ruby-on-rails - ActiveRecord 在另一个查询中查询，如 SQL 中的“IN”

Question

我想在 Rails/Active Record 中写这个查询

SELECT *  FROM messages WHERE (realtor_id,created_at) IN  ( SELECT realtor_id, MAX(created_at),message   FROM messages   WHERE `messages`.`user_id` = 8   GROUP BY realtor_id );

我尝试了一些语法，但它不起作用......我认为，解决方案很接近：

@discussions = Message.where(realtor_id: created_at: [Message.where(:user_id => current_user.id).select("realtor_id, MAX(created_at) as created_at").group("realtor_id").order("created_at ASC")])

有人可以帮助我吗？

感谢提前，

F。

Answer 1

您可以创建sql查询并传入

query = "SELECT *  FROM messages WHERE (realtor_id,created_at) IN  ( SELECT realtor_id, MAX(created_at),message FROM messages WHERE `messages`.`user_id` = 8   GROUP BY realtor_id )"

@discussions = ActiveRecord::Base.connection.execute(query)