测验应用程序的Rails关联和数据库设计 [英] Rails Associations and db design for Quiz Application

问题描述

我正在建立这个测验应用程序。我想要它有点复杂。

我已经想出了这个数据库模式。但是我真的很困惑...对我将需要和什么协会感到困惑。

嗯..有一件事要注意的是，当一个测试被创建没有有关候选人人数的资料。所以，我创建了 test_questions 和 candidate_answers 作为单独的表。

请帮助我协会。

解决方案

我们来看看， / p>

 ＃对于问题：
：has_many => ：答案
：belongs_to => ：test_question 
＃问题表应该有test_question_id列
 
＃答案：
：has_many => ：candidate_answers 
：belongs_to => ：问题
＃答案表应该有question_id列
 
 #Test问题：
：has_many => ：问题
：has_many => ：candidate_answers 
：belongs_to => ：test 
＃测试问题表应该有test_id列而不是question_id
 
 #Tests：
：has_many => ：results 
：has_many => ：test_questions 
：has_many => ：候选人，通过=> ：results，：foreign_key => candidate_id#why not？ ^^ 
 
 #Results 
：belongs_to => ：test 
：belongs_to => ：候选人
＃结果表应该有test_id和candidate_id列
 
 #candidate_answers 
：belongs_to => ：候选人
：belongs_to => ：test_question 
：belongs_to => ：answer 
＃candidate_answers表应该有test_question_id，candidate_id和answer_id列
 
 #Candidates 
：has_many => ：candidate_answers 
：has_many => ：results 
：has_many => ：answers_tests，：class_name => test，：through => ：results，：foreign_key => test_id＃再次，为什么不呢？ 
  

随着您提供的信息，这应该做你想要的。 ;）

I am building this quiz application. I want it to be kinda sophisticated.

I have come up with this database schema. But I am really confused.. Confused about what associations I would be needing and stuff.

Well.. one thing to note is, when a test is created there is no information regarding the number of candidates who will take it. So, I created the test_questions and candidate_answers as separate tables.

Please help me with the associations.

解决方案

Let's see, that would be:

# For Questions: 
:has_many => :answers
:belongs_to => :test_question
  # questions table should have the "test_question_id" column

# Answers:
:has_many => :candidate_answers
:belongs_to => :question 
  # Answers table should have the "question_id" column

#Test Questions:
:has_many => :questions
:has_many => :candidate_answers
:belongs_to => :test
  # test questions table should have the "test_id" column but not the "question_id"

#Tests: 
:has_many => :results
:has_many => :test_questions
:has_many => :candidates, :through => :results, :foreign_key => "candidate_id" #why not? ^^

#Results
:belongs_to => :test
:belongs_to => :candidate
  # Results table should have the "test_id" and "candidate_id" columns

#candidate_answers 
:belongs_to => :candidate
:belongs_to => :test_question
:belongs_to => :answer
  # candidate_answers table should have the "test_question_id", "candidate_id" and "answer_id" columns

#Candidates
:has_many => :candidate_answers
:has_many => :results
:has_many => :answered_tests, :class_name => "test", :through => :results, :foreign_key => "test_id" # again, why not?

And with the information you gave, that should do what you want. ;)

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