mysql sequence 产号 模仿oracle

-- 创建
drop table if exists sequence;   
create table sequence (       
seq_name    VARCHAR(50)  NOT NULL,    -- 序列名称       
current_val     INT         NOT NULL,             -- 当前值       
increment_val   INT         NOT NULL    DEFAULT 1, -- 步长(跨度)       
PRIMARY KEY (seq_name));


create function currval(v_seq_name VARCHAR(50))   
returns integer(11) 
begin
 declare value integer;
 set value = 0;
 select current_val into value  from sequence where seq_name = v_seq_name;
   return value;
end;

create function nextval (v_seq_name VARCHAR(50)) returns integer(11) 
begin
    update sequence set current_val = current_val + increment_val  where seq_name = v_seq_name;
    return currval(v_seq_name);
end;

-- 使用
INSERT INTO sequence VALUES ('seq_test', '0', '1');

select currval('seq_test');

select nextval('seq_test');

mysql数据库实现nextval函数 - 简书