T-SQL Case statement strange behavior with newid() as randomness source

Question

I\'m using SQL Server 2012.

If I do the following to get a list of random-ish numbers in the range [1,3], it works just fine:

SELECT TOP 100 
    ABS         


        

Answer 1

I cant tell you why, it is indeed strange, but I can give you a workaround. Select the random values into a cte before trying to use them

;with rndsrc(value_of_rand) as
(
SELECT TOP 100 
    ABS(CHECKSUM(NEWID()))%3 + 1
FROM sys.objects
)
SELECT TOP 100 
CASE value_of_rand
    WHEN 1
        THEN 'one'
    WHEN 2
        THEN 'two'
    WHEN 3
        THEN 'three'
    ELSE
        'that is strange'
END [value_of_case]
from rndsrc

No more "that is strange"