Posted by Erland Sommarskog on 06/09/07 21:19

Hugo Kornelis (hugo@perFact.REMOVETHIS.info.INVALID) writes:
> On Sat, 9 Jun 2007 19:19:45 +0000 (UTC), Erland Sommarskog wrote:
>
>>chico_yallin@yahoo.com (chico_yallin@yahoo.com) writes:
>>> I just wana make a random id number based on4 digits-for examples??
>>
>>checksum(newid()) is better than the rand() function.
>
> Hi Erland,
>
> What exactly makes checksum(newid()) better than rand() ?

Here is a practical reason:

select rand(), checksum(newid())
from (select n = 1 union all select 2 union all select 4) as x

I believe that there also issues with the randomness of rand(), although
I don't remember the exact details. Steve Kass knows the full story.



--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx

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