RAND
Returns a random float or double between 0 and 1.0.
Syntax
RAND ( [seed] )
Arguments
seed: any valid numerical value.
Return type
A random float or double between 0 and 1.0.
Examples
In this example, note how the values in the rand() column differ across calls, and rand(1234) remains the same.
CREATE TABLE randos (i bigint primary key); INSERT INTO randos VALUES (1), (2), (3), (4);
SELECT i, RAND(), RAND(1234) FROM randos; +---+---------------------+----------------------+ | i | RAND() | RAND(1234) | +---+---------------------+----------------------+ | 1 | 0.060627053578449 | 0.9903344706785644 | | 2 | 0.6705938059950731 | 0.9595036873433918 | | 3 | 0.0033184406209954 | 0.30311394845511597 | | 4 | 0.16278354692338404 | 0.021165254013737034 | +---+---------------------+----------------------+
SELECT i, RAND(), RAND(1234) FROM randos; +---+--------------------+----------------------+ | i | RAND() | RAND(1234) | +---+--------------------+----------------------+ | 1 | 0.4223319269518615 | 0.9903344706785644 | | 2 | 0.0984310326439255 | 0.9595036873433918 | | 3 | 0.5731110152577712 | 0.30311394845511597 | | 4 | 0.3304480903355833 | 0.021165254013737034 | +---+--------------------+----------------------+
SELECT i, CEIL(RAND() * 100) FROM randos; +---+--------------------+ | i | CEIL(RAND() * 100) | +---+--------------------+ | 1 | 1 | | 2 | 90 | | 3 | 77 | | 4 | 80 | +---+--------------------+
SELECT i FROM randos ORDER BY RAND(); +---+ | i | +---+ | 4 | | 1 | | 2 | | 3 | +---+