php - Mysql查询基于列匹配

Question

我不知道如何用 mysql 做这个，我只知道如何做基本查询，我想显示一个基于匹配的结果列表，结果将根据答案的相同值显示...answers可能有 1-10 的值

+++++++++++++++TABLE++++++++++++

id  | userName | answer1 | answer2 | answer3 | answer4….

10    Jhon       1        1         3          8

11    Anne       1        2         4          8

12    Mike       7        4         5          7

etc…
++++++++++++++++++++++++++++++++++++++++

如果我在查询中发送值，我希望检查答案并显示对匹配项进行排序的结果， 更多的比赛首先......最后没有比赛

所以如果我发送结果:

answer1=1  answer2=1 answer3=7 answer4=2...

结果应该是(返回id)

10 11 12

Answer 1

你的表设计的不好，你应该把它分成用户表和问题表。

如果您无法更改表设计，您可以使用以下查询解决问题:

select
  id,
  username,
  if(answer1 = :an1, 1, 0) + if(answer2 = :an2, 1, 0) + if(answer3 = :an3, 1, 0) + if(answer4 = :an4, 1, 0) as total
from
  table
order by total desc

更新: 针对此问题的更好设计:

检查 SQLFiddle:http://sqlfiddle.com/#!9/6c145/2现场演示。

1. 创建用户表

   CREATE TABLE users (
       id INT AUTO_INCREMENT PRIMARY KEY,
       username VARCHAR(50) NOT NULL
   );
   

2. 创建问题表

   CREATE TABLE questions (
       id INT PRIMARY KEY,
       correct_answer INT NOT NULL
   );
   

3. 创建用户答案表

    CREATE TABLE user_answers (
        user_id INT,
        question_id INT,
        user_answer TINYINT,
        PRIMARY KEY (user_id, question_id),
        FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE NO   ACTION ON UPDATE NO ACTION,
        FOREIGN KEY (question_id) REFERENCES questions (id) ON DELETE NO ACTION ON UPDATE NO ACTION
    );
   

比起检索数据，您可以使用查询:

SELECT
    tmp.id,
    tmp.username,
    sum(tmp.is_correct) as total
FROM (
    SELECT
        users.id,
        users.username,
        IF (questions.correct_answer = user_answers.user_answer, 1, 0) as is_correct
    FROM
        users
        INNER JOIN user_answers on users.id = user_answers.user_id
        INNER JOIN questions on user_answers.question_id = questions.id
) tmp
GROUP BY tmp.id, tmp.username
ORDER BY total desc;