random_key.sql

CREATE OR REPLACE FUNCTION unique_key_create()
  RETURNS text AS
$BODY$
DECLARE
	_length INTEGER := 10; --from backend settings
	_key TEXT;
BEGIN
	WHILE TRUE LOOP 
		SELECT array_to_string( 
		    ARRAY (SELECT substring('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789' 
        		   FROM (ceil(random()*62))::int FOR 1)
        FROM generate_series(1, _length)), '') INTO _key;
        BEGIN
            INSERT INTO "unique_key" ("key") VALUES (_key);
            RETURN _key;
        EXCEPTION WHEN unique_violation THEN
            -- pass
        END;
	END LOOP;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION get_key()
  OWNER TO postgres;