Question

帖子 has_many upvotes 。列 is_featured 也可以是否有帖子。

我想获得所有精选帖子，按照upvotes（最多到最少）排序，然后是created_at（从最新到最旧）。

以下是我构建查询的方法。＃1和＃2工作，但对于＃3我不能同时按日期和upvotes排序。

# 1. Get all featured posts
Posts.where(is_featured: true) 

# 2. Get all featured posts, sort by their votes in DESC order. Maybe there is an easier way?
Posts.where(is_featured: true).sort_by{|post| post.upvotes.count}.reverse! 

# 3. Get all featured posts, sort by their votes in DESC order, sort by created_at DESC (doesnt work)
Posts.where(is_featured: true).sort_by{|post| post.upvotes.count}.reverse!.sort_by{|post| post.created_at}.reverse!

什么是正确的查询？

Answer 1

我强烈建议您为upvotes实现counter_cache，然后执行：

Posts.where(is_featured: true).order("upvotes_count DESC, created_at DESC")

你upvotes模型应该是这样的

class Upvotes
  belong_to :posts, :counter_cache => true
  ...
end

然后你需要在你的帖子表上使用upvotes_count：整数。

按相关模型计数对记录排序，然后按时间顺序排序

1 个答案: