2011-06-06 29 views

回答

0

試着這麼做:

User.find(:all, 
      :joins => 'LEFT JOIN flags ON users.flag_id=flags.id', 
      :group => 'users.id', 
      :having => 'flags.id IS NULL') 
+0

這是我結束了對Rails 3:User.joins( 'LEFT JOIN標誌ON users.id = flags.flaggable_id AND flags.flaggable_type = 「用戶」' ).where('flags.id IS NULL') – 2011-06-06 09:53:39