mysql中一张（居民）表按年龄段查询数据

Posted 2020-10-27 shuaiflying

知识点：

    用mysql,按年龄段查询一张居民的数据（各年龄段居民的个数）

 

 

1.如：查询resident(居民表)，按照各年龄段，统计人数

2.mysql语句如下：

select ageproportion as \'年龄段\',count(*) as \'人数\' from
(
     SELECT
     CASE
       when age>0 and age<=10 then \'0-10岁\'
       when age>10 and age<=20 then \'10-20岁\'
       when age>20 and age<=30 then \'20-30岁\'
       when age>30 and age<=40 then \'30-40岁\'
       when age>40 and age<=50 then \'40-50岁\'
       when age>50 and age<=60 then \'50-60岁\'
       else \'60岁以上\'
      
     END
     as ageproportion from resident
)a GROUP BY ageproportion 

 

3.查询结果：