PostgreSQL: How to generate a random string

If you want to mock a large amount data, you may need to generate some random strings.

random_string function

CREATE OR REPLACE FUNCTION random_string(integer) RETURNS text AS $body$
    SELECT array_to_string(array(SELECT substring('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz' FROM (ceil(random()*62))::int FOR 1) FROM generate_series(1, $1)), '');
$body$ LANGUAGE SQL VOLATILE;

How to use

SELECT randome_string(10);