SELECT username,sum(tjjs) FROM user where starttime >= '2011-09-28 00:00:00' and starttime <= '2011-09-28 23:59:59' GROUP BY username ================================== username sum 张三 18 李四 15 王五 30 ==================================== 其它sum为NULL的都不显示
user表结构及记录贴出来,SUM忽略NULL
select username,sum(if(starttime >= '2011-09-28 00:00:00' and starttime <= '2011-09-28 23:59:59',tjjs,0)) from user group by username
如果数据量比较大,则考虑使用下面语句。select username,(SELECT sum(tjjs) from user where starttime >= '2011-09-28 00:00:00' and starttime <= '2011-09-28 23:59:59' and username=a.username) from user a group by username
username,sum(tjjs)
FROM
user
where starttime >= '2011-09-28 00:00:00' and starttime <= '2011-09-28 23:59:59' GROUP BY username
==================================
username sum
张三 18
李四 15
王五 30
====================================
其它sum为NULL的都不显示
from user
group by username
from user a
group by username
你真是个奇才,呵呵