sql分组统计

select sno,type ,count(type)from table group by sno,type
这是竖的，横的下面
select sno,sum(case when type='a' then 1 else 0 end) as t_a,sum(case when type='b' then 1 else 0 end) as t_b,sum(case when type='c' then 1 else 0 end) as