查询表获取自增值

用于文件的浏览量，某值不重复均可

drop table if exists `sequence`;

create table sequence (

`seq_name`        VARCHAR(50) NOT NULL COMMENT '序列名称',

`current_val`    INT        NOT NULL COMMENT '当前值',

`increment_val`  INT        NOT NULL DEFAULT 1 COMMENT '步长',

PRIMARY KEY (`seq_name`) )ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='序列表';

delimiter $$

create function currval(v_seq_name VARCHAR(50))

returns integer

begin

declare value integer;

set value = 0;

select current_val into value  from sequence where seq_name = v_seq_name;

return value;

end$$

demiliter;

delimiter $$

create function nextval (v_seq_name VARCHAR(50))

returns integer

begin

update sequence set current_val = current_val + increment_val  where seq_name = v_seq_name;

return currval(v_seq_name);

end$$

查询语句：select nextval('seq_test1_num1');