name course fenshu
小张 语文 81
小张 数学 75
小李 语文 76
小李 数学 90
小王 语文 81
小王 数学 100
小王 英语 90
select distinct a.name from table a left join (select distinct name from table where fenshu <= 80) b on a.name=b.name where b.name is null;
select name from table where fenshu > 80 group by name having cnt > 0;
select distinct name from table where name in (select distinct name from table where fenshu > 80)
select name,sum(case when fenshu<=80 then 1 else 0 end) scr from table group by name having scr=0;