Django extras() - 逻辑/算法

Question

我有一个看起来像这样的：

class Post(models.Model):
    user = models.ForeignKey(Profile, related_name='posts')

    created = models.DateTimeField(auto_now_add=True)
    description = models.CharField(max_length=100, null = True)

这有两个与之相关的模型：

class Comments(models.Model):
    user = models.ForeignKey(Profile, related_name='author')
    post = models.ForeignKey(Post, related_name='posts')


class Likes(models.Model):
    user = models.ForeignKey(Profile, related_name='liker')
    post = models.ForeignKey(Post, related_name='post' )
    created = models.DateTimeField(auto_now_add=True)

    class Meta:
        ordering = ('created',)

现在，逻辑基本上是计算喜欢的数量+随着时间的推移衰减的cmets数量：

likes + comments / now() - post.created

我已经创建了这个逻辑的 sql 版本，现在使用我创建的 django extra：

s = Post.objects.extras(select={'post':'logic here...... WHERE id = %d} % **MISSING PIECE THAT ALLOWS ME TO ITERATE OVER THE POST OBJECTS**)

谁能帮我弄清楚丢失的部分是什么？我尝试使用 Post.objects.all().id，它不起作用，因为它是一个查询集。

感谢任何帮助，cmets 了解更多信息

Answer 1

请允许我将相关名称更改为更有意义的名称

class Post(models.Model):
    user = models.ForeignKey(Profile, related_name='posts')

class Comments(models.Model):
    user = models.ForeignKey(Profile, related_name='comments')
    post = models.ForeignKey(Post, related_name='comments')

class Likes(models.Model):
    user = models.ForeignKey(Profile, related_name='likes')
    post = models.ForeignKey(Post, related_name='likes' )

现在你可以做

post = Post.objects.get(pk=1)
output = ( post.likes.all().count() + post.comments.all().count() ) / ( now() - post.created )

更新

class Post(models.Model):
    created_at = models.DateTimeField(auto_now_add=True)

    def output(self):
        return ( self.likes.all().count() + self.comments.all().count() ) / (datetime.datetime.now() - self.created_at).total_seconds()

thelist = sorted(Post.objects.all(), key: lambda p : p.output)

据我所知，您无法根据与数据库不直接相关的内容对列表进行排序。因此，根据需要获取信息，并在 Python 中对其进行排序。