查询双的has_many：通过关联

Question

我有一个双重的has_many：通过关系是这样的：

class Survey < ActiveRecord::Base 
    has_many :surveyquestions 
    has_many :questions, through: :surveyquestions 
end 

class Question < ActiveRecord::Base 
    has_many :surveyquestions 
    has_many :surveys, through: :surveyquestions 
    has_many :kpiquestions, dependent: :destroy 
    has_many :kpis, through: :kpiquestions 
end 

class Kpi < ActiveRecord::Base 
    has_many :kpiquestions 
    has_many :questions, through: :kpiquestions 
end 

现在我想查询具有特定survey_id和特定kpi_id问题，但我不知道该如何查询这个？

Answer 1

嘿，你可以尝试这样

Question.includes(:surveys,:kpis).where(:surveys => {:survey_id => 1}, :kpis => {:kpi_id => 2})