Membuat Autonumbering di Mysql

CREATE PROCEDURE `RepairPosting`(IN RekAwal VARCHAR(20))
    NOT DETERMINISTIC
    SQL SECURITY DEFINER
    COMMENT ''
BEGIN

     DECLARE RekMax INT(20);
     DECLARE KodeBaru VARCHAR(8);
     DECLARE urut INT;
     DECLARE RekJadi VARCHAR(20);
     
     select max(right(kre_rekening, 5)) INTO RekMax
     from data_kredit_master
     where LEFT(kre_rekening, 6) = LEFT(RekAwal, 6);

     SET urut = IF(RekMax IS NULL, 1, RekMax + 1);
     SET KodeBaru = LPAD(urut, 5, 0);
     SET RekJadi = CONCAT(LEFT(RekAwal, 6), KodeBaru);
     
     UPDATE `data_kredit_master`
     SET kre_rekening = RekJadi WHERE kre_rekening = RekAwal;
        
END;