[转]Oracle行列转换小结
2013-09-15 10:26
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目录结构如下:
行转列
列转行
[一]、行转列
1.1、初始测试数据
表结构:TEST_TB_GRADE
Sql代码
create table TEST_TB_GRADE
(
ID
NUMBER(10) not null,
USER_NAME VARCHAR2(20
CHAR),
COURSE
VARCHAR2(20 CHAR),
SCORE
FLOAT
)
初始数据如下图:
1.2、 如果需要实现如下的查询效果图:
这就是最常见的行转列,主要原理是利用decode函数、聚集函数(sum),结合group
by分组实现的,具体的sql如下:
Sql代码
select t.user_name,
sum(decode(t.course, '语文', score,null)) as
CHINESE,
sum(decode(t.course, '数学', score,null)) as
MATH,
sum(decode(t.course, '英语', score,null)) as
ENGLISH
from test_tb_grade t
group by t.user_name
order by t.user_name
1.3、延伸
如果要实现对各门功课的不同分数段进行统计,效果图如下:
具体的实现sql如下:
Sql代码
select t2.SCORE_GP,
sum(decode(t2.course, '语文', COUNTNUM,null)) as
CHINESE,
sum(decode(t2.course, '数学', COUNTNUM,null)) as
MATH,
sum(decode(t2.course, '英语', COUNTNUM,null)) as
ENGLISH
from (
select t.course,
case when t.score <60 then
'00-60'
when t.score >=60 and t.score
<80 then
'60-80'
when t.score >=80 then '80-100' end as
SCORE_GP,
count(t.score) as COUNTNUM
FROM test_tb_grade t
group by
t.course,
case when t.score
<60 then
'00-60'
when t.score >=60 and t.score
<80 then
'60-80'
when t.score >=80 then '80-100'
end
order by t.course ) t2
group by t2.SCORE_GP
order by t2.SCORE_GP
[二]、列转行
1.1、初始测试数据
表结构:TEST_TB_GRADE2
Sql代码
create table TEST_TB_GRADE2
(
ID
NUMBER(10) not null,
USER_NAME VARCHAR2(20
CHAR),
CN_SCORE
FLOAT,
MATH_SCORE FLOAT,
EN_SCORE
FLOAT
)
初始数据如下图:
1.2、 如果需要实现如下的查询效果图:
这就是最常见的列转行,主要原理是利用SQL里面的union,具体的sql语句如下:
Sql代码
select user_name, '语文' COURSE , CN_SCORE as SCORE from
test_tb_grade2
union select user_name, '数学' COURSE, MATH_SCORE as SCORE from
test_tb_grade2
union select user_name, '英语' COURSE, EN_SCORE as SCORE from
test_tb_grade2
order by user_name,COURSE
也可以利用【 insert all into ... select
】来实现,首先需要先建一个表TEST_TB_GRADE3:
Sql代码
create table
TEST_TB_GRADE3
(
USER_NAME VARCHAR2(20
CHAR),
COURSE
VARCHAR2(20
CHAR),
SCORE
FLOAT
)
再执行下面的sql:
Sql代码
insert all
into test_tb_grade3(USER_NAME,COURSE,SCORE) values(user_name, '语文',
CN_SCORE)
into test_tb_grade3(USER_NAME,COURSE,SCORE) values(user_name, '数学',
MATH_SCORE)
into test_tb_grade3(USER_NAME,COURSE,SCORE) values(user_name, '英语',
EN_SCORE)
select user_name, CN_SCORE, MATH_SCORE, EN_SCORE from
test_tb_grade2;
commit;
别忘记commit操作,然后再查询TEST_TB_GRADE3,发现表中的数据就是列转成行了。
oracle,行转列,列转行
引自:http://www.2cto.com/database/201108/100792.html
行转列
列转行
[一]、行转列
1.1、初始测试数据
表结构:TEST_TB_GRADE
Sql代码
create table TEST_TB_GRADE
(
ID
NUMBER(10) not null,
USER_NAME VARCHAR2(20
CHAR),
COURSE
VARCHAR2(20 CHAR),
SCORE
FLOAT
)
初始数据如下图:
1.2、 如果需要实现如下的查询效果图:
这就是最常见的行转列,主要原理是利用decode函数、聚集函数(sum),结合group
by分组实现的,具体的sql如下:
Sql代码
select t.user_name,
sum(decode(t.course, '语文', score,null)) as
CHINESE,
sum(decode(t.course, '数学', score,null)) as
MATH,
sum(decode(t.course, '英语', score,null)) as
ENGLISH
from test_tb_grade t
group by t.user_name
order by t.user_name
1.3、延伸
如果要实现对各门功课的不同分数段进行统计,效果图如下:
具体的实现sql如下:
Sql代码
select t2.SCORE_GP,
sum(decode(t2.course, '语文', COUNTNUM,null)) as
CHINESE,
sum(decode(t2.course, '数学', COUNTNUM,null)) as
MATH,
sum(decode(t2.course, '英语', COUNTNUM,null)) as
ENGLISH
from (
select t.course,
case when t.score <60 then
'00-60'
when t.score >=60 and t.score
<80 then
'60-80'
when t.score >=80 then '80-100' end as
SCORE_GP,
count(t.score) as COUNTNUM
FROM test_tb_grade t
group by
t.course,
case when t.score
<60 then
'00-60'
when t.score >=60 and t.score
<80 then
'60-80'
when t.score >=80 then '80-100'
end
order by t.course ) t2
group by t2.SCORE_GP
order by t2.SCORE_GP
[二]、列转行
1.1、初始测试数据
表结构:TEST_TB_GRADE2
Sql代码
create table TEST_TB_GRADE2
(
ID
NUMBER(10) not null,
USER_NAME VARCHAR2(20
CHAR),
CN_SCORE
FLOAT,
MATH_SCORE FLOAT,
EN_SCORE
FLOAT
)
初始数据如下图:
1.2、 如果需要实现如下的查询效果图:
这就是最常见的列转行,主要原理是利用SQL里面的union,具体的sql语句如下:
Sql代码
select user_name, '语文' COURSE , CN_SCORE as SCORE from
test_tb_grade2
union select user_name, '数学' COURSE, MATH_SCORE as SCORE from
test_tb_grade2
union select user_name, '英语' COURSE, EN_SCORE as SCORE from
test_tb_grade2
order by user_name,COURSE
也可以利用【 insert all into ... select
】来实现,首先需要先建一个表TEST_TB_GRADE3:
Sql代码
create table
TEST_TB_GRADE3
(
USER_NAME VARCHAR2(20
CHAR),
COURSE
VARCHAR2(20
CHAR),
SCORE
FLOAT
)
再执行下面的sql:
Sql代码
insert all
into test_tb_grade3(USER_NAME,COURSE,SCORE) values(user_name, '语文',
CN_SCORE)
into test_tb_grade3(USER_NAME,COURSE,SCORE) values(user_name, '数学',
MATH_SCORE)
into test_tb_grade3(USER_NAME,COURSE,SCORE) values(user_name, '英语',
EN_SCORE)
select user_name, CN_SCORE, MATH_SCORE, EN_SCORE from
test_tb_grade2;
commit;
别忘记commit操作,然后再查询TEST_TB_GRADE3,发现表中的数据就是列转成行了。
oracle,行转列,列转行
引自:http://www.2cto.com/database/201108/100792.html