求一更新SQL语句 - MS-SQL Server / 基础类

表结构


FItemNumber FEntryId
001
001
001
002
003
003


求一SQL语句，更新FEntryId如下
FItemNumber FEntryId
001 1  
001 2
001 3
002 1
003 1
003 2

除了游标循环，还有什么好方法。

---

顶。。。。

---

SQL code:
;with t as
(
select rn=row_number()over(partition by FItemNumber order by getdate()),*
from tb
)
update t set FentryID=rn

---

SQL code:
--------------------------------------------------------------------------
-- Author : htl258(Tony)
-- Date : 2010-04-18 10:05:10
-- Version:Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86)
-- Jul 9 2008 14:43:34
-- Copyright (c) 1988-2008 Microsoft Corporation
-- Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 2)
--------------------------------------------------------------------------
--> 生成测试数据表:tb

IF NOT OBJECT_ID('[tb]') IS NULL
DROP TABLE [tb]
GO
CREATE TABLE [tb]([FItemNumber] NVARCHAR(10),[FEntryId] INT)
INSERT [tb]
SELECT '001',1 UNION ALL
SELECT '001',NULL UNION ALL
SELECT '001',NULL