replace替换字符串的问题

[Derekwong]

replace(x,y,z)

1、搜索的的值 X：字符 a
2、要超找的值 Y：字符串 a,b,c,d
3、需要替换的 Z：空


需求： 字符串Y中以逗号分隔的字符完全和 搜索值X相等时，替换为空值。

希望达到的结果：

1、replace('ab','abc,abd','') = abc,abd
2、replace('ab','ab,abd','')  = abd
3、replace('ab','abc,ab','')  = abc

谢谢

[卖水果的net]

create table test(name varchar(30))
go
insert into test values('abc,abd'),('ab,abd'),('abc,ab')
go
-- 前后的逗号，你自己处理一下。
declare @f varchar(10) = 'ab'
select name, replace(',' + name + ',',  ',' + @f + ',', '') new_name from test
go
drop table test
go


(3 行受影响)
name                           new_name
------------------------------ ----------------------------------------------
abc,abd                        ,abc,abd,
ab,abd                         abd,
abc,ab                         ,abc

(3 行受影响)

[吉普赛的歌]

USE tempdb
GO
IF OBJECT_ID('t') IS NOT NULL DROP TABLE t
GO
CREATE TABLE t(
	v NVARCHAR(20)	
)
GO
INSERT INTO t VALUES ('abc,abd')
INSERT INTO t VALUES ('ab,abd')
INSERT INTO t VALUES ('abc,ab')

DECLARE @search NVARCHAR(20)
SET @search='ab'

SELECT 
v
,CASE WHEN left(t2.vResult,1)=',' THEN SUBSTRING(t2.vResult,2,LEN(t2.vResult))
	  WHEN RIGHT(t2.vResult,1)=',' THEN SUBSTRING(t2.vResult,1,LEN(t2.vResult)-1)
	  ELSE t2.vResult END AS vResult 
FROM (
	SELECT * 
	,CASE WHEN ','+v+',' LIKE '%,'+@search+',%' THEN REPLACE(','+v+',',','+@search+',','') ELSE v END AS vResult 
	FROM t
) AS t2
/*
v                    vResult
-------------------- -------------
abc,abd              abc,abd
ab,abd               abd
abc,ab               abc
*/

[Derekwong]

引用 2 楼 吉普赛的歌 的回复:

USE tempdb
GO
IF OBJECT_ID('t') IS NOT NULL DROP TABLE t
GO
CREATE TABLE t(
	v NVARCHAR(20)	
)
GO
INSERT INTO t VALUES ('abc,abd')
INSERT INTO t VALUES ('ab,abd')
INSERT INTO t VALUES ('abc,ab')

DECLARE @search NVARCHAR(20)
SET @search='ab'

SELECT 
v
,CASE WHEN left(t2.vResult,1)=',' THEN SUBSTRING(t2.vResult,2,LEN(t2.vResult))
	  WHEN RIGHT(t2.vResult,1)=',' THEN SUBSTRING(t2.vResult,1,LEN(t2.vResult)-1)
	  ELSE t2.vResult END AS vResult 
FROM (
	SELECT * 
	,CASE WHEN ','+v+',' LIKE '%,'+@search+',%' THEN REPLACE(','+v+',',','+@search+',','') ELSE v END AS vResult 
	FROM t
) AS t2
/*
v                    vResult
-------------------- -------------
abc,abd              abc,abd
ab,abd               abd
abc,ab               abc
*/

版主，您好，代码测试正常，如果问题中，V字符串对应查找的字符有2个值得，@search1和@search2，应该怎么修改。

[Derekwong]

引用 2 楼 吉普赛的歌 的回复:

USE tempdb
GO
IF OBJECT_ID('t') IS NOT NULL DROP TABLE t
GO
CREATE TABLE t(
	v NVARCHAR(20)	
)
GO
INSERT INTO t VALUES ('abc,abd')
INSERT INTO t VALUES ('ab,abd')
INSERT INTO t VALUES ('abc,ab')

DECLARE @search NVARCHAR(20)
SET @search='ab'

SELECT 
v
,CASE WHEN left(t2.vResult,1)=',' THEN SUBSTRING(t2.vResult,2,LEN(t2.vResult))
	  WHEN RIGHT(t2.vResult,1)=',' THEN SUBSTRING(t2.vResult,1,LEN(t2.vResult)-1)
	  ELSE t2.vResult END AS vResult 
FROM (
	SELECT * 
	,CASE WHEN ','+v+',' LIKE '%,'+@search+',%' THEN REPLACE(','+v+',',','+@search+',','') ELSE v END AS vResult 
	FROM t
) AS t2
/*
v                    vResult
-------------------- -------------
abc,abd              abc,abd
ab,abd               abd
abc,ab               abc
*/

USE tempdb
GO
IF OBJECT_ID('t') IS NOT NULL DROP TABLE t
GO
CREATE TABLE t(
    v NVARCHAR(20)   
)
GO
INSERT INTO t VALUES ('abc,abd')
INSERT INTO t VALUES ('ab,abd')
INSERT INTO t VALUES ('abc,ab')
 
DECLARE @search NVARCHAR(20)
SET @search1='ab'

版主，如果对应查找的变量有2个，应该怎么修改达到结果。 @search1='ab' @search2='abc' v vResult -------------------- ------------- abc,abd abd ab,abd abd abc,ab */

[吉普赛的歌]

USE tempdb
GO
IF OBJECT_ID('t') IS NOT NULL DROP TABLE t
GO
CREATE TABLE t(
	v NVARCHAR(20)	
)
GO
INSERT INTO t VALUES ('abc,abd')
INSERT INTO t VALUES ('ab,abd')
INSERT INTO t VALUES ('abc,ab')
------------ 以上为测试表及测试数据

------------ 增加一个表值分割函数
IF OBJECT_ID('[dbo].[Fun_String2ToStringArray]') IS NOT NULL 
	DROP FUNCTION [dbo].[Fun_String2ToStringArray]
GO
CREATE FUNCTION [dbo].[Fun_String2ToStringArray](@str NVARCHAR(MAX), @split NVARCHAR(10))
RETURNS @table TABLE ([item] NVARCHAR(max))
AS
BEGIN
    IF LEN(@split) = 0
      BEGIN
        SET @split = N','
      END
 
    DECLARE @xml XML;
    SET @xml = CONVERT(XML, '<x><![CDATA[' + replace(CONVERT(VARCHAR(MAX), @str), @split, ']]></x><x><![CDATA[') + ']]></x>')
 
    INSERT INTO @table
      SELECT item
      FROM   (SELECT c.value('text()[1]', 'nvarchar(4000)') [item]
              FROM   @xml.nodes('/x') t(c)) t
      WHERE  item IS NOT NULL
 
    RETURN
END
GO

------------------ 查询
DECLARE @search1 NVARCHAR(20),@search2 NVARCHAR(20)
SET @search1='ab'
SET @search2='abc'

SELECT 
v
,ISNULL((SELECT item FROM [dbo].[Fun_String2ToStringArray](t.v,',') WHERE item NOT IN (@search1,@search2) ),'') AS vResult
FROM t 

/*
v                    vResult
-------------------- -------------
abc,abd              abd
ab,abd               abd
abc,ab               
*/