RAND not different for every row in T-SQL UPDATE

Question

I have the follow T-SQL to update a table with test data:

UPDATE
SomeTable
SET
    Created = GETDATE ( ) - CAST ( RAND ( ) * 365 AS int ) ,
    LastUpdated =         


        

Answer 1

if you only want days from the past year use this (based on @gbn's answer):

select GETDATE ( ) - ABS( CHECKSUM(NEWID()) % 365 )

Answer 2

Use RAND(CHECKSUM(NEWID()))

• NEWID returns a GUID
• CHECKSUM makes it int, randomly
• The int seeds the RAND

In your case, you could modulo the checkum because CHECKSUM(NEWID()) is already random.

CHECKSUM(NEWID()) % 365