sql 统计某一字段等于不同值的个数(转)
比如有这一张表t,数据如下
id????? type
001???? 1
001???? 0
002???? 1
001???? 0
002???? 0
001???? 1
001???? 0
002???? 0
现在要统计不同id，type分别为0的,1的个数，查询语句如下
select?
id,sum(case when type=0 then 1 else 0 end) as 0,sum(case when type=1 then 1 else 0 end) as 1?
from t?
group by id?
查询结果如下
id???? 0??? 1
001??? 3??? 2
002??? 2??? 1
