select 学号,max(if(试卷id=1,成绩,0)) as 成绩1, ..., max(if(试卷id=5,成绩,0)) as 成绩5 from tt group by 学号
SELECT id, sum(if(试卷id=1,87,0) as 成绩1, sum(if(试卷id=2,89,0) as 成绩2, sum(if(试卷id=3,93,0) as 成绩3, sum(if(试卷id=4,83,0) as 成绩4, sum(if(试卷id=5,89,0) as 成绩5 from tb group by id
http://blog.csdn.net/acmain_chm/article/details/4283943 MySQL交叉表 在某些数据库中有交叉表,但在MySQL中却没有这个功能,但网上看到有不少朋友想找出一个解决方法,特发贴集思广义。http://topic.csdn.net/u/20090530/23/0b782674-4b0b-4cf5-bc1a-e8914aaee5ab.html?96198现整理解法如下:数据样本: create table tx( id int primary key, c1 c...
...,
max(if(试卷id=5,成绩,0)) as 成绩5
from tt group by 学号
sum(if(试卷id=1,87,0) as 成绩1,
sum(if(试卷id=2,89,0) as 成绩2,
sum(if(试卷id=3,93,0) as 成绩3,
sum(if(试卷id=4,83,0) as 成绩4,
sum(if(试卷id=5,89,0) as 成绩5
from
tb
group by id
MySQL交叉表
在某些数据库中有交叉表,但在MySQL中却没有这个功能,但网上看到有不少朋友想找出一个解决方法,特发贴集思广义。http://topic.csdn.net/u/20090530/23/0b782674-4b0b-4cf5-bc1a-e8914aaee5ab.html?96198现整理解法如下:数据样本: create table tx( id int primary key, c1 c...
你是牛人啊,谢谢,group_concat出来的数据是返回数组还是返回字符串?
到时合并的时候group_concat()就有数据填充。