Generate random bit strings in MySQL

GenerateRandomBinaryCode.sql

DELIMITER $$
CREATE DEFINER=`root`@`localhost` FUNCTION `random_str`() RETURNS char(16) CHARSET utf8mb4 COLLATE utf8mb4_unicode_ci
BEGIN
  DECLARE chars varchar(16);
  DECLARE rs varchar(16);
  SET rs = '';
  SET chars = 'ABCDEF1234567890';
  WHILE (LENGTH(rs) < 16) DO
    SET rs = CONCAT(rs, SUBSTRING(chars, RAND() * LENGTH(chars), 1));
  END WHILE;
  RETURN rs;
END$$


CREATE DEFINER=`root`@`localhost` PROCEDURE `fill_test`(IN `cnt` INT UNSIGNED)
    NO SQL
BEGIN
    DECLARE c int;
    DECLARE rs varchar(16);
    SET c = 0;
    while (c < cnt) DO
        set rs = random_str();
        INSERT INTO test_random_binary_codes (hash) VALUES (rs);
        set c = c + 1;
    end while;
END$$


DELIMITER ;