mysql 将列值转变为列的方法
编程学习 2021-07-05 15:27www.dzhlxh.cn编程入门
应同学的请求，写个将列值转变为列的sql语句，记录一下。
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;