PostgreSQL random() Function

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

`random()` Syntax

This is the syntax of the PostgreSQL random() function:

random()

Parameters

The PostgreSQL random() function does not have any parameters.

Return value

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

The return value of random() is a random decimal between 0 (inclusive) and 1 (exclusive). If you want to return random numbers in other intervals (such as m and n), please use the following formulas.

A random number between m and n: random() * (n - m) + m
A random integer between m and n: FLOOR(random() * (n - m + 1) + m)

If you want to get a stable random sequence, use the random() function in conjunction with the setseed() function.

`random()` Examples

Get a random number between 0 and 1

This example shows how to use the random() function function to get a random number between 0 and 1.

SELECT
    random(),
    random(),
    random(),
    random();

-[ RECORD 1 ]---------------
random | 0.3029171607224228
random | 0.42633738304023794
random | 0.584824959131069
random | 0.7533572011921841

Get a random number between 10 and 20

This example shows how to use the random() function function to get a random number between 10 and 20.

SELECT
    random() * (20 - 10) + 10 AS "10 <= x < 20",
    random() * (20 - 10) + 10 AS "10 <= x < 20",
    random() * (20 - 10) + 10 AS "10 <= x < 20",
    random() * (20 - 10) + 10 AS "10 <= x < 20";

-[ RECORD 1 ]+-------------------
10 <= x < 20 | 19.504483402831525
10 <= x < 20 | 13.118109640092719
10 <= x < 20 | 17.609356732100565
10 <= x < 20 | 10.092857779143252

Get a random integer between 10 and 20

This example shows how to use random() the and floor() to get a random integer between 10 and 20.

SELECT
    floor(random() * (20 - 10 + 1) + 10) AS "10 <= x < 20",
    floor(random() * (20 - 10 + 1) + 10) AS "10 <= x < 20",
    floor(random() * (20 - 10 + 1) + 10) AS "10 <= x < 20",
    floor(random() * (20 - 10 + 1) + 10) AS "10 <= x < 20";

-[ RECORD 1 ]+---
10 <= x < 20 | 15
10 <= x < 20 | 17
10 <= x < 20 | 12
10 <= x < 20 | 14

random() Syntax