Usage of sequence in SQL Server 2012

CREATE SEQUENCE dbo.OrderIDs
    AS INT
    MINVALUE 1
    NO MAXVALUE
    START WITH 1;

SELECT NextOrderID = NEXT VALUE FOR dbo.OrderIDs
UNION ALL     SELECT NEXT VALUE FOR dbo.OrderIDs
UNION ALL     SELECT NEXT VALUE FOR dbo.OrderIDs;

Results:

NextOrderID
-----------
1
2
3

See here for original source and more examples. The page refers to SQL Server Denali which is the beta of SQL 2012 but the syntax is still the same.

One of the ways I leverage the SEQUENCE command is for reference numbers in an ASP/C# detailsview page (as an example). I use the detailsview to enter requests into a database and the SEQUENCE command serves as the request/ticket number for each request. I set the inital sequence command to start with a specific number and increment by 1 for each request.

If I present these requests in a gridview I make the SEQUENCE reference numbers appear but don't make them editable. Its great for a reference number when records are similar with other fields in the database. It's also perfect for customers when they have questions about a specific entry in a given database. This way I have a unique number per entry no matter if the rest of the information is identical or not.

Here's how I generally leverage the SEQUENCE command:

CREATE SEQUENCE blah.deblah
     START WITH 1
     INCREMENT BY 1
     NO CYCLE
     NO CACHE

In short, I start my sequence at #1 (you can choose any number you want to start with) and it counts upwards in increments of 1. I don't cycle the sequence numbers when they reach the system max number.