedModel, models.Model):
"""Post model."""
title = models.CharField(_('Title'), max_length=100, blank=False,
null=False)
# TODO: Add image upload.
image = models.ImageField(_('Image'), upload_to='blog_images', null=True,
max_length=900)
body = models.TextField(_('Body'), blank=False)
description = models.CharField(_('Description'), max_length=400,
blank=True, null=True)
slug = models.SlugField(default=uuid.uuid4(), unique=True, max_length=100)
owner = models.ForeignKey(User, related_name='posts',
on_delete=models.CASCADE)
bookmarks = models.ManyToManyField(User, related_name='bookmarks',
default=None, blank=True)
address_views = models.ManyToManyField(CustomIPAddress,
related_name='address_views',
default=None, blank=True)
likes = models.ManyToManyField(User, related_name='likes', default=None,
blank=True,
)
class Meta:
ordering = ['-created']
def __str__(self):
"""
Returns a string representation of the blog post.
"""
return f'{self.title} {self.owner}'
@property
def blog_views(self):
"""Get blog post views."""
return self.address_views.all().count()
我閱讀了annotate但無法獲得清晰的圖片，我該如何在我看來制定這一點。
class PostList(generics.ListCreateAPIView):
"""Blog post lists"""
queryset = Post.objects.all()
serializer_class = serializers.PostSerializer
authentication_classes = (JWTAuthentication,)
permission_classes = (PostsProtectOrReadOnly, IsMentorOnly)
filter_backends = [filters.SearchFilter, filters.OrderingFilter]
search_fields = ['title', 'body',
'tags__name', 'owner__email',
'owner__username'
]
我想按 URL 中的屬性過濾
uj5u.com熱心網友回復：
您不能按方法欄位排序，因為排序是在資料庫級別完成的，而資料庫不知道該欄位存在。
但是你可以annotate像這樣使用：
from django.db.models import Count
class PostList(generics.ListCreateAPIView):
...
queryset = Post.objects.annotate(address_views_count=Count('address_views')).order_by('address_views_count')
如果您希望訂購是可選的，您可以使用filter_queryset：
class PostList(generics.ListCreateAPIView):
def filter_queryset(self, request, queryset, view):
ordering = self.request.GET.get("ordering", None)
if ordering == 'blog_views':
queryset = queryset.annotate(address_views_count=Count('address_views')).order_by('address_views_count')
return queryset
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標籤：Python 蟒蛇-3.x 姜戈 Django 休息框架
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