php - MySQL PHP 顺序

Question

我正在编写 MySQL 查询以对此类数据进行排序

Traffic
100/40
12/1
50/20
25/5

从左侧数字中除以右侧数字得到的值。

我也有多列进行排序

前任 - SELECT * FROM fltable ORDER BY Traffic DESC,Speed ASC,Cost ASC

我需要对这些数据进行升序和降序排序，任何人都可以帮我解决这个问题。

谢谢

Answer 1

SELECT * FROM fractions;
+-----------+
| fractions |
+-----------+
| 100/40    |
| 12/1      |
| 25/5      |
| 50/20     |
+-----------+

SELECT fractions
     , SUBSTRING_INDEX(fractions,'/',1)/SUBSTRING_INDEX(fractions,'/',-1)x 
  FROM fractions 
 ORDER 
    BY x DESC;
+-----------+------+
| fractions | x    |
+-----------+------+
| 12/1      |   12 |
| 25/5      |    5 |
| 100/40    |  2.5 |
| 50/20     |  2.5 |
+-----------+------+

Answer 2

尝试类似以下查询：

SELECT *, CONVERT(SUBSTR(var, 1, POSITION('/' IN var) - 1), UNSIGNED INTEGER) as num 
FROM table 
ORDER BY num DESC

/使用SUBSTR和CONVERT到之前获取数字int

结果与num列

100
50
25
12