Rails 3的範圍與SQL返回空結果

Question

我有一個運行，並從MySQL返回所需的結果下面的SQL語句：

select event_id, count(*) as num_bookmarks 
from event_connections join events on events.id=event_connections.event_id 
where event_connections.connectiontype = 7 

我試圖創建範圍與此，所以我做了以下。 ..

scope :by_bookmark_count, select("event_id, count(*) as num_bookmarks"). 
          from("event_connections"). 
          joins("join events on events.id=event_connections.event_id where event_connections.connectiontype = 3"). 
          group("event_id") 

當我從控制檯運行我得到這個Event.by_bookmark_count ...

2.1.5 :001 > Event.by_bookmark_count 
    Event Load (12.4ms) SELECT event_id, count(*) as num_bookmarks FROM event_connections join events on events.id=event_connections.event_id where event_connections.connectiontype = 7 GROUP BY event_id 
=> [#<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >, #<Event >... 

請注意SQL是正確的，但沒有結果被返回。我錯過了什麼？

Answer 1

以下是最終爲我工作：

scope :by_bookmark_count, select("events.*, event_id, count(*) as num_bookmarks"). 
          from("event_connections"). 
          joins("join events on events.id=event_connections.event_id where event_connections.connectiontype = 3"). 
          group("event_id")