mysql 将列值转变为列的方法
内容摘要
复制代码 代码如下:-- 创建库CREATE TABLE `rate` ( `uname` VARCHAR (300), `object` VARCHAR (300), `score` VARCHAR (300));
-- 插入数据INSERT INTO test.rate (uname
-- 插入数据INSERT INTO test.rate (uname
文章正文
复制代码 代码如下:
-- 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');
-- 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;
代码注释