原内容:
字段1 字段2 字段3 字段4
1111 222 A 1
1111 333 A 1
2222 999 B 2
3333 111 B 2写个什么SQL语句能实现如下的数据结构
新内容:新字段1 字段3 字段4
1111-222,333 A 1
2222-999,3333-111 B 2
谢谢了。
字段1 字段2 字段3 字段4
1111 222 A 1
1111 333 A 1
2222 999 B 2
3333 111 B 2写个什么SQL语句能实现如下的数据结构
新内容:新字段1 字段3 字段4
1111-222,333 A 1
2222-999,3333-111 B 2
谢谢了。
无论是在sql 2000,还是在 sql 2005 中,都没有提供字符串的聚合函数,
所以,当我们在处理下列要求时,会比较麻烦:
有表tb, 如下:
id value
----- ------
1 aa
1 bb
2 aaa
2 bbb
2 ccc
需要得到结果:
id values
------ -----------
1 aa,bb
2 aaa,bbb,ccc
即, group by id, 求 value 的和(字符串相加)1. 旧的解决方法-- 1. 创建处理函数
CREATE FUNCTION dbo.f_str(@id int)
RETURNS varchar(8000)
AS
BEGIN
DECLARE @r varchar(8000)
SET @r = ''
SELECT @r = @r + ',' + value
FROM tb
WHERE id=@id
RETURN STUFF(@r, 1, 1, '')
END
GO
-- 调用函数SELECt id, values=dbo.f_str(id)
FROM tb
GROUP BY id-- 2. 新的解决方法
-- 示例数据
DECLARE @t TABLE(id int, value varchar(10))
INSERT @t SELECT 1, 'aa'
UNION ALL SELECT 1, 'bb'
UNION ALL SELECT 2, 'aaa'
UNION ALL SELECT 2, 'bbb'
UNION ALL SELECT 2, 'ccc'-- 查询处理
SELECT *
FROM(
SELECT DISTINCT
id
FROM @t
)A
OUTER APPLY(
SELECT
[values]= STUFF(REPLACE(REPLACE(
(
SELECT value FROM @t N
WHERE id = A.id
FOR XML AUTO
), '<N value="', ','), '"/>', ''), 1, 1, '')
)N/*--结果
id values
----------- ----------------
1 aa,bb
2 aaa,bbb,ccc
(2 行受影响)
--*/--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/*==============================================*/
--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
if not object_id('A') is null
drop table A
Go
Create table A([id] int,[cname] nvarchar(2))
Insert A
select 1,N'张三' union all
select 2,N'李四' union all
select 3,N'王五' union all
select 4,N'蔡六'
Go
--> -->
if not object_id('B') is null
drop table B
Go
Create table B([id] int,[cname] nvarchar(5))
Insert B
select 1,N'1,2,3' union all
select 2,N'3,4'
Go
create function F_str(@cname nvarchar(100))
returns nvarchar(100)
as
begin
select @cname=replace(@cname,ID,[cname]) from A where patindex('%,'+rtrim(ID)+',%',','+@cname+',')>0
return @cname
end
go
select [id],dbo.F_str([cname])[cname] from Bid cname
----------- ----------------------------------------------------------------------------------------------------
1 张三,李四,王五
2 王五,蔡六(2 個資料列受到影響)
1111 222 A 1
1111 333 A 1
2222 999 B 2
3333 111 B 3 如果是上面的数据,结果是不是这样?新字段1 字段3 字段4
1111-222,333 A 1
2222-999 B 2
3333-111 B 3
无论是在sql 2000,还是在 sql 2005 中,都没有提供字符串的聚合函数,
所以,当我们在处理下列要求时,会比较麻烦:
有表tb, 如下:
id value
----- ------
1 aa
1 bb
2 aaa
2 bbb
2 ccc
需要得到结果:
id values
------ -----------
1 aa,bb
2 aaa,bbb,ccc
即, group by id, 求 value 的和(字符串相加)1. 旧的解决方法-- 1. 创建处理函数
CREATE FUNCTION dbo.f_str(@id int)
RETURNS varchar(8000)
AS
BEGIN
DECLARE @r varchar(8000)
SET @r = ''
SELECT @r = @r + ',' + value
FROM tb
WHERE id=@id
RETURN STUFF(@r, 1, 1, '')
END
GO
-- 调用函数SELECt id, values=dbo.f_str(id)
FROM tb
GROUP BY id-- 2. 新的解决方法
-- 示例数据
DECLARE @t TABLE(id int, value varchar(10))
INSERT @t SELECT 1, 'aa'
UNION ALL SELECT 1, 'bb'
UNION ALL SELECT 2, 'aaa'
UNION ALL SELECT 2, 'bbb'
UNION ALL SELECT 2, 'ccc'-- 查询处理
SELECT *
FROM(
SELECT DISTINCT
id
FROM @t
)A
OUTER APPLY(
SELECT
[values]= STUFF(REPLACE(REPLACE(
(
SELECT value FROM @t N
WHERE id = A.id
FOR XML AUTO
), '<N value="', ','), '"/>', ''), 1, 1, '')
)N/*--结果
id values
----------- ----------------
1 aa,bb
2 aaa,bbb,ccc
(2 行受影响)
--*/
insert into tab select
'1111','222','A',1 union all select
'1111','333','A',1 union all select
'2222','999','B',2 union all select
'3333','111','B',2
CREATE FUNCTION dbo.f_str(@id varchar(10))
RETURNS varchar(8000)
AS
BEGIN
DECLARE @r varchar(8000)
SET @r = ''
SELECT @r = @r + ',' + 字段1+'-'+字段2
FROM tab
WHERE 字段3=@id
RETURN STUFF(@r, 1, 1, '')
END
GOselect dbo.f_str(字段3),字段3,字段4 from tab group by 字段3,字段4/*
字段3 字段4
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ---------- -----------
1111-222,1111-333 A 1
2222-999,3333-111 B 2(所影响的行数为 2 行)*/
drop function dbo.f_strdrop table tab
INSERT TB
SELECT 1111, 222, 'A', 1 UNION ALL
SELECT 1111, 333, 'A', 1 UNION ALL
SELECT 2222, 999, 'B', 2 UNION ALL
SELECT 3333, 111, 'B', 2
GO
CREATE FUNCTION F_COMBINESTR(@COL1 VARCHAR(1), @COL2 INT)
RETURNS VARCHAR(100)
AS
BEGIN
DECLARE @SQL VARCHAR(100)
SET @SQL=''
SELECT @SQL=@SQL+',' + CASE WHEN CHARINDEX(rtrim([字段1]),@SQL)=0 THEN rtrim([字段1])+'-' ELSE '' END+CASE WHEN CHARINDEX(rtrim([字段2]),@SQL)=0 THEN rtrim([字段2]) ELSE '' END FROM TB WHERE [字段3]=@COL1 AND [字段4]=@COL2
RETURN STUFF(@SQL, 1, 1, '')
END
GOSELECT 新字段1=dbo.F_COMBINESTR([字段3],[字段4]),[字段3],[字段4]
FROM TB
GROUP BY [字段3],[字段4]DROP FUNCTION F_COMBINESTR
DROP TABLE TB
/*
1111-222,333 A 1
2222-999,3333-111 B 2
*/
--> 测试数据: [ta]
if object_id('[ta]') is not null drop table [ta]
create table [ta] (字段1 int,字段2 int,字段3 varchar(1),字段4 int)
insert into [ta]
select 1111,222,'A',1 union all
select 1111,333,'A',1 union all
select 2222,999,'B',2 union all
select 3333,111,'B',2--合并函数:
create FUNCTION dbo.gets(@字段3 varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @sql varchar(100)
SELECT @sql = isnull(@sql+',','')+
case when charindex(ltrim(字段1),isnull(@sql,''))>0 then ltrim(字段2) else ltrim(字段1)+'-' + ltrim(字段2) end FROM ta WHERE 字段3=@字段3
RETURN @sql
END
GO
select distinct 新字段1=dbo.gets(字段3),字段3,字段4 from ta--结果:
新字段1 字段3 字段4
---------------------------------------------------------------------------------------------------- ---- -----------
1111-222,333 A 1
2222-999,3333-111 B 2
insert into tab select
'1111','222','A',1 union all select
'1111','333','A',1 union all select
'2222','999','B',2 union all select
'3333','111','B',3
CREATE FUNCTION dbo.f_str(@id int)
RETURNS varchar(8000)
AS
BEGIN
DECLARE @r varchar(8000)
SET @r = ''
SELECT @r = @r + ',' + 字段1+'-'+字段2
FROM tab
WHERE 字段4=@id
RETURN STUFF(@r, 1, 1, '')
END
GOselect dbo.f_str(字段4) 新字段,字段3,字段4 from tab group by 字段3,字段4/*
新字段 字段3 字段4
----------------------------- ---------- -----------
1111-222,1111-333 A 1
2222-999 B 2
3333-111 B 3(所影响的行数为 3 行)
*/
drop function dbo.f_strdrop table tab
if object_id('[tb]') is not null drop table [tb]
go
create table [tb](f1 int,f2 int,f3 varchar(1),f4 int)
insert [tb]
select 1111,222,'A',1 union all
select 1111,333,'A',1 union all
select 2222,999,'B',2 union all
select 3333,111,'B',2
go
--select * from [tb]with szx as
(
select f1,f2=stuff((select ','+rtrim(f2) from tb where f1=t.f1 and f3=t.f3 and f4=t.f4 for xml path('')),1,1,''),f3,f4
from tb t
group by f1,f3,f4
)
select f12=stuff((select ','+rtrim(f1)+'-'+f2 from szx where f3=t.f3 and f4=t.f4 for xml path('')),1,1,''),f3,f4
from szx t
group by f3,f4
/*
f12 f3 f4
---------------------------
1111-222,333 A 1
2222-999,3333-111 B 2
*/
go
insert tb select '1111' , '222' , 'A' , 1
insert tb select '1111' , '333' , 'A' , 1
insert tb select '2222' , '999' , 'B' , 2
insert tb select '3333' , '111' , 'B' , 2
go
create FUNCTION dbo.f_str(@col3 varchar(10))
RETURNS varchar(8000)
AS
BEGIN
--用游标
declare @str varchar(8000),@col1 varchar(10),@col2 varchar(10)
set @str=''
--定义游标
declare DZCursor CURSOR for SELECT col1,col2 FROM tb where col3=@col3
--打开游标
open DZCursor
--从游标取记录
fetch next from DZCursor into @col1,@col2
--当有记录
while @@fetch_status=0
begin
if charindex(@col1+'-',@str)=0 and charindex('-'+@col1,@str)=0
set @str=@str+@col1+'-'
if charindex(@col2+'-',@str)=0 and charindex('-'+@col2,@str)=0
set @str=@str+@col2+','
--取下一条记录
fetch next from DZCursor into @col1,@col2
end
--关闭游标
close DZCursor
--删除游标引用
deallocate DZCursor
return left(@str,len(@str)-1)
ENDselect distinct newcol=dbo.f_str(col3),col3,col4 from tb /*
newcol col3 col4
--------------------------------
1111-222,333 A 1
2222-999,3333-111 B 2*/
drop table tb
drop function f_str
11111 222 A 1
1111 333 A 1
2222 999 B 2
3333 111 B 2
create table tb(col1 varchar(10),col2 varchar(10),col3 varchar(10),col4 varchar(10))
go
insert tb select '11111' , '222' , 'A' , 1
insert tb select '1111' , '333' , 'A' , 1
insert tb select '2222' , '999' , 'B' , 2
insert tb select '3333' , '111' , 'B' , 2
go
create FUNCTION dbo.f_str(@col3 varchar(10))
RETURNS varchar(8000)
AS
BEGIN
declare @str varchar(8000)
set @str=''
select @str=@str+case when charindex(','+col1+'-',','+@str+'-')=0 and charindex('-'+col1+',','-'+@str+',')=0 then col1+'-' else '' end
+case when charindex(','+col1+'-',','+@str+'-')=0 and charindex('-'+col1+',','-'+@str+',')=0 then col2+',' else '' end
from tb where col3=@col3
return left(@str,len(@str)-1)
END
go
select distinct newcol=dbo.f_str(col3),col3,col4 from tb /*
newcol col3 col4
--------------------------------
11111-222,1111-333 A 1
2222-999,3333-111 B 2
*/
drop table tb
drop function f_str
create table tb(col1 varchar(10),col2 varchar(10),col3 varchar(10),col4 varchar(10))
go
insert tb select '11111' , '222' , 'A' , 1
insert tb select '1111' , '333' , 'A' , 1
insert tb select '2222' , '999' , 'B' , 2
insert tb select '3333' , '111' , 'B' , 2
go
create FUNCTION dbo.f_str(@col3 varchar(10))
RETURNS varchar(8000)
AS
BEGIN
declare @str varchar(8000)
set @str=''
select @str=@str+case when charindex(','+col1+'-',','+@str+'-')=0 then col1+'-' else '' end
+case when charindex('-'+col2+',','-'+@str+',')=0 then col2+',' else '' end
from tb where col3=@col3
return left(@str,len(@str)-1)
END
go
select distinct newcol=dbo.f_str(col3),col3,col4 from tb /*
newcol col3 col4
--------------------------------
11111-222,1111-333 A 1
2222-999,3333-111 B 2
*/
drop table tb
drop function f_str
insert into @T
select '1111', '222', 'A', '1' union all
select '1111', '333', 'A', '1' union all
select '2222', '999', 'B', '2' union all
select '3333', '111', 'B', '2' ;with cte as
(
select
col1,
col2 = stuff((select ','+col2 from @T where col1 = a.col1 and col3 = a.col3 and col4 = a.col4 for xml path('')),1,1,''),
col3,
col4
from @T a
group by col1,col3,col4
)
select col1 = stuff((select ','+col1+'-'+col2 from cte where a.col3 = col3 and a.col4 = col4 for xml path('')),1,1,''),
col4,
col3
from cte a
group by col3,col4