MySQL轮流排序 [英] MySQL Sorting by turns

问题描述

我要按以下顺序对以下数据项进行排序:

I want to sort the following data items in the order they are presented below :

id | res
--------
1     A
2     A
3     A
4     A
5     A
6     B
7     B
8     B
9     B
10    B
11    C
12    C
13    C
14    C
15    C

我想要的输出是:

res
---
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

有什么技巧可以使它更正确地排序?

Any tricks to make it sort more properly?

非常感谢！

推荐答案

您可以按组中的等级"排序.可以使用自连接并计算具有较小ID的条目来计算排名.

You can order by the "rank" within the group. The rank can be calculated using a self join and counting the entries with lesser ids.

select t1.id, t1.res
from mytable t1
join mytable t2
  on  t2.res = t1.res
  and t2.id <= t1.id
group by t1.id, t1.res
order by count(*), t1.res

http://rextester.com/ICHZNN18920

这篇关于MySQL轮流排序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！