sql语句列转行

Posted 2023-05-08

有表table 字段值如下：
字段 A B C D E
值 1 2 3 4 5
需转成如下格式
A 1
B 2
C 3
D 4
E 5
求SQL语句写法

我整理的行转列的问题：

--创建tb表
create table tb(姓名 varchar(10) , 课程 varchar(10) , 分数 int)
insert into tb values('张三' , '语文' , 74)
insert into tb values('张三' , '数学' , 83)
insert into tb values('张三' , '物理' , 93)
insert into tb values('李四' , '语文' , 74)
insert into tb values('李四' , '数学' , 84)
insert into tb values('李四' , '物理' , 94)
go

select * From tb

--SQL SERVER 2000静态行转列
select 姓名 as 姓名 ,
max(case 课程 when '语文' then 分数 else null end) 语文,
max(case 课程 when '数学' then 分数 else null end) 数学,
max(case 课程 when '物理' then 分数 else null end) 物理
from tb
group by 姓名

--SQL SERVER 2000 动态SQL,指课程不止语文、数学、物理这三门课程。(以下同)
declare @sql varchar(8000)
set @sql = 'select 姓名 '
select @sql = @sql + ' , max(case 课程 when ''' + 课程 + ''' then 分数 else 0 end) [' + 课程 + ']'
from (select distinct 课程 from tb) as a
set @sql = @sql + ' from tb group by 姓名'
exec(@sql) 

--SQL SERVER 2005 静态SQL。
select * from (select * from tb) a pivot (max(分数) for 课程 in (语文,数学,物理)) b

--SQL SERVER 2005 动态SQL。
declare @sql varchar(8000)
select @sql = isnull(@sql + '],[' , '') + 课程 from tb group by 课程
set @sql = '[' + @sql + ']'
exec ('select * from (select * from tb) a pivot (max(分数) for 课程 in (' + @sql + ')) b')

 希望对你的学习有帮助。

参考技术A 主要应用case语句来解决行转列的问题
行转列问题主要分为两类
1)简单的行转列问题:
示例表:
id sid course result
1 2005001 语文 80.0
2 2005001 数学 90.0
3 2005001 英语 80.0
4 2005002 语文 56.0
5 2005002 数学 69.0
6 2005002 英语 89.0
执行
select sid,语文=isnull(sum(case course when '语文' then result end),0),
数学=isnull(sum(case course when '数学' then result end),0),
英语=isnull(sum(case course when '英语' then result end),0)
from result
group by sid
order by sid

得出结果
sid 语文 数学 英语
2005001 80.0 90.0 80.0
2005002 56.0 69.0 89.0 参考技术B select 'A',A from table union all
select 'B', B from table union all
select 'C', C from table union all
select 'D',D from table union all
select 'E',E from table
遇到行列转换的问题第一反应就是 uinon all本回答被提问者采纳 参考技术C 用union可以解决：
select 'A' as '字段名 ',A from MyTable union select 'B', B from MyTable union select 'C', C from MyTable union select 'D',D from MyTable union select 'E',E from MyTable

sql 行转列 列转行

1、行转列一般通过case when语句来实现。

create table studentscores(
    username varchar(20),
    subject varchar(30),
    score float
);
insert into studentscores select ‘Nick‘,‘语文‘,80;
insert into studentscores select ‘Nick‘,‘数学‘,90;
insert into studentscores select ‘Nick‘,‘英语‘,70;
insert into studentscores select ‘Nick‘,‘生物‘,85;
insert into studentscores select ‘Kent‘,‘语文‘,80;
insert into studentscores select ‘Kent‘,‘数学‘,90;
insert into studentscores select ‘Kent‘,‘英语‘,70;
insert into studentscores select ‘Kent‘,‘生物‘,85;

select username,
 max(case subject when ‘语文‘ then score else 0 end) as ‘语文‘,
 max(case subject when ‘数学‘ then score else 0 end) as ‘数学‘,
 max(case subject when ‘英语‘ then score else 0 end) as ‘英语‘,
 max(case subject when ‘生物‘ then score else 0 end) as ‘生物‘
from studentscores
GROUP BY username;

 

create table inpours
(
    id int primary key AUTO_INCREMENT,
    username varchar(20),
    createtime datetime,
    paytype varchar(20),
    money decimal,
    issuccess bit
);

insert into inpours select 1,‘张三‘,‘2010-05-01‘,‘支付宝‘,50,1;
insert into inpours select 2,‘张三‘,‘2010-06-14‘,‘支付宝‘,50,1;
insert into inpours select 3,‘张三‘,‘2010-06-14‘,‘手机短信‘,100,1;
insert into inpours select 4,‘李四‘,‘2010-06-14‘,‘手机短信‘,100,1;
insert into inpours select 5,‘李四‘,‘2010-07-14‘,‘支付宝‘,100,1;
insert into inpours select 6,‘王五‘,‘2010-07-14‘,‘工商银行卡‘,100,1;
insert into inpours select 7,‘赵六‘,‘2010-07-14‘,‘建设银行卡‘,100,1;

select createtime,
 case paytype when ‘支付宝‘ then sum(money) else 0 end as ‘支付宝‘,
 case paytype when ‘手机短信‘ then sum(money) else 0 end as ‘手机短信‘,
 case paytype when ‘工商银行卡‘ then sum(money) else 0 end as ‘工商银行卡‘,
 case paytype when ‘建设银行卡‘ then sum(money) else 0 end as ‘建设银行卡‘
from inpours
group by createtime,paytype;

2、列转行，主要是通过UNION ALL，MAX来实现

create table progrectdetail(
    progrectname varchar(20),
    overseasupply int,
    nativesupply int,
    southsupply int,
    northsupply int
);

insert into progrectdetail select ‘A‘,100,200,50,50
union ALL
select ‘B‘,200,300,150,150
union ALL
select ‘C‘,159,400,20,320
union ALL
select ‘D‘,250,30,15,15;

select progrectname,‘OverseaSupply‘ as supplier,
max(overseasupply) as ‘supplynum‘
from progrectdetail
GROUP BY progrectname
union ALL
select progrectname,‘nativesupply‘ as supplier,
max(nativesupply) as ‘supplynum‘
from progrectdetail
GROUP BY progrectname
union ALL
select progrectname,‘southsupply‘ as supplier,
max(southsupply) as ‘supplynum‘
from progrectdetail
GROUP BY progrectname
union ALL
select progrectname,‘northsupply‘ as supplier,
max(northsupply) as ‘supplynum‘
from progrectdetail
GROUP BY progrectname;