複雜的SQL與多個內部聯接和與軌

Question

我想知道如果有可能寫出像這樣一個Rails的Active Record的幫手非常複雜的SQL（號將變量後代替）數：

SELECT 
photographs.id, 
(COUNT(distinct comments.id)/50.0 * 100 * 0.25) + (15 * 0.1) + (COUNT(distinct likes.id)/100.0 * 100 * 0.05) +(COUNT(distinct likes.id)/COUNT(distinct views.id) * 100 * 0.4) +(COUNT(distinct likes.id) * 2.4/100.0 * 0.2) AS FINAL_RANKING 
FROM photographs 
INNER JOIN comments 
ON photographs.id = comments.photograph_id 
INNER JOIN likes 
ON photographs.id = likes.photograph_id 
INNER JOIN views 
ON photographs.id = views.photograph_id 
GROUP BY photographs.id 
ORDER by FINAL_RANKING DESC; 

我在Rails doc上找到了更簡單的例子或簡單的多內連接，但沒有計數

Answer 1

Rails在select命令中接受SQL。

見Active Record Query Interface | Selecting Specific Fields

像這樣的東西應該爲你工作：

Photographs.joins(:comments, :likes, :views, :users).where(
"users.id = 1").select("COUNT(whatever)") 

實際運行無保障。