java基于数据库实现全局唯一ID的示例

CREATE DEFINER=`root`@`localhost` FUNCTION `currval`(`keyname` varchar(50)) RETURNS int
BEGIN
   DECLARE v int;
	 SET v=0;
	 SELECT CURR_VAL INTO v from sequence WHERE SEQNAME=keyname;
	 RETURN v;
END

CREATE DEFINER=`root`@`localhost` FUNCTION `nextval`(seq VARCHAR(50)) RETURNS int
BEGIN
   UPDATE sequence SET CURR_VAL=CURR_VAL+INCREMENT_VAL WHERE SEQNAME=seq;
	 RETURN currval(seq);
END

select nextval(#{seq})