Hi Zahran
Little quote from BOL
When an MD5 hash algorithm is specified, the probability of HashBytes returning the same result for two different inputs is much lower than that of CHECKSUM.
Keep in mind. A hash is as unique as possible, but it's not a guarantee for real uniqueness. If you have a VARCHAR(100) column it represents much more possible values than an INT.
You can use HASHBYTES or BINARY_CHECKSUM to get a better hash than old CHECKSUM function.
SELECT
HASHBYTES('MD5', CustomerNo + Address)
,BINARY_CHECKSUM(CustomerNo, Address)
,CHECKSUM(CustomerNo, Address)
FROM @checksum
Anyway, a hash will never be a 100% guarantee for uniqueness. If you need unique values use an IDENTITY column or a GUID.
Greets
Flo
Edit: Dang! Sorry, didn't notice this is the 2000 forum. Probably the new functions are not available...