日期:2014-05-17 浏览次数:20377 次
select 国家, count(distinct 队员号) as 人数 from table2 group by 国家
select b.国家, count(distinct a.队员号) as 人数 from table1 as a inner join table2 as b on a.队员号=b.队员号 group by b.国家