Saturday, 17 January 2009

Generate a unique number in Sql Server 2005

We often find ourselves in the need of generating unique numbers in our database applications.

Let us quickly take a tour of how to do that using Sql server 2005.

SQL Server contains the NEWID() function. This function creates a unique value of type uniqueidentifier. We can use this function in several ways to generate unique numbers to suit our requirements :

Generate GUID's :

UniqueIndentifiers are also knows as GUID's. To generate a GUID use :

SELECT NEWID() as GuidNo

generates FBF2D8E9-F8BE-4F0B-9D49-7CA7C2E3F22C on my machine

Generate only digits :

SELECT ABS(CAST(CAST(NEWID() AS VARBINARY(5)) AS Bigint)) as UniqueNo

generates 427357674589 on my machine

Generate fixed digit unique numbers :

At times, we may also need to generate fixed digit numbers. You can do that in the following manner :

SELECT REPLACE(STR(CAST(CAST(NEWID() AS binary(5)) AS bigint),12),0,0)

generates 470370453006 on my machine


If it helped you ....please drop ur comments !!

2 comments:

  1. THanks for the help

    ReplyDelete
  2. Hi Sanjeev

    Thank you for the code sample. Will the "Only Digits" and "Fixed Digits" options generate numbers like the one you find on the EBay website for each item?

    ReplyDelete