ActiveRecord表别名

Question

有没有人知道是否可以为ActiveRecord表连接设置别名？

类似的东西：

User.find(:all, :alias => "Users as u", :joins => "Friends as f", :select => "u.id,f.name")

有什么想法吗？

Answer 1

是的，但如果覆盖连接，则需要包含'ON'语句和join语句。

User.find(:all, :joins => " as u INNER JOIN Friends as f ON f.user_id = u.id", :select => "u.id,f.name")

或在Rails 3 +

中

User.joins("as u INNER JOIN Friends as f on f.user_id = u.id")
    .select("u.id, f.name")
    .all