create table testing1

(

cID int identity(1,1) not null,

cname varchar(50)

)

select *From testing1

insert into testing1 values ('sunil2')

insert into testing1 values ('sunil6')

insert into testing1 values ('sunil7')

insert into testing1 values ('sunil8')

insert into testing1 values ('sunil9')

insert into testing1 values ('sunil10')

insert into testing1 values ('sunil11')

Result

cID cname

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

1 sunil

2 sunil6

3 sunil7

4 sunil8

5 sunil9

6 sunil10

7 sunil11

than delete record 2,4,6

Than Result

cID cname

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

1 sunil

3 sunil7

5 sunil9

7 sunil11

than Drop column Cid and create again

ALTER TABLE testing1 DROP COLUMN Cid

GO

ALTER TABLE testing1 ADD Cid INT IDENTITY (1,3) NOT NULL

GO

select *from testing1

result

cname Cid

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

sunil 1

sunil7 4

sunil9 7

sunil11 10

(4 row(s) affected)