创建数据库
CREATE TABLE tb_course(
NAME VARCHAR(20), ##姓名
course VARCHAR(20), ##课程
grade INT ##成绩
);
INSERT INTO tb_course (NAME,course,grade) VALUES('tom','JDBC',20);
INSERT INTO tb_course (NAME,course,grade) VALUES('tom','Hibernate',50);
INSERT INTO tb_course (NAME,course,grade) VALUES('tom','Spring',80);
INSERT INTO tb_course (NAME,course,grade) VALUES('marry','JDBC',30);
INSERT INTO tb_course (NAME,course,grade) VALUES('marry','Hibernate',60);
INSERT INTO tb_course (NAME,course,grade) VALUES('marry','Spring',70);
select * from tb_course
转置前
后
SELECT NAME,
SUM(IF(course='JDBC',grade,0)) JDBC,
SUM(IF(course='Hibernate',grade,0)) Hibernate,
SUM(IF(course='Spring',grade,0)) Spring
FROM tb_course GROUP BY NAME;