第一次写MySQL FUNCTION，一直报错，

Err] 10 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '`company_id` int) RETURNS varchar(20) CHARSET utf8

BEGIN

本来的函数：

CREATE DEFINER=`33323`@`%` FUNCTION `createSaleCode`(`benginStr` varchar,`company_id` int) RETURNS varchar(20) CHARSET utf8 
BEGIN 
 DECLARE nearnum VARCHAR(20); 
 DECLARE nowdatepre VARCHAR(20); 
 DECLARE numout VARCHAR(20); 
 SELECT a.sale_code INTO nearnum FROM d_sale a WHERE a.company_id = company_id ORDER BY a.sale_id DESC limit 1; 
 SELECT concat(extract(year_month from now()),LPAD(extract(day from now()), 2, 0)) INTO nowdatepre; 
 IF locate(nowdatepre,nearnum)>0 
 THEN 
 set numout = nearnum +1; 
 ELSE 
 set numout = concat(beginStr,nowdatepre,'00001'); 
 END IF; 
 RETURN numout; 
END 

这段函数在Navicat上边执行不起来，在多次尝试之后将代码修改为以下：

delimiter $$ 
CREATE DEFINER=`12212`@`%` FUNCTION createSaleCode(benginStr varchar(20),company_id int(11) ) RETURNS varchar(20) CHARSET utf8 
BEGIN 
 DECLARE nearnum VARCHAR(20); 
 DECLARE nowdatepre VARCHAR(20); 
 DECLARE numout VARCHAR(20); 
 SELECT a.sale_code INTO nearnum FROM d_sale a WHERE a.company_id = company_id ORDER BY a.sale_id DESC limit 1; 
 SELECT concat(extract(year_month from now()),LPAD(extract(day from now()), 2, 0)) INTO nowdatepre; 
 IF locate(nowdatepre,nearnum)>0 
 THEN 
 set numout = nearnum +1; 
 ELSE 
 set numout = concat(beginStr,nowdatepre,'00001'); 
 END IF; 
 RETURN numout; 
END$$ 
delimiter ; 

问题解决。

默认情况下，delimiter是分号;。

总结