Question

我有这个数据库架构

CREATE TABLE `exercise_quiz` (
  `exercise_id` int(10) unsigned NOT NULL,
  `quiz_id` int(10) unsigned NOT NULL,
  `user_id` int(10) unsigned NOT NULL,
  `answer` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  PRIMARY KEY (`exercise_id`,`quiz_id`,`user_id`),
  KEY `exercise_quiz_user_id_foreign` (`user_id`),
  KEY `exercise_quiz_quiz_id_foreign` (`quiz_id`),
  CONSTRAINT `exercise_quiz_exercise_id_foreign` FOREIGN KEY (`exercise_id`) REFERENCES `exercises` (`id`) ON DELETE CASCADE,
  CONSTRAINT `exercise_quiz_quiz_id_foreign` FOREIGN KEY (`quiz_id`) REFERENCES `quizzes` (`id`) ON DELETE CASCADE,
  CONSTRAINT `exercise_quiz_user_id_foreign` FOREIGN KEY (`user_id`) REFERENCES `users` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

exercises table

CREATE TABLE `exercises` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `title` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  `body` text COLLATE utf8mb4_unicode_ci NOT NULL,
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  `course_id` int(10) unsigned NOT NULL,
  `score` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `exercises_course_id_foreign` (`course_id`),
  CONSTRAINT `exercises_course_id_foreign` FOREIGN KEY (`course_id`) REFERENCES `courses` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=145 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

quizzes table

CREATE TABLE `quizzes` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `question` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

Example of data in exercise_quiz

如何使用原始SQL或Eloquent检索此方法，以便每个exercise_id都有一行，每个quiz_id的平均答案为一列？

之类的东西

exercise_id ---  avg_quiz_1 ---- avg_quiz_2 ---- avg_quiz_3 ...

复杂的SQL或Eloquent查询

0 个答案: