写作与多个Rails 3.2一个简单的SQL查询连接
问题描述:
我需要写在Rails中的SQL查询3.2语法,说:写作与多个Rails 3.2一个简单的SQL查询连接
“给我的任务是属于赛道,visibility_private == false
所有提交”
Track.rb
has_many :missions
attr_accessible :visibility_private
Mission.rb
belongs_to :track
has_many :submissions
Submission.rb
belongs_to :mission
我最初的尝试是这样,但是这肯定是不对的:
Submission.joins(:mission).where(:missions => { mission.track.visibility_private == false })
答
你需要使用类似,
Submission.joins(mission: :track).where("tracks.visibility_private = ?",false)
或
Submission.joins(mission: :track).where(tracks: { visibility_private: false })
希望这会为你工作。
我最初的尝试是这样,但是这肯定是不对的: 'Submission.joins(:任务)。凡(:任务=> {mission.track.visibility_private ==假})' –
尝试'Submission.joins( :mission,:track).where(:mission => {:track => {visibility_private:false}})' – Iceman
也许这个Q/A可以提供帮助:http://*.com/questions/23633301/how-to -query-a-model-based-attribute-of-another-model-which-attributes-to-the-fi/23633352#23633352 – MrYoshiji