基於HABTM的查找無硬編碼SQL片段

Question

訂購habtm設備和設備habtm命令。

我需要找到訂單，讓所有指定的設備

我做如下：

devices = Device.all :conditions => {:name => params[:devices].split(",")} 
@orders = Order.all :joins => :devices, :conditions => {:devices => devices} 

它產生下面的SQL：

SELECT "orders".*

FROM "orders"

INNER JOIN "orders_devices" ON "orders_devices".order_id = "orders".id

INNER JOIN "devices" ON "devices".id = "orders_devices".device_id

WHERE ("orders"."devices" IN (110330561,530240381)) ORDER BY date DESC)

查詢的最後一個字符串爲不正確，當然，我得到一個錯誤：

SQLite3::SQLException: no such column: orders.devices

爲什麼我得到這個結果？

我該如何解決這個問題，而不指定SQL查詢的片段，像：

:conditions => ['devices.id in (?)',[1,2]] 

Answer 1

也許只是這個？

@orders = Order.all(:joins => :devices, :conditions => {"devices.id" => devices})