如何在mysql中将一行转换为两列?

Please don't make it flag (it's not duplicate) i search it on google can't find any answer.

请不要使它标记(它不是重复的)我在谷歌上搜索它找不到任何答案。

I have below result in mysql

下面是mysql。

|18-30 | 30 - 45 | 45 - 60 | 60+  
|  28  |  26     |   12    | 5

I want it like following result-

我想要的结果是-

|18-30 |  28 |   
|30 -45|  26 |   
|45-60 |  12 |  
| 60+  |  5  |

How i can get it in mysql?

我怎么用mysql呢?

1 个解决方案

#1

The simplest way is union all:

最简单的办法就是团结一致:

select '18-30' as range, `18-30` as val from t union all
select '30 - 45', `18-30` from t union all
select '45 - 60', `45 - 60` from t union all
select '60+',  `60+`;

However, your results are probably coming from a conditional aggregation. I would expect that you can do something like this instead:

然而，您的结果可能来自一个条件聚合。我希望你能做这样的事情:

select (case when age < 30 then '18-29'
             when age < 45 then '30-44'
             when age < 60 then '45-59'
             else '60+'
        end) as agegrp,
       count(*)
from . . .
where age >= 18
group by agegrp;
order by min(age)

#1