记得在刚进项目组时候，使用oracle数据库，遇到的第一个难题就是行列转换，哈哈，真是菜的一BI，现在使用sqlServer数据库，又遇到了，记录一下，以备后用和帮助后来者。
言归正传：
数据库：sqlServer2008R2 英文版
1.建表：学生表（姓名，学科，成绩）
CREATE TABLE teststudent(
stuname varchar(50) NULL,
subjects varchar(50) NULL,
source int NULL
)
drop table teststudent ;
select * from teststudent ;
delete from teststudent ;
2.准备数据：
insert into teststudent(stuname,subjects,source) values('小明','语文',80);
insert into teststudent(stuname,subjects,source) values('小明','数学',85);
insert into teststudent(stuname,subjects,source) values('小明','英语',90);
insert into teststudent(stuname,subjects,source) values('小红','语文',86);
insert into teststudent(stuname,subjects,source) values('小红','数学',90);
insert into teststudent(stuname,subjects,source) values('小红','英语',85);
insert into teststudent(stuname,subjects,source) values('小亮','语文',99);
insert into teststudent(stuname,subjects,source) values('小亮','数学',99);
insert into teststudent(stuname,subjects,source) values('小亮','英语',100);
3.转换：可以采用max()、sum()两种方式
--方式1：
select stuname ,
MAX(case when subjects = '语文' then source else 0 end ) '语文',
MAX(case when subjects = '数学' then source else 0 end ) '数学',
MAX(case when subjects = '英语' then source else 0 end ) '英语'
from teststudent group by stuname ;
--方式2：
select stuname ,
SUM(case when subjects = '语文' then source else 0 end) '语文',
SUM(case when subjects = '数学' then source else 0 end ) '数学',
SUM(case when subjects = '英语' then source else 0 end ) '英语'
from teststudent group by stuname ;
4.其他待补充