使用约束时，MS SQL Server 2008脚本生成会创建无效脚本

在MS SQL Server 2008（10.50.2811.0）开发人员版（64位）上，在Windows 2008 Server 2008 R2 Standard下运行SQL Server Management Studio会创建多次丢弃相同约束的脚本。使用约束时，MS SQL Server 2008脚本生成会创建无效脚本

一个简单的例子包括两个表tParent和tChild，其中tChild的ParentID引用tParent的ID。该脚本（数据库上下文菜单=>任务=>生成脚本...）生成（用于删除并创建）看起来是这样的：

USE [TestDb] 
GO 
/****** Object: ForeignKey [FK_tChild_tParent] Script Date: 08/08/2012 08:11:51 ******/ 
ALTER TABLE [dbo].[tChild] DROP CONSTRAINT [FK_tChild_tParent] 
GO 
/****** Object: Table [dbo].[tChild] Script Date: 08/08/2012 08:11:51 ******/ 
ALTER TABLE [dbo].[tChild] DROP CONSTRAINT [FK_tChild_tParent] 
GO 
DROP TABLE [dbo].[tChild] 
GO 
/****** Object: Table [dbo].[tParent] Script Date: 08/08/2012 08:11:52 ******/ 
DROP TABLE [dbo].[tParent] 
GO 
/****** Object: Table [dbo].[tParent] Script Date: 08/08/2012 08:11:52 ******/ 
SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
CREATE TABLE [dbo].[tParent](
[ID] [int] IDENTITY(1,1) NOT NULL, 
[Name] [varchar](50) NOT NULL, 
[Value] [int] NOT NULL, 
CONSTRAINT [PK_tParent] PRIMARY KEY CLUSTERED 
(
[ID] ASC 
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] 
) ON [PRIMARY] 
GO 
/****** Object: Table [dbo].[tChild] Script Date: 08/08/2012 08:11:51 ******/ 
SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
CREATE TABLE [dbo].[tChild](
[ID] [int] IDENTITY(1,1) NOT NULL, 
[ParentID] [int] NOT NULL, 
[Name] [varchar](50) NOT NULL, 
[Value] [int] NOT NULL, 
CONSTRAINT [PK_tChild] PRIMARY KEY CLUSTERED 
(
[ID] ASC 
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] 
) ON [PRIMARY] 
GO 
/****** Object: ForeignKey [FK_tChild_tParent] Script Date: 08/08/2012 08:11:51 ******/ 
ALTER TABLE [dbo].[tChild] WITH CHECK ADD CONSTRAINT [FK_tChild_tParent] FOREIGN KEY([ParentID]) 
REFERENCES [dbo].[tParent] ([ID]) 
GO 
ALTER TABLE [dbo].[tChild] CHECK CONSTRAINT [FK_tChild_tParent] 
GO

为什么有两个相同的线，这两个尝试删除该FK_tChild_tParent约束？为什么两条线的评论都不一样？

来源

2012-08-08 Gorgsenegger