有一张表结构如下:
id name type
1 li 1
2 liu 1
3 wang 2
4 ping 2
5 wen 2
想得到如下结果
id name type
1,2 li,liu 1
3,4,5 wang,ping,wen 2
这样的SQL语句该怎么写呢,谢谢!
id name type
1 li 1
2 liu 1
3 wang 2
4 ping 2
5 wen 2
想得到如下结果
id name type
1,2 li,liu 1
3,4,5 wang,ping,wen 2
这样的SQL语句该怎么写呢,谢谢!
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3--合并处理
--定义结果集表变量
DECLARE @t TABLE(col1 varchar(10),col2 varchar(100))--定义游标并进行合并处理
DECLARE tb CURSOR LOCAL
FOR
SELECT col1,col2 FROM tb ORDER BY col1,col2
DECLARE @col1_old varchar(10),@col1 varchar(10),@col2 int,@s varchar(100)
OPEN tb
FETCH tb INTO @col1,@col2
SELECT @col1_old=@col1,@s=''
WHILE @@FETCH_STATUS=0
BEGIN
IF @col1=@col1_old
SELECT @s=@s+','+CAST(@col2 as varchar)
ELSE
BEGIN
INSERT @t VALUES(@col1_old,STUFF(@s,1,1,''))
SELECT @s=','+CAST(@col2 as varchar),@col1_old=@col1
END
FETCH tb INTO @col1,@col2
END
INSERT @t VALUES(@col1_old,STUFF(@s,1,1,''))
CLOSE tb
DEALLOCATE tb
--显示结果并删除测试数据
SELECT * FROM @t
DROP TABLE tb
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
GO
/*==============================================*/
--3.3.2 使用用户定义函数,配合SELECT处理完成字符串合并处理的示例
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3
GO--合并处理函数
CREATE FUNCTION dbo.f_str(@col1 varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+CAST(col2 as varchar)
FROM tb
WHERE col1=@col1
RETURN(STUFF(@re,1,1,''))
END
GO--调用函数
SELECT col1,col2=dbo.f_str(col1) FROM tb GROUP BY col1
--删除测试
DROP TABLE tb
DROP FUNCTION f_str
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
GO/*==============================================*/
--3.3.3 使用临时表实现字符串合并处理的示例
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3--合并处理
SELECT col1,col2=CAST(col2 as varchar(100))
INTO #t FROM tb
ORDER BY col1,col2
DECLARE @col1 varchar(10),@col2 varchar(100)
UPDATE #t SET
@col2=CASE WHEN @col1=col1 THEN @col2+','+col2 ELSE col2 END,
@col1=col1,
col2=@col2
SELECT * FROM #t
/*--更新处理后的临时表
col1 col2
---------- -------------
a 1
a 1,2
b 1
b 1,2
b 1,2,3
--*/
--得到最终结果
SELECT col1,col2=MAX(col2) FROM #t GROUP BY col1
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
--删除测试
DROP TABLE tb,#t
GO
/*==============================================*/--3.3.4.1 每组 <=2 条记录的合并
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'c',3--合并处理
SELECT col1,
col2=CAST(MIN(col2) as varchar)
+CASE
WHEN COUNT(*)=1 THEN ''
ELSE ','+CAST(MAX(col2) as varchar)
END
FROM tb
GROUP BY col1
DROP TABLE tb
/*--结果
col1 col2
---------- ----------
a 1,2
b 1,2
c 3
--*/--3.3.4.2 每组 <=3 条记录的合并
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3
UNION ALL SELECT 'c',3--合并处理
SELECT col1,
col2=CAST(MIN(col2) as varchar)
+CASE
WHEN COUNT(*)=3 THEN ','
+CAST((SELECT col2 FROM tb WHERE col1=a.col1 AND col2 NOT IN(MAX(a.col2),MIN(a.col2))) as varchar)
ELSE ''
END
+CASE
WHEN COUNT(*)>=2 THEN ','+CAST(MAX(col2) as varchar)
ELSE ''
END
FROM tb a
GROUP BY col1
DROP TABLE tb
/*--结果
col1 col2
---------- ------------
a 1,2
b 1,2,3
c 3
--*/
GO
发表于:2008-03-13 14:07:311楼 得分:0
SQL code--各种字符串分函数--3.3.1 使用游标法进行字符串合并处理的示例。
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3--合并处理
--定义结果集表变量
DECLARE @t TABLE(col1 varchar(10),col2 varchar(100))--定义游标并进行合并处理
DECLARE tb CURSOR LOCAL
FOR
SELECT col1,col2 FROM tb ORDER BY col1,col2
DECLARE @col1_old varchar(10),@col1 varchar(10),@col2 int,@s varchar(100)
OPEN tb
FETCH tb INTO @col1,@col2
SELECT @col1_old=@col1,@s=''
WHILE @@FETCH_STATUS=0
BEGIN
IF @col1=@col1_old
SELECT @s=@s+','+CAST(@col2 as varchar)
ELSE
BEGIN
INSERT @t VALUES(@col1_old,STUFF(@s,1,1,''))
SELECT @s=','+CAST(@col2 as varchar),@col1_old=@col1
END
FETCH tb INTO @col1,@col2
END
INSERT @t VALUES(@col1_old,STUFF(@s,1,1,''))
CLOSE tb
DEALLOCATE tb
--显示结果并删除测试数据
SELECT * FROM @t
DROP TABLE tb
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
GO
/*==============================================*/
--3.3.2 使用用户定义函数,配合SELECT处理完成字符串合并处理的示例
--处理的数据
CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3
GO--合并处理函数
CREATE FUNCTION dbo.f_str(@col1 varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+CAST(col2 as varchar)
FROM tb
WHERE col1=@col1
RETURN(STUFF(@re,1,1,''))
END
GO--调用函数
SELECT col1,col2=dbo.f_str(col1) FROM tb GROUP BY col1
--删除测试
DROP TABLE tb
DROP FUNCTION f_str
/*--结果
col1 col2
---------- -----------
a 1,2
b 1,2,3
--*/
GO
returs varchar
as
begin
declare @s varchar(1000)
if @c = 0
select @s = isnull(@s,'') + name +','
from ta
else
select @s = isnull(@s,'') + ltrim(id) +','
from ta
return @s
end
go
select dbo.f_str(type,1) as id ,dbo.f_str(type,0) as name
from ta
group by type
declare function dbo.getname(@id int,@m int)
returns varchar(100)
as
begin
declare @s varchar(800)
if @m = 0 select @s = isnull(@s+',','')+rtrim(id) from tn where type = @id order by id
else select @s = isnull(@s+',','')+rtrim(name) from tn where type = @id order by id
return @s
end
go
create table tn(id int,name varchar(10),type int)
insert tn select 1,'li',1
union all select 2,'liu',1
union all select 3,'wang',2
union all select 4,'ping',2
union all select 5,'wen',2
go
select dbo.getname(type,0) id,dbo.getname(type,1) name,type
from tn group by type
drop table tn
drop function dbo.getname
insert into ta select
1 ,'li', 1 union select
2 ,'liu', 1 union select
3 ,'wang', 2 union select
4 ,'ping', 2 union select
5 ,'wen', 2 gocreate function f_str(@type int,@c int)
returns varchar(20)
as
begin
declare @s varchar(1000)
if @c = 0
select @s = isnull(@s,'') + [name] +','
from ta
where type = @type
else
select @s = isnull(@s,'') + ltrim(id) +','
from ta
where type = @type
return @s
end
go
select dbo.f_str(type,1) as id ,dbo.f_str(type,0) as name,type
from ta
group by type
drop table ta
drop function f_str/*
id name type
-------------------- -------------------- -----------
1,2, li,liu, 1
3,4,5, wang,ping,wen, 2(所影响的行数为 2 行)*/
returns varchar(100)
as
begin
declare @s varchar(800)
if @m = 0 select @s = isnull(@s+',','')+rtrim(id) from tn where type = @id order by id
else select @s = isnull(@s+',','')+rtrim(name) from tn where type = @id order by id
return @s
end
go
create table tn(id int,name varchar(10),type int)
insert tn select 1,'li',1
union all select 2,'liu',1
union all select 3,'wang',2
union all select 4,'ping',2
union all select 5,'wen',2
go
select dbo.getname(type,0) id,dbo.getname(type,1) name,type
from tn group by type
drop table tn
drop function dbo.getname
create table tb(id int, name varchar(10) , type int)
insert into tb values(1, 'li' , 1 )
insert into tb values(2, 'liu' , 1 )
insert into tb values(3, 'wang', 2 )
insert into tb values(4, 'ping', 2 )
insert into tb values(5, 'wen' , 2 )
go--创建一个合并的函数,id
create function f_id(@type int)
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',' + cast(id as varchar) from tb where type = @type
set @str = right(@str , len(@str) - 1)
return(@str)
End
go
--创建一个合并的函数,name
create function f_name(@type int)
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',' + cast(name as varchar) from tb where type = @type
set @str = right(@str , len(@str) - 1)
return(@str)
End
go--调用自定义函数得到结果:
select distinct type ,dbo.f_id(type) as id , dbo.f_name(type) as name from tbdrop function dbo.f_id,dbo.f_name
drop table tb/*
type id name
------ ----- -------------
1 1,2 li,liu
2 3,4,5 wang,ping,wen(所影响的行数为 2 行)
*/
create table tb(id int, name varchar(10) , type int)
insert into tb values(1, 'li' , 1 )
insert into tb values(2, 'liu' , 1 )
insert into tb values(3, 'wang', 2 )
insert into tb values(4, 'ping', 2 )
insert into tb values(5, 'wen' , 2 )
go-- 查询处理
select t1.type , t1.id , t2.name from
(
SELECT * FROM(SELECT DISTINCT type FROM tb)A OUTER APPLY(
SELECT [id]= STUFF(REPLACE(REPLACE(
(
SELECT id FROM tb N
WHERE type = A.type
FOR XML AUTO
), '<N id="', ','), '"/>', ''), 1, 1, '')
)N
) t1,
(
SELECT * FROM(SELECT DISTINCT type FROM tb)A OUTER APPLY(
SELECT [name]= STUFF(REPLACE(REPLACE(
(
SELECT name FROM tb N
WHERE type = A.type
FOR XML AUTO
), '<N name="', ','), '"/>', ''), 1, 1, '')
)N
) t2
where t1.type = t2.typedrop table tb/*
type id name
------ ----- -------------
1 1,2 li,liu
2 3,4,5 wang,ping,wen(2 行受影响)
*/
create table tb(id int, name varchar(10) , type int)
insert into tb values(1, 'li' , 1 )
insert into tb values(2, 'liu' , 1 )
insert into tb values(3, 'wang', 2 )
insert into tb values(4, 'ping', 2 )
insert into tb values(5, 'wen' , 2 )
go-- 查询处理
select t1.type , t1.id , t2.name from
(
SELECT * FROM(SELECT DISTINCT type FROM tb)A OUTER APPLY(
SELECT [id]= STUFF(REPLACE(REPLACE(
(
SELECT id FROM tb N
WHERE type = A.type
FOR XML AUTO
), '<N id="', ','), '"/>', ''), 1, 1, '')
)N
) t1,
(
SELECT * FROM(SELECT DISTINCT type FROM tb)A OUTER APPLY(
SELECT [name]= STUFF(REPLACE(REPLACE(
(
SELECT name FROM tb N
WHERE type = A.type
FOR XML AUTO
), '<N name="', ','), '"/>', ''), 1, 1, '')
)N
) t2
where t1.type = t2.typedrop table tb
insert tn select 1,'li',1
union all select 2,'liu',1
union all select 3,'wang',2
union all select 4,'ping',2
union all select 5,'wen',2
go
select *,'1234567890' ids,'abcdefghijklmnopqrstuvwxyz' names into # from tn order by type,id
declare @i int,@ids varchar(100),@names varchar(100)
select @i = 0,@ids = '',@names=''
update # set ids = @ids,names = @names,
@ids = case when @i = type then @ids+','+rtrim(id) else rtrim(id) end,
@names = case when @i = type then @names+','+rtrim(name) else rtrim(name) end,
@i = type
select max(ids) id,max(names) name,type from # group by type
/*
id name type
---------- -------------------------- -----------
1,2 li,liu 1
3,4,5 wang,ping,wen 2
*/
drop table tn,#