ActiveRecord中的表別名？

Question

我有以下找到職位。

@posts = Post.find(:all, 
:select => "DISTINCT *", 
:include => [:user, {:track => :artist}], 
:conditions => ["user_id IN (?) AND NOT track_id = ?", users, @track.id], 
:group => "track_id", 
:order => 'id desc', 
:limit => '5') 

我想補充的子查詢

(SELECT COUNT(*) FROM posts P2 
    WHERE P2.user_id = P1.user_id AND P2.id > P1.id AND P2.track_id <> 34) 
<= 1 

在我的條件條款，限制每個用戶的職位數目。

如何將別名P1設置爲「初始」帖子表？

使用Rails 2.3.11

Answer 1

您可以添加from參數：

:from => 'posts P1', 

find (ActiveRecord::Base)