sequence number Add in sql server Query

Query

select au_id,authors_name from Mytable1 order by au_id

Results

12	Sidney Sheldon
76	David Taylor
100	Mathew Arnold
127	Agatha Christy
140	Keith Davis

au_id is unique in this table, so it is easy to use a co-related sub-query to generate sequential numbers.

Query

SELECT (SELECT count(au_id) FROM Mytable1 AS x WHERE x.au_id<= y.au_id) AS
Sequence, au_id,authors_name
FROM Mytable1 AS y order by au_id

Results

1	12	Sidney Sheldon
2	76	David Taylor
3	100	Mathew Arnold
4	127	Agatha Christy
5	140	Keith Davis

Note: “au_id” is a unique column.

Example 2:

Generate unique sequence numbers for a table that has no unique column.

Let us consider the table shown below. For tables with no unique columns, it is easy to use the identity function to generate unique sequence numbers.

Use tempdb
go
Create table Mytable2 (au_id int, authors_name varchar(100))
Go
insert into MyTable2 select 100,'Mathew Arnold'
insert into MyTable2 select 140,'Keith Davis'
insert into MyTable2 select 76,'David Taylor'
insert into MyTable2 select 127,'Agatha Christy'
insert into MyTable2 select 12,'Sidney Sheldon'
insert into MyTable2 select 12,'Mcarthur'
insert into MyTable2 select 76,'Alan Smiles'
insert into MyTable2 select 100,'Kreisler'
go

Query

select * from mytable2 order by au_id

Results

12	Sidney Sheldon
12	Mcarthur
76	Alan Smiles
76	David Taylor
100	Mathew Arnold
100	Kreisler
127	Agatha Christy
140	Keith Davis

Query

select identity(int,1,1) as Sequence, au_id,authors_name into #x from Mytable2 order by au_id
go
select * from #x
go
drop table #x
go

Results

1	12	Sidney Sheldon
2	12	Mcarthur
3	76	Alan Smiles
4	76	David Taylor
5	100	Mathew Arnold
6	100	Kreisler
7	127	Agatha Christy
8	140	Keith Davis