将sql Server 的table的列 ，由非自增长改为自增长

转载：http://www.thinksaas.cn/topics/0/423/423869.html

Demo

/**************** 准备环境********************/

--判断是否存在test表
if object_id(N‘test‘,N‘U‘) is not null
drop table test

--创建test表
create table test
(
id int not null,
name varchar(20) not null
)

--插入临时数据
insert into test values (1,‘成龙‘)
insert into test values (3,‘章子怡‘)
insert into test values (4,‘刘若英‘)
insert into test values (8,‘王菲‘)

select * from test

/**************** 实现更改自动增长列********************/

begin transaction

create table test_tmp
(
id int not null identity(1,1),
name varchar(20) not null
)
go

set identity_insert test_tmp on
go

if exists(select * from test)
exec(‘ insert into test_tmp(id, name ) select id, name from test with(holdlock tablockx)‘)
go

set identity_insert test_tmp off
go

drop table test
go

exec sp_rename N‘test_tmp‘ ,N‘test‘ , ‘OBJECT‘
go

commit

GO

/****************验证结果*****************/
insert into test values (‘张曼‘)
select * from test

实例：

/**************** 实现更改自动增长列********************/

begin transaction

create table test_tmp
(
UserGradeID int not null identity(1,1),
UserGrade nvarchar(8) not null,
[Status] int not null,
Remark nvarchar(128) ,
adduser nvarchar(32) ,
upduser nvarchar(32) ,
addtime datetime2(7) ,
updtime datetime2(7)
)
go

set identity_insert test_tmp on
go

if exists(select * from m_usergrade)

exec(‘ insert into test_tmp(UserGradeID,UserGrade,[Status],Remark,adduser,upduser,addtime,updtime )
select UserGradeID,UserGrade,[Status],Remark,adduser,upduser,addtime,updtime from m_usergrade with(holdlock tablockx)‘)
go

set identity_insert test_tmp off
go

drop table m_usergrade
go

exec sp_rename N‘test_tmp‘ ,N‘m_usergrade‘ , ‘OBJECT‘
go

commit

GO