在不生成列的顺序号前提下对无序列出现的首行进行标注

在不生成列的顺序号前提下对无序列出现的首行进行标注

刚才在微软中文论坛逛的时候看到一个题目,其实方法很多,能不能在不生成列的顺序号(如排名函数,生成唯一编号。。。)前提下对无序列出现的首行进行标注呢,

数据准备:

TAmyname varchar(10),nameId varchar(10)

MyName nameId

aaa

aaa

aaa

aaa

bbb

bb

ccc

ccc

bb

要求结果如下:

MyName NameID

aaa new

aaa old

aaa old

aaa old

bbb new

bb new

ccc new

ccc old

bb old

------------------------------------

-- AUTHOR: FLYSTONE

-- VERSION:V1.001

-- DATE:2009-11-05 22:50

------------------------------------

-- TEST DATA: TA

IF OBJECT_ID('TA') IS NOT NULL

DROP TABLE TA

GO

CREATE TABLE TA(MYNAME NVARCHAR(10))

GO

INSERT INTO TA

SELECT 'AAA' UNION ALL

SELECT 'AAA' UNION ALL

SELECT 'AAA' UNION ALL

SELECT 'AAA' UNION ALL

SELECT 'BBB' UNION ALL

SELECT 'BB' UNION ALL

SELECT 'CCC' UNION ALL

SELECT 'CCC' UNION ALL

SELECT 'BB'

GO

--START

ALTER TABLE TA ADD NAMEID VARCHAR(10)

GO

DECLARE @S VARCHAR(10),@S1 VARCHAR(8000)

SET @S1 = '' --这一句不能少,否则狗儿屁

UPDATE A

SET NAMEID = CASE WHEN CHARINDEX( ','+MYNAME +',',','+@S1+',') > 0 THEN 'OLD'

ELSE 'NEW'

END ,

@S1 = CASE WHEN CHARINDEX( ','+CAST(@S+'' AS VARCHAR(10)) +',',','+@S1+',') > 0 THEN @S1

ELSE @S1+','+ISNULL(CAST(@S+'' AS VARCHAR(10)),'')

END ,

@S = MYNAME

FROM TA A

SELECT * FROM TA

--RESULT:

/*

MYNAME NAMEID

---------- ----------

AAA NEW

AAA OLD

AAA OLD

AAA OLD

BBB NEW

BB NEW

CCC NEW

CCC OLD

BB OLD

*/

--END

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