关于SQL查询的问题？急急急！

[skig]

现有一个班，有60名学生，每月数学要月考一次，考试成绩按月存在CJ表里，现在我想查询2006年里连续三个月考试成绩为0的学生名单。如何写SQL语句。cj表有字段为：学号；姓名；月份；成绩。急急，请高手给予解决！在线等

[XqYuan]

select `学号`,`姓名` from
(SELECT `学号`,`姓名`,group_concat(`成绩` order by `月份` SEPARATOR " ") as total from cj group by `学号`) as a
where left(total,6)='0 0 0 ' or right(total,6)=' 0 0 0' or instr(total,' 0 0 0 ')>0

不知道行不行，效率低，还好数据比较少("连续三个月"比较麻烦)

[skig]

(SELECT `学号`,`姓名`,group_concat(`成绩` order by `月份` SEPARATOR " ") as total from cj 是不是先查出所有成绩为0的学生?

[XqYuan]

所有学生当年成绩按月份排序，组成字符串

[「已注销」]

如果可以改动表的话,改改表增加个月份字段(下个月的月份)

学号；月份；下月月份；成绩；姓名；

1 200606 200607 0 aaa
并在月份上建索引。

sql:
select * from cj as a,cj as b,cj as c where a.下月月份=b.月份 and b.下月月份=c.月份 and a.成绩=0 and b.成绩=0 and c.成绩=0;

[「已注销」]

哈，少写了点东西

select * from cj as a inner join cj as b on a.学号=b.学号 and a.下月月份=b.月份 inner join cj as c on b.学号=c.学号 and b.下月月份=c.月份 where a.成绩=0 and b.成绩=0 and c.成绩=0 group by a.学号;