Question

鉴于以下模型：

Thread (id, title, timestamps)
ThreadParticipant (id, thread_id, user_id, read(boolean), timestamps)
Comment (id, thread_id, user_id)

如何在返回的地方构造查询：最近的线程注释（Thread.comment.first）等于current_user的所有线程？

...返回最后一个comment.user_id == current_user.id？

的线程

想法？

Answer 1

尝试类似[未经测试的代码]：

Thread.find_by_sql(["Select * from Threads where ((select user_id from comments where threads.id = comments.thread_id ORDER by created_at DESC LIMIT 1) = ?)", current_user.id ])

或尝试一下（不确定是否要求不同会自动选择第一个，但我猜它应该）：

 Thread.find(:all, :joins => :comments , :select => ["distinct threads.id"], :conditions => ["comments.user_id = ?", current_user.id])

查询基于嵌套资源Y返回Model X.

1 个答案: