mysql实现nextVal功能

首先创建表：

CREATE TABLE `sys_sequence` (
   `NAME` varchar(50) NOT NULL,
   `CURRENT_VALUE` int(11) NOT NULL DEFAULT '0',
   `INCREMENT` int(11) NOT NULL DEFAULT '1',
   PRIMARY KEY (`NAME`)
 )

插入记录

INSERT INTO SYS_SEQUENCE(NAME,CURRENT_VALUE,INCREMENT) VALUES('TBL_FS', 1,1)

DELIMITER $$

DROP FUNCTION IF EXISTS `currval`$$

CREATE DEFINER=`root`@`%` FUNCTION `currval`(seq_name VARCHAR(50)) RETURNS INT(11)
BEGIN
DECLARE VALUE INTEGER;
SET VALUE=0;
SELECT current_value INTO VALUE
FROM sys_sequence 
WHERE NAME=seq_name;
RETURN VALUE;
END$$

DELIMITER ;

查询当前记录：

select currval('TBL_FS');

如果出现Error Code: 1449 The user specified as a definer ('root'@'%') does not exist  错误，则执行如下sql：

grant all privileges on *.* to root@"%" identified by "password"; 
flush privileges;  

继续执行当前记录sql则成功

创建nextval函数

DELIMITER $$
DROP FUNCTION IF EXISTS `nextval`$$

CREATE DEFINER=`root`@`%` FUNCTION `nextval`(seq_name varchar(50)) RETURNS int(11)
BEGIN
UPDATE sys_sequence
SET CURRENT_VALUE = CURRENT_VALUE + INCREMENT
where name=seq_name;
return currval(seq_name);
END$$

执行nextval函数

select nextval('tbl_fs')