一段TSQL脚本，自用
USE [WMDRM]
GO
/****** 对象: Index [unique_keyvalue] 脚本日期: 11/20/2012 11:26:42 ******/
IF EXISTS (SELECT * FROM sys.indexes WHERE object_id = OBJECT_ID(N'[dbo].[Key]') AND name = N'unique_keyvalue')
ALTER TABLE [dbo].[Key] DROP CONSTRAINT [unique_keyvalue]
