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', ''),
('aaa', 'physical', ''),
('bbb', 'chinese', '67'),
('bbb', 'math', '75'),
('bbb', 'physical', '');
-- 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;