ActiveRecord表别名

Question

有谁知道是否有可能为ActiveRecord表连接设置别名？

就像是:

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

有任何想法吗？

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")

或者在Rails 3+中

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