The following Microsoft SQL Server T-SQL code examples demonstrate how to create a sequence number for an ordered set without ties:

-- T-SQL SELF-JOIN usage for autonumbering

USE Northwind;

SELECT   SeqNo = count(* ),

         Name = a.LastName + ', ' + a.FirstName

FROM     Northwind.dbo.Employees a

         INNER JOIN Northwind.dbo.Employees b

           ON a.LastName + ', ' + a.FirstName >= b.LastName + ', ' + b.FirstName

GROUP BY a.LastName + ', ' + a.FirstName

ORDER BY a.LastName + ', ' + a.FirstName

/*

SeqNo Name

1     Buchanan, Steven

2     Callahan, Laura

3     Davolio, Nancy

4     Dodsworth, Anne

5     Fuller, Andrew

....

*/

-- SQL Server 2005 and on - ROW_NUMBER ranking function

SELECT      SeqNo = ROW_NUMBER() OVER (ORDER BY LastName,FirstName),

            Name = p.LastName + ', ' + p.FirstName,

            BusinessEntityID

FROM AdventureWorks2008.Person.Person p

/*

SeqNo Name              BusinessEntityID

1     Abbas, Syed       285

2     Abel, Catherine   293

3     Abercrombie, Kim  295

4     Abercrombie, Kim  2170

5     Abercrombie, Kim  38

*/