So what I want to do, is to rank students based on their weighted average which will be calculated by separating the grades based on the type (whether "exam" or "not exam). The average for both will then be added together to give a total which will be used to do the ranking of the students.
I used the query below but it is not using the right averages as it doesn't group the types correctly. For example.. where it should get the average for all grades that are not exam it also includes exam grades:
SELECT * FROM (SELECT student_id, avg, exam,(exam) + (avg) as total, (@rn := @rn + 1) AS rankFROM (SELECT student_id, ((SELECT AVG(grade) where grades.type != 'exam')/100 * 40 ) as avg, ((SELECT AVG(grade) where type = 'exam')/100 * 60 ) as exam FROM grades WHERE class_id = 1 AND subject_id = 1 GROUP BY student_id ) agg CROSS JOIN (SELECT @rn := 0) CONST ORDER BY total desc) t See a screenshot of the table below:
See the Query to create table below:
Table structure for table grades
CREATE TABLE `grades` ( `grade_id` int(11) NOT NULL, `assessment_id` int(11) NOT NULL, `subject_id` int(11) NOT NULL, `student_id` int(11) NOT NULL, `class_id` int(11) NOT NULL, `grade` double NOT NULL, `teacher_comment` text, `type` enum('Home Work','Class','Unit Test','Assignment','Exam') DEFAULT NULL, `term` enum('1','2','3') DEFAULT NULL, `sch_year` year(4) NOT NULL, `entered_by` int(11) DEFAULT NULL, `enter_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP) ENGINE=InnoDB DEFAULT CHARSET=latin1;---- Dumping data for table `grades`--INSERT INTO `grades` (`grade_id`, `assessment_id`, `subject_id`, `student_id`, `class_id`, `grade`, `teacher_comment`, `type`, `term`, `sch_year`, `entered_by`, `enter_date`) VALUES(1, 1, 3, 10001, 2, 88, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:04:38'),(5, 1, 3, 10001, 2, 80, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:12:17'),(6, 1, 3, 10002, 2, 60, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:12:17'),(7, 1, 3, 10001, 2, 80, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:13:50'),(8, 1, 3, 10002, 2, 75, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:13:50'),(9, 1, 3, 10003, 2, 95, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:13:50'),(10, 1, 3, 10001, 2, 85, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:22:53'),(11, 1, 3, 10002, 2, 88, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:22:53'),(12, 1, 3, 10003, 2, 90, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:22:54'),(13, 1, 3, 10001, 2, 98, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:23:44'),(14, 1, 3, 10002, 2, 95, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:23:44'),(15, 1, 3, 10003, 2, 90, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:23:44'),(16, 1, 3, 10001, 2, 96, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:24:42'),(17, 1, 3, 10002, 2, 88, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:24:42'),(18, 1, 3, 10003, 2, 86, NULL, 'Home Work', '3', 2015, NULL, '2016-06-21 02:24:42'),(22, 3, 4, 10001, 2, 55, NULL, 'Class', '3', 2015, NULL, '2016-06-21 02:27:47'),(23, 3, 4, 10002, 2, 75, NULL, 'Class', '3', 2015, NULL, '2016-06-21 02:27:47'),(24, 3, 4, 10003, 2, 85, NULL, 'Class', '3', 2015, NULL, '2016-06-21 02:27:47'),(25, 4, 3, 10001, 2, 85, NULL, 'Unit Test', '3', 2015, NULL, '2016-06-21 17:41:05'),(26, 4, 3, 10002, 2, 90, 'Test', 'Unit Test', '3', 2015, NULL, '2016-06-21 17:41:05'),(27, 4, 3, 10003, 2, 65, NULL, 'Unit Test', '3', 2015, NULL, '2016-06-21 17:41:05'),(28, 5, 3, 10001, 2, 96, NULL, 'Assignment', '3', 2015, NULL, '2016-06-22 19:10:34'),(29, 5, 3, 10002, 2, 90, 'Test', 'Assignment', '3', 2015, NULL, '2016-06-22 19:10:34'),(30, 5, 3, 10003, 2, 98, NULL, 'Assignment', '3', 2015, NULL, '2016-06-22 19:10:34'),(31, 6, 2, 10001, 2, 55, NULL, 'Exam', '3', 2015, NULL, '2016-06-29 15:04:47'),(32, 6, 2, 10002, 2, 65, 'Test', 'Exam', '3', 2015, NULL, '2016-06-29 15:04:47'),(33, 6, 2, 10003, 2, 60, NULL, 'Exam', '3', 2015, NULL, '2016-06-29 15:04:47'),(34, 10, 3, 10001, 2, 95, NULL, 'Exam', '3', 2015, NULL, '2016-06-30 15:53:34'),(35, 10, 3, 10002, 2, 85, NULL, 'Exam', '3', 2015, NULL, '2016-06-30 15:53:34'),(36, 10, 3, 10003, 2, 90, NULL, 'Exam', '3', 2015, NULL, '2016-06-30 15:53:34'),(37, 9, 1, 10001, 2, 95, NULL, 'Exam', '3', 2015, NULL, '2016-06-30 15:55:20'),(38, 9, 1, 10002, 2, 90, NULL, 'Exam', '3', 2015, NULL, '2016-06-30 15:55:20'),(39, 9, 1, 10003, 2, 93, NULL, 'Exam', '3', 2015, NULL, '2016-06-30 15:55:20'),(40, 12, 2, 10001, 2, 95, NULL, 'Exam', '3', 2015, NULL, '2016-07-11 15:56:34'),(41, 12, 2, 10002, 2, 96, NULL, 'Exam', '3', 2015, NULL, '2016-07-11 15:56:34'),(42, 12, 2, 10003, 2, 90, NULL, 'Exam', '3', 2015, NULL, '2016-07-11 15:56:34'),(43, 11, 3, 10001, 2, 85, NULL, 'Exam', '3', 2015, NULL, '2016-07-11 16:00:22'),(44, 11, 3, 10002, 2, 88, NULL, 'Exam', '3', 2015, NULL, '2016-07-11 16:00:22'),(45, 11, 3, 10003, 2, 92, NULL, 'Exam', '3', 2015, NULL, '2016-07-11 16:00:22'),(46, 13, 4, 10001, 2, 85, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:53'),(47, 13, 4, 10002, 2, 96, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:53'),(48, 13, 4, 10003, 2, 52, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:53'),(49, 13, 4, 10004, 2, 85, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:53'),(50, 13, 4, 10005, 2, 74, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:53'),(51, 13, 4, 10006, 2, 96, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:53'),(52, 13, 4, 10007, 2, 85, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:53'),(53, 13, 4, 10008, 2, 74, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(54, 13, 4, 10009, 2, 58, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(55, 13, 4, 10010, 2, 97, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(56, 13, 4, 10011, 2, 88, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(57, 13, 4, 10024, 2, 96, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(58, 13, 4, 10012, 2, 88, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(59, 13, 4, 10013, 2, 89, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(60, 13, 4, 10014, 2, 54, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(61, 13, 4, 10015, 2, 75, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(62, 13, 4, 10016, 2, 86, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(63, 13, 4, 10017, 2, 57, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(64, 13, 4, 10018, 2, 89, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(65, 13, 4, 10019, 2, 93, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(66, 13, 4, 10020, 2, 99, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(67, 13, 4, 10021, 2, 72, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(68, 13, 4, 10022, 2, 100, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(69, 13, 4, 10023, 2, 85, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(70, 13, 4, 10025, 2, 95, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(71, 13, 4, 10026, 2, 75, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(72, 13, 4, 10027, 2, 75, NULL, 'Unit Test', '1', 0000, NULL, '2016-07-15 22:35:54'),(73, 14, 5, 10001, 2, 85, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(74, 14, 5, 10002, 2, 53, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(75, 14, 5, 10003, 2, 21, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(76, 14, 5, 10004, 2, 88, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(77, 14, 5, 10005, 2, 96, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(78, 14, 5, 10006, 2, 55, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(79, 14, 5, 10007, 2, 75, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(80, 14, 5, 10008, 2, 89, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(81, 14, 5, 10009, 2, 93, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(82, 14, 5, 10010, 2, 99, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(83, 14, 5, 10011, 2, 57, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(84, 14, 5, 10024, 2, 88, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(85, 14, 5, 10012, 2, 75, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(86, 14, 5, 10013, 2, 80, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(87, 14, 5, 10014, 2, 97, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(88, 14, 5, 10015, 2, 95, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(89, 14, 5, 10016, 2, 45, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(90, 14, 5, 10017, 2, 77, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(91, 14, 5, 10018, 2, 88, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(92, 14, 5, 10019, 2, 99, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(93, 14, 5, 10020, 2, 87, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(94, 14, 5, 10021, 2, 57, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:47'),(95, 14, 5, 10022, 2, 85, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:48'),(96, 14, 5, 10023, 2, 75, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:48'),(97, 14, 5, 10025, 2, 82, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:48'),(98, 14, 5, 10026, 2, 78, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:48'),(99, 14, 5, 10027, 2, 99, NULL, 'Class', '1', 0000, NULL, '2016-07-15 22:42:48'),(100, 15, 5, 10001, 2, 86, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(101, 15, 5, 10002, 2, 90, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(102, 15, 5, 10003, 2, 99, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(103, 15, 5, 10004, 2, 55, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(104, 15, 5, 10005, 2, 85, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(105, 15, 5, 10006, 2, 87, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(106, 15, 5, 10007, 2, 86, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(107, 15, 5, 10008, 2, 58, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(108, 15, 5, 10009, 2, 98, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(109, 15, 5, 10010, 2, 75, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(110, 15, 5, 10011, 2, 77, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(111, 15, 5, 10024, 2, 88, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(112, 15, 5, 10012, 2, 86, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(113, 15, 5, 10013, 2, 88, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(114, 15, 5, 10014, 2, 79, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(115, 15, 5, 10015, 2, 98, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:28'),(116, 15, 5, 10016, 2, 83, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(117, 15, 5, 10017, 2, 80, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(118, 15, 5, 10018, 2, 84, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(119, 15, 5, 10019, 2, 86, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(120, 15, 5, 10020, 2, 89, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(121, 15, 5, 10021, 2, 78, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(122, 15, 5, 10022, 2, 89, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(123, 15, 5, 10023, 2, 87, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(124, 15, 5, 10025, 2, 88, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(125, 15, 5, 10026, 2, 99, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(126, 15, 5, 10027, 2, 95, NULL, 'Exam', '1', 0000, NULL, '2016-07-15 22:43:29'),(127, 16, 1, 10028, 1, 85, NULL, 'Home Work', '1', 0000, NULL, '2016-07-15 23:36:33'),(128, 16, 1, 10029, 1, 88, NULL, 'Home Work', '1', 0000, NULL, '2016-07-15 23:36:33'),(129, 16, 1, 10030, 1, 89, NULL, 'Home Work', '1', 0000, NULL, '2016-07-15 23:36:33'),(130, 17, 1, 10028, 1, 90, NULL, 'Class', '1', 0000, NULL, '2016-07-16 04:19:18'),(131, 17, 1, 10029, 1, 95, NULL, 'Class', '1', 0000, NULL, '2016-07-16 04:19:18'),(132, 17, 1, 10030, 1, 96, NULL, 'Class', '1', 0000, NULL, '2016-07-16 04:19:18');---- Indexes for dumped tables------ Indexes for table `grades`--ALTER TABLE `grades` ADD PRIMARY KEY (`grade_id`), ADD KEY `subject_id` (`subject_id`), ADD KEY `student_id` (`student_id`), ADD KEY `class_id` (`class_id`);---- AUTO_INCREMENT for dumped tables------ AUTO_INCREMENT for table `grades`--ALTER TABLE `grades` MODIFY `grade_id` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=133;---- Constraints for dumped tables------ Constraints for table `grades`--ALTER TABLE `grades` ADD CONSTRAINT `grades_ibfk_1` FOREIGN KEY (`student_id`) REFERENCES `student` (`student_id`) ON UPDATE CASCADE;/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
