创建currvar、nextvar函数

MySQL序列函数创建

转载于 2017-08-14 16:36:00 发布 · 104 阅读

0 ·

CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/oujiao/p/7358587.html

本文介绍了在MySQL中如何创建currval和nextval两个序列值函数，通过这些函数可以实现在不同表间共享序列值，适用于需要生成唯一标识符的场景。

use miniloan;
set global log_bin_trust_function_creators = 1;
DELIMITER $$
CREATE DEFINER='miniloan'@'%' FUNCTION currval (name VARCHAR(50)) RETURNS int(11)
DETERMINISTIC
BEGIN 
DECLARE VALUE INTEGER; 
SET VALUE = 0; 
SELECT seq_value INTO VALUE

FROM sequence 
WHERE seq_name = name; 
RETURN VALUE; 
END $$

use miniloan;
set global log_bin_trust_function_creators = 1;
DELIMITER $$
CREATE DEFINER='miniloan'@'%' FUNCTION nextval(name VARCHAR(50)) RETURNS int(11)
    DETERMINISTIC
BEGIN  
         UPDATE sequence  
                   SET seq_value = seq_value + 1  
                  WHERE seq_name = name;  
         RETURN currval(name);  
END $$

转载于:https://www.cnblogs.com/oujiao/p/7358587.html