DELIMITER $$

DROP PROCEDURE IF EXISTS `testdb`.`code` $$
CREATE PROCEDURE `code`(in sno char(10))
BEGIN
  DECLARE done INT DEFAULT 0;
  declare inta,seq0,qseq int;
  declare flag char(1);

  declare curseq cursor for select seq from sto_iproduces where pslipno =sno;
  DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1;

  set inta=0,qseq=1,seq0=0,flag='0';

  open    curseq;
  fetch   curseq into seq0;
  while done=0 do
        set inta=inta+1;
        set flag='2';

        if seq0<>inta then
           set qseq=inta;
           set flag='1';
           set done=1;
       end if;
  fetch   curseq into seq0;
  end while;

  close curseq;

if flag='2'  then
  set qseq=inta+1;
end if;
   select qseq;
END $$

DELIMITER ;
注:1.pslipno的參數為sno,可別定義與pslipno相同,或者資料表中的欄位名同名
      2.seq為欄位名,其變數為seq0若設為一樣則沒有值
      3.此範例應用於:資料表有slipno+seq為主KEY,要找seq所缺號