Question

我有3个表-一个模型QuizResult，一个模型QuizAnswers，然后是它们的可联结表（quiz_answer_quiz_results）：

class QuizResult < ActiveRecord::Base
    has_and_belongs_to_many :quiz_answers, :join_table => :quiz_answer_quiz_results
    belongs_to :quiz
    has_many :quiz_questions, through: :quiz_answers
end

class QuizAnswer < ActiveRecord::Base
  belongs_to :quiz_question
  has_and_belongs_to_many :quiz_results, :join_table => :quiz_answer_quiz_results
end

我希望能够通过搜索归因的quiz_answer_ids来找到QuizResult，但即使通过sql语法，我也无法弄清这种关系。

如果我问QuizResult.first.answer_ids，则朝相反的方向前进，得到[5,9）：

QuizResult.first.quiz_answer_ids
  QuizResult Load (2.0ms)  SELECT "quiz_results".* FROM "quiz_results" ORDER BY "quiz_results"."id" ASC LIMIT 1
   (4.2ms)  SELECT "quiz_answers".id FROM "quiz_answers" INNER JOIN "quiz_answer_quiz_results" ON "quiz_answers"."id" = "quiz_answer_quiz_results"."quiz_answer_id" WHERE "quiz_answer_quiz_results"."quiz_result_id" = $1  [["quiz_result_id", 1]]
 => [5, 9]

已为我想做的事情quiz_answer_ids 5,9如何获取QuizResult对象？我一直在尝试各种奇怪的QuizResult.joins（：quiz_answers）或sql查询，但无济于事。

Answer 1

尝试：

QuizResult.includes(:quiz_answers).where(quiz_answers: { id: [5,9] })

RoR查找HABTM通过多个ID联接

1 个答案: