mysql 将列值转变为列的方法(转)

转自http://www.jb51.net/article/36497.htm

-- 创建库
CREATE TABLE `rate` (
 `uname` VARCHAR (300),
 `object` VARCHAR (300),
 `score` VARCHAR (300)
);   
 -- 插入数据
INSERT INTO test.rate (uname, object, score)
 VALUES('aaa', 'chinese', '67'),
 ('aaa', 'math', '89'),
 ('aaa', 'physical', '89'),
 ('bbb', 'chinese', '67'),
 ('bbb', 'math', '75'),
 ('bbb', 'physical', '89');

			uname	object	score
			aaa	chinese	67
			aaa	math	89
			aaa	physical	89
			bbb	chinese	67
			bbb	math	75
			bbb	physical	89

-- 查询
SELECT DISTINCT uname AS '姓名',
SUM(CASE object
WHEN 'chinese' THEN score END)  AS '语文',
SUM(CASE object
WHEN 'math' THEN score END)  AS '数学',
SUM(CASE object
WHEN 'physical' THEN score END)  AS '物理' FROM rate GROUP BY uname;

姓名	语文	数学	物理
aaa	67	89	89
bbb	67	75	89