Generate unique random numbers using SQL

Question

I have some SQL code which generates random numbers using the following technique:

DECLARE @Random1 INT, @Random2 INT, @Random3 INT, @Random4 INT, @Random5 I         


        

Answer 1

I guess you could do something like this much simpler and much easier

DECLARE @Upper INT;
DECLARE @Lower INT;
SET @Lower = 1;     /* -- The lowest random number */
SET @Upper = 49;    /* -- The highest random number */
    
    
SELECT @Lower + CONVERT(INT, (@Upper-@Lower+1)*RAND());

For getting a random number without repetition, this will do the job

WITH CTE 
AS
(
    SELECT  randomNumber, COUNT(1) countOfRandomNumber
    FROM (
    SELECT ABS(CAST(NEWID() AS binary(6)) %49) + 1 randomNumber
    FROM sysobjects
    ) sample
    GROUP BY randomNumber
)
SELECT TOP 5 randomNumber
FROM CTE
ORDER BY newid() 

To set the highest limit, you can replace 49 with your highest limit number.