有一张tba表
字段有
tba_id,f1,f2...
1 aaa bbb
2 aaa ccc另一张tbb表,是tba的从表
B表通过tba_id和A表tba_id关联,1对多的关系
tbb_id,tba_id,num,enable
1 1 10 T
2 1 11 F
3 1 12 F
4 1 13 T
5 2 12 T
6 2 13 T
7 2 14 F
8 2 15 F
9 2 16 F
现在想通过一次查询返回如下结果,把从表的结果合并进入2个字段
enable=T 的放在enable_num字段 enable=F 的放在disable_num字段
tba_id,f1, f2,enable_num,disable_num
1 aaa bbb 10,13 11,12
2 aaa CCC 12,13 14,15,16
字段有
tba_id,f1,f2...
1 aaa bbb
2 aaa ccc另一张tbb表,是tba的从表
B表通过tba_id和A表tba_id关联,1对多的关系
tbb_id,tba_id,num,enable
1 1 10 T
2 1 11 F
3 1 12 F
4 1 13 T
5 2 12 T
6 2 13 T
7 2 14 F
8 2 15 F
9 2 16 F
现在想通过一次查询返回如下结果,把从表的结果合并进入2个字段
enable=T 的放在enable_num字段 enable=F 的放在disable_num字段
tba_id,f1, f2,enable_num,disable_num
1 aaa bbb 10,13 11,12
2 aaa CCC 12,13 14,15,16
name num
aa 1
bb 2
cc 4
dd 4
ee 2
一条语句实现如下:
name
aa,bb,cc,dd,ee
DECLARE @STR VARCHAR(8000)
SELECT @STR=ISNULL(@STR+',','')+name FROM (SELECT DISTINCT NAME FROM A)AS T
SELECT @STR
问题描述:
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)
我现在有一字段值为:a,b,c
分隔符为逗号.
我现在想实现目地值为:
字段:
id name
1 a
2 b
3 c
在SQL中咋实现呢?
declare @str varchar(8000)
set @str = 'a1,b1,c2,d1,e3,f5'
set @str = 'select name='''+replace(@str,',',''''+' union all select ''')+''''
set @str='select id=identity(int,1,1),name into #temp from ('+@str+') a select * from #temp drop table #temp'
exec(@str)
--参考:
CREATE TABLE TB(ID VARCHAR(6), COLOR NVARCHAR(30))
INSERT TB
SELECT '173160', N'#特深蓝色,#特深蓝色' UNION ALL
SELECT '173160', N'#特深蓝色,#特深蓝色' UNION ALL
SELECT '911169', N'#宝蓝色,#宝蓝色,#花灰色,#花灰色' UNION ALL
SELECT '911169', N'#宝蓝色,#宝蓝色,#花灰色,#花灰色' UNION ALL
SELECT '911169', N'#宝蓝色,#宝蓝色,#花灰色,#花灰色' UNION ALL
SELECT '911169', N'#宝蓝色,#宝蓝色,#花灰色,#花灰色'
GO
CREATE FUNCTION F_getStr(@color nvarchar(30))
returns nvarchar(30)
as
begin
declare @str nvarchar(30),@temp nvarchar(30)
set @str=''
set @temp=''
while charindex(',', @color+',')>0
begin
set @temp=left(@color, charindex(',', @color+',')-1)
if charindex(','+@temp+',', ','+@str+',')=0
set @str=@str+','+@temp
set @color=stuff(@color, 1, charindex(',', @color+','), '')
end
return stuff(@str, 1, 1, '')
end
go
SELECT ID,dbo.F_getStr(COLOR) as COLOR FROM TB
DROP TABLE TB
DROP FUNCTION F_getStr
/*
ID COLOR
173160 #特深蓝色
173160 #特深蓝色
911169 #宝蓝色,#花灰色
911169 #宝蓝色,#花灰色
911169 #宝蓝色,#花灰色
911169 #宝蓝色,#花灰色
*/
(
select 1,'aaa','bbb' union all
select 2,'aaa','ccc'
)
,tbb (tbb_id,tba_id,num,enable) as
(
select 1,1,10,'T' union all
select 2,1,11,'F' union all
select 3,1,12,'F' union all
select 4,1,13,'T' union all
select 5,2,12,'T' union all
select 6,2,13,'T' union all
select 7,2,14,'F' union all
select 8,2,15,'F' union all
select 9,2,16,'F'
)
,a1 as
(
select a.tba_id,a.f1,a.f2
,case when b.enable='T' then b.num else 0 end enable_num
,case when b.enable='F' then b.num else 0 end disable_num
from tba a
inner join tbb b on a.tba_id=b.tba_id
)SELECT a.tba_id,a.f1,a.f2
,enable_num=stuff
(
(select case when enable_num=0 then ''else ','+RTRIM(enable_num) end as [text()]
from a1 b where a.tba_id=b.tba_id
for xml path('')
),1,1,'')
,disable_num=stuff
(
(select case when disable_num=0 then ''else ','+RTRIM(disable_num) end as [text()]
from a1 b where a.tba_id=b.tba_id
for xml path('')
),1,1,'')
FROM a1 a group by a.tba_id,a.f1,a.f2
INSERT INTO tba VALUES (1,'aaa','bbb')
INSERT INTO tba VALUES (2,'aaa','ccc')
GOCREATE TABLE tbb(tbb_id int,tba_id int,num int,[enable] VARCHAR(1))
INSERT INTO tbb VALUES (1,1,10,'T')
INSERT INTO tbb VALUES (2,1,11,'F')
INSERT INTO tbb VALUES (3,1,12,'F')
INSERT INTO tbb VALUES (4,1,13,'T')
INSERT INTO tbb VALUES (5,2,12,'T')
INSERT INTO tbb VALUES (6,2,13,'T')
INSERT INTO tbb VALUES (7,2,14,'F')
INSERT INTO tbb VALUES (8,2,15,'F')
INSERT INTO tbb VALUES (9,2,16,'F')
GO;with tb as(SELECT tbb.tba_id,tbb.num,tbb.[enable],tba.f1,tba.f2 FROM tbb,tba WHERE tbb.tba_id = tba.tba_id)
SELECT tba_id,f1,f2,
enable_num=stuff((SELECT ',' + cast(num AS VARCHAR) FROM tb WHERE tba_id = t.tba_id AND [enable]='T' FOR XML PATH('')),1,1,''),
disable_num=stuff((SELECT ',' + cast(num AS VARCHAR) FROM tb WHERE tba_id = t.tba_id AND [enable]='F' FOR XML PATH('')),1,1,'')
FROM tb t
GROUP BY tba_id,f1,f2
(
id INT,
f1 VARCHAR(3),
f2 VARCHAR(3)
)
INSERT INTO t1
SELECT 1,'aaa','bbb' UNION ALL
SELECT 2,'aaa','ccc'
CREATE TABLE t2
(
id INT,
tid INT,
num INT,
col VARCHAR(1)
)
INSERT INTO t2
SELECT 1,1,10,'T' UNION ALL
SELECT 2,1,11,'F' UNION ALL
SELECT 3,1,12,'F' UNION ALL
SELECT 4,1,13,'T' UNION ALL
SELECT 5,2,12,'T' UNION ALL
SELECT 6,2,13,'T' UNION ALL
SELECT 7,2,14,'F' UNION ALL
SELECT 8,2,15,'F' UNION ALL
SELECT 9,2,16,'F'
SELECT * FROM t1
SELECT * FROM t2;WITH aaa AS
(
SELECT tid,col,
stuff((SELECT ','+LTRIM(num)+',' FROM t2 AS b WHERE b.tid=a.tid AND b.col=a.col FOR XML PATH('')),1,1,'') AS val
FROM t2 AS a
GROUP BY tid,col
)
,bbb AS
(
SELECT tid,
MAX(CASE WHEN col='T' THEN val END) AS enable_num,
MAX(CASE WHEN col='F' THEN val END) AS disable_num
FROM aaa
GROUP BY tid
)
SELECT t1.id,
t1.f1,
t1.f2,
bbb.enable_num,
bbb.disable_num
FROM t1 INNER JOIN bbb ON t1.id=bbb.tidid f1 f2 enable_num disable_num
1 aaa bbb 10,,13, 11,,12,
2 aaa ccc 12,,13, 14,,15,,16,