mysql练习

create table STUDENT_SCORE
(
name VARCHAR(20),
subject VARCHAR(20),
score int(10)
);

insert into student_score (NAME, SUBJECT, SCORE) values ('张三', '语文', 78.0);
insert into student_score (NAME, SUBJECT, SCORE) values ('张三', '数学', 88.0);
insert into student_score (NAME, SUBJECT, SCORE) values ('张三', '英语', 98.0);
insert into student_score (NAME, SUBJECT, SCORE) values ('李四', '语文', 89.0);
insert into student_score (NAME, SUBJECT, SCORE) values ('李四', '数学', 76.0);
insert into student_score (NAME, SUBJECT, SCORE) values ('李四', '英语', 90.0);
insert into student_score (NAME, SUBJECT, SCORE) values ('王五', '语文', 99.0);
insert into student_score (NAME, SUBJECT, SCORE) values ('王五', '数学', 66.0);
insert into student_score (NAME, SUBJECT, SCORE) values ('王五', '英语', 91.0);

sql1、实现下列功能

方法一、

select name,
 sum(case subject when '语文' then score end) as '语文',
sum(case subject when '数学' then score end) as '数学',
sum(case subject when '英语' then score end) as '英语'
from student_score 
 group by name;

方法二、

select t1.name "姓名",t1.score "语文",t2.score "数学",t3.score "英语" from (select name,score from student_score where subject="语文") t1,(select name,score from student_score where subject="数学") t2,(select name,score from student_score where subject="英语") t3 where t1.name=t2.name and t1.name=t3.name;