MySQL DB for exam (test quizzes) 查询分数

Question

我有一个数据库，其中存储了一个包含用户信息的表、一个包含测试(答案和分数)的表以及一个包含用户对每个问题的答案的表。每题总计1分，可以有一个或多个正确答案。如果所有的答案都是正确的，而用户只检查了一个，他将只得到 0.25 分。 我想查询每个用户的总分，但我没有找到好的方法。

用户表:

+--------+------------+-----------+-------------------+------------+--------+
| userID | first_name | last_name | email             | password   | points |
+--------+------------+-----------+-------------------+------------+--------+
|      1 | Jhon       | Jhonny    | jhon@yahoo.com    | secretPass |      0 |
|      2 | Dan        | Dan       | dan@yahoo.com     | 1234       |      0 |
|      3 | Dick       | Pop       | dd@yahoo.com      | 123456     |      0 |
|      4 | Mihaela    | Micky     | mihaela@yahoo.com | pass12     |      0 |
+--------+------------+-----------+-------------------+------------+--------+

问题表: (1 表示答案很好——我们可以有多个正确答案)

+------------+--------------------------------------------------+---+---+---+---+
| questionID | question                                         | a | b | c | d |
+------------+--------------------------------------------------+---+---+---+---+
|          1 | which of these are colors?                       | 1 | 0 | 0 | 1 |
|          2 | which of these are fruits?                       | 1 | 1 | 1 | 0 |
|          3 | which of these are programming language?         | 0 | 1 | 1 | 0 |
|          4 | What is IPv6?                                    | 0 | 0 | 0 | 1 |
+------------+--------------------------------------------------+---+---+---+---+

用户的答案表:(1表示用户选择了那个答案但可能不正确)

+------------+--------+---+---+---+---+
| questionID | userID | a | b | c | d |
+------------+--------+---+---+---+---+
|          1 |      1 | 1 | 1 | 0 | 0 |
|          2 |      1 | 1 | 1 | 1 | 0 |
|          1 |      3 | 1 | 0 | 1 | 1 |
|          1 |      4 | 1 | 1 | 1 | 0 |
|          3 |      1 | 1 | 0 | 1 | 1 |
|          4 |      1 | 1 | 0 | 1 | 1 |
|          1 |      2 | 1 | 1 | 0 | 0 |
|          2 |      2 | 0 | 1 | 0 | 1 |
|          3 |      2 | 0 | 1 | 1 | 1 |
|          4 |      2 | 1 | 1 | 0 | 1 |
|          2 |      3 | 1 | 0 | 0 | 1 |
|          3 |      3 | 1 | 0 | 1 | 1 |
|          4 |      3 | 1 | 0 | 1 | 1 |
|          2 |      4 | 0 | 1 | 1 | 1 |
|          3 |      4 | 1 | 0 | 0 | 1 |
|          4 |      4 | 0 | 0 | 1 | 0 |
+------------+--------+---+---+---+---+

Answer 1

试试这个

SELECT 
  a.*,
  u.name,
  q.*,
  # (a.a & q.a) + (a.b & q.b) + (a.c & q.c) + (a.d & q.d) userCorrects,
  # (a.a + a.b + a.c + a.d) questionCorrects,
  ((a.a & q.a) + (a.b & q.b) + (a.c & q.c) + (a.d & q.d)) / (a.a + a.b + a.c + a.d) as userGrade
FROM
 answer a
    INNER JOIN
 user u ON a.userID = u.id
    INNER JOIN
 question q ON a.questionID = q.id