MySQL RAND() Function

Return a random decimal number (no seed value - so it returns a completely random number >= 0 and <1):

SELECT RAND();

Definition and Usage

The RAND() function returns a random number between 0 (inclusive) and 1 (exclusive).

RAND(seed)

Parameter	Description
seed	Optional. If seed is specified, it returns a repeatable sequence of random numbers. If no seed is specified, it returns a completely random number

Works in:	From MySQL 4.0

Return a random decimal number (with seed value of 6):

SELECT RAND(6);

Return a random decimal number >= 5 and <10:

SELECT RAND()*(10-5)+5;

Return a random number >= 5 and <=10:

SELECT FLOOR(RAND()*(10-5+1)+5);