ruby on rails - ActiveRecord Survey Model ActiveRecord Associations for Doctor -> Patient -

i'm trying build survey form user can select survey template, , form rendered questions specific template.

class survey < activerecord::base   belongs_to :template   belongs_to :patient   has_many :questions, :through=> :template   has_many :answers, :through=> :questions end  class template < activerecord::base     has_many :surveys     has_many :questions end  class question < activerecord::base   belongs_to :template   has_many :answers end   class answer < activerecord::base   belongs_to :question   belongs_to :survey end 

the questions table has list of 30 pre-seeded questions go each template:

  create_table "questions", force: :cascade |t|     t.integer  "template_id"     t.text     "content"     t.string   "field_type"     t.datetime "created_at",  null: false     t.datetime "updated_at",  null: false     t.string   "category"     t.string   "options"     t.boolean  "additional"   end  acl = template.create(name:"acl", body_part:"knee") acl.questions.create(content:"diagnosis", field_type:"text_area", category: "s") 

i can call patient.surveys list of surveys associated patient. can call patient.surveys.first.questions list of questions associated given survey.

but dilemma can't figure out how answer associated specific question specific survey. because it's setup now, each question has multiple answers many different surveys.

ideally able call patient.surveys.first.questions.first.answer specific answer question for survey.

but now, need go patient.surveys.first.questions.first.answers.where(survey_id: survey.first.id)

so question is:

what need adjust in associations can call:

patient.surveys.first.questions.first.answer correct answer associated both question , survey ?

well, first thing note performing multiple queries can pop 1 procedural scope. have no idea big picture needs totally off more important you.

to answer question specifically, can define method in question grabs right answer.

def answer    survey=survey.joins(:templates).where(:templates {id: self.template_id, question_id: self.id}).first    answer.where(:survey_id => survey.id).first end 

then call

patient.surveys.first.questions.first.answer

you can scoping answer directly popping answer model

scope :for_survey_question, lambda {|survey, question| where(:survey_id => survey.id, :question_id => question.id).first } 

and calling anywhere answer.for_survey_question(survey,question) (where survey , question both survey , question model objects loaded , passed in parameters respectively)