用sql语句如何给字段添加和去掉identity属性

--在SQL SERVER的Enterprise Manage中,先建一个表


--然后右击,选择Design Table,添加了Identity属性后,用Save Change Script按钮


--看看系统是怎么做的,去掉Identity同理.


--假如建了表a，id有identity属性


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


--1.创建表


if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[a]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)


drop table [dbo].[a]


GO




CREATE TABLE [dbo].[a] (


[id] [int] NOT NULL ,


[title] [char] (10) COLLATE Chinese_PRC_CI_AS NULL


) ON [PRIMARY]


GO


--2.加identity属性


BEGIN TRANSACTION


SET QUOTED_IDENTIFIER ON


SET TRANSACTION ISOLATION LEVEL SERIALIZABLE


SET ARITHABORT ON


SET NUMERIC_ROUNDABORT OFF


SET CONCAT_NULL_YIELDS_NULL ON


SET ANSI_NULLS ON


SET ANSI_PADDING ON


SET ANSI_WARNINGS ON


COMMIT


BEGIN TRANSACTION


CREATE TABLE dbo.Tmp_a


(


id int NOT NULL IDENTITY (1, 1),


title char(10) NULL


) ON [PRIMARY]


GO


SET IDENTITY_INSERT dbo.Tmp_a ON


GO


IF EXISTS(SELECT * FROM dbo.a)


EXEC('INSERT INTO dbo.Tmp_a (id, title)


SELECT id, title FROM dbo.a TABLOCKX')


GO


SET IDENTITY_INSERT dbo.Tmp_a OFF


GO


DROP TABLE dbo.a


GO


EXECUTE sp_rename N'dbo.Tmp_a', N'a', 'OBJECT'


GO


ALTER TABLE dbo.a ADD CONSTRAINT


PK_a PRIMARY KEY CLUSTERED


(


id


) ON [PRIMARY]




GO


COMMIT


--3.去掉identity属性


BEGIN TRANSACTION


SET QUOTED_IDENTIFIER ON


SET TRANSACTION ISOLATION LEVEL SERIALIZABLE


SET ARITHABORT ON


SET NUMERIC_ROUNDABORT OFF


SET CONCAT_NULL_YIELDS_NULL ON


SET ANSI_NULLS ON


SET ANSI_PADDING ON


SET ANSI_WARNINGS ON


COMMIT


BEGIN TRANSACTION


CREATE TABLE dbo.Tmp_a


(


id int NOT NULL,


title char(10) NULL


) ON [PRIMARY]


GO


IF EXISTS(SELECT * FROM dbo.a)


EXEC('INSERT INTO dbo.Tmp_a (id, title)


SELECT id, title FROM dbo.a TABLOCKX')


GO


DROP TABLE dbo.a


GO


EXECUTE sp_rename N'dbo.Tmp_a', N'a', 'OBJECT'


GO


ALTER TABLE dbo.a ADD CONSTRAINT


PK_a PRIMARY KEY CLUSTERED


(


id


) ON [PRIMARY]




GO


COMMIT