时间:2021-07-01 10:21:17 帮助过:1893人阅读
1.新建一个名为TEST表 2.向TEST表中添加数据 INSERT INTO TEST(STUDENT,COURSE,SCORE) select '张三','语文',78 from dual union select '张三','数学',87 from dual union select '张三','英语',82 from dual union select '张三','物理',90 from dual unio
1.新建一个名为TEST表
2.向TEST表中添加数据
INSERT INTO TEST(STUDENT,COURSE,SCORE)
select '张三','语文',78 from dual union
select '张三','数学',87 from dual union
select '张三','英语',82 from dual union
select '张三','物理',90 from dual union
select '李四','语文',65 from dual union
select '李四','数学',77 from dual union
select '李四','英语',65 from dual union
select '李四','物理',85 from dual
表数据如下:
3.列转行
方法··1:
select
Student,
sum(decode(Course, '数学', Score)) 数学,
sum(decode(Course, '物理', Score)) 物理,
sum(decode(Course, '英语', Score)) 英语,
sum(decode(Course, '语文', Score)) 语文
from
TEST
group by Student
方法··2:
select
Student,
sum(case Course when '数学' then Score else null end) 数学,
sum(case Course when '物理' then Score else null end) 物理,
sum(case Course when '英语' then Score else null end) 英语,
sum(case Course when '语文' then Score else null end) 语文
from
TEST
group by Student
效果如下:
注:sum是求和的意思;比如说里面记录里面有两条张三,列转行显示的结果就会是两个张三的结果之和。