给我整无语了,两道SQL加起来90分了,算法就10分,关键是SQL死活过不了,麻烦各位大神帮忙看一下有什么玩意 1. select Sno,Sname,count(distinct if(score < 60 ,Cno,null)) as failedCounts from tb_grade group by Sname,Sno having count(distinct if(score < 60 ,Cno,null)) >= 2 order by Sno desc 这是最开始写的,后来改成了子查询,没用if,全通过了,也不知道这段代码问题出在哪 2. se...