BlogJava-没处就黄了-文章分类-SQL

BlogJava-没处就黄了-文章分类-SQLhttp://www.blogjava.net/ieclipse/category/29522.htmlzh-cnWed, 20 Feb 2008 22:17:49 GMTWed, 20 Feb 2008 22:17:49 GMT60SQL语句查询结果由行变为列http://www.blogjava.net/ieclipse/articles/180824.html没处就黄了没处就黄了Wed, 20 Feb 2008 05:33:00 GMThttp://www.blogjava.net/ieclipse/articles/180824.htmlhttp://www.blogjava.net/ieclipse/comments/180824.htmlhttp://www.blogjava.net/ieclipse/articles/180824.html#Feedback0http://www.blogjava.net/ieclipse/comments/commentRss/180824.htmlhttp://www.blogjava.net/ieclipse/services/trackbacks/180824.html 用SQL语句,把表中的数据由行变为列.

查询前:
ID 姓名科目分数
1 张三语文 65
2 张三数学 85
3 张三外语 75
4 李四语文 90
5 李四数学 60
6 李四外语 50

查询后:
姓名语文数学外语
李四 90 60 50
张三 65 85 75

A:
1.先建表.
create table SCORETABLE
(
ID int not null primary key,
NAME varchar(50),
SUBJECT varchar(50),
SCORE int null
);

2.添加数据.
insert into scoretable(ID, NAME, SUBJECT, SCORE) values(1, '张三', '语文', 70);
insert into scoretable(ID, NAME, SUBJECT, SCORE) values(2, '张三', '数学', 85);
insert into scoretable(ID, NAME, SUBJECT, SCORE) values(3, '张三', '外语', 75);
insert into scoretable(ID, NAME, SUBJECT, SCORE) values(4, '李四', '语文', 90);
insert into scoretable(ID, NAME, SUBJECT, SCORE) values(5, '李四', '数学', 60);
insert into scoretable(ID, NAME, SUBJECT, SCORE) values(6, '李四', '外语', 50);

3.用SQL实现.
select NAME as '姓名',
    sum(case SUBJECT when '语文' then SCORE else 0 end) as '语文',
    sum(case SUBJECT when '数学' then SCORE else 0 end) as '数学',
    sum(case SUBJECT when '外语' then SCORE else 0 end) as '外语'
from SCORETABLE
group by NAME

这就做完了.主要就是这个SQL语句.其实很简单.

没处就黄了 2008-02-20 13:33 发表评论

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