create table t1(编号 int)
insert into t1 select 1 union all select 5 union all select 19 union all select 22
go
alter table t1 add id int identity(1,1)
select * from t1
/*
编号          id
----------- -----------
1           1
5           2
19          3
22          4

(4 行受影响)

*/
go
drop table t1

------解决方案--------------------
SQL code

create table #t(n varchar(10));
go

insert into #t select 'a' union all
select 'b' union all
select 'c' union all 
select 'd';

--select * from #t;

alter table #t add id int primary key identity(1,1);

select * from #t;

------解决方案--------------------
SQL code
alter table t1 add id identity(int,1,1) 
update t1 set id=编号

------解决方案--------------------
SQL code
alter table ta add id int not null identity(1,1)

------解决方案--------------------
SQL code
alter table t1 add id identity(1,1) 
update t1 set id=编号

------解决方案--------------------
如果原表中存储的物理顺序并非按编号排列的,则:
SQL code
create table t1(编号 int)
insert into t1 select 11 union all select 5 union all select 19 union all select 22 union all select 7
go
select * into temp_t1 from t1 order by 编号
alter table temp_t1 add id int identity(1,1)
drop table t1
go
exec sp_rename 'temp_t1','t1'
go
select * from t1
/*
编号          id
----------- -----------
5           1
7           2
11          3
19          4
22          5

(5 行受影响)
*/
go
drop table t1

------解决方案--------------------
SQL code
alter table t1 add id int identity(1,1) 
update t1 set id=编号