但我发现一格问题,如果我的表为:
我有个表,比如:
id date num over
1 2005-10-1 10 Y
2 2005-10-3 3 Y
3 2005-10-3 15 Y
4 2005-10-3 10 N
我想得到下面的查询结果:
id date num over
1 2005-10-1 10 Y
2 2005-10-3 18 Y
我用:
select min(id) as id,[date],sum(num) as num, over
from tt
where (over=yes)
group by [date];
却不行,应该怎么办呢?