MySQL 4.1.7-log创建函数遇ERROR 1064，求语法修正方案

服务器环境信息 #

C:\Appserv\mysql\bin\mysql.exe  Ver 14.7 Distrib 4.1.7, for Win95/Win98 (i32)

Connection id:          296 
Current database: 
Current user:           ODBC@localhost 
SSL:                    Not in use 
Using delimiter:     ; 
Server version:         4.1.7-log 
Protocol version:       10 
Connection:             localhost via TCP/IP 
Server characterset:    latin1 
Db     characterset:    latin1 
Client characterset:    latin1 
Conn.  characterset:    latin1 
TCP port:               3306

原函数创建语句 #

CREATE FUNCTION IF NOT EXISTS isNumeric (input VARCHAR(255))
RETURNS INT  DETERMINISTIC  RETURN input REGEXP '^[0-9]+\\\\.?[0-9]*$';

错误日志 #

ERROR 1064 (42000): 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 'IF NOT EXISTS isNumeric (input VARCHAR(255))

修正方案 #

MySQL 4.1版本不支持CREATE FUNCTION IF NOT EXISTS语法，该语法在MySQL 5.0及以上版本才被引入。直接去掉IF NOT EXISTS即可修复语法错误，修正后的语句如下：

CREATE FUNCTION isNumeric (input VARCHAR(255))
RETURNS INT DETERMINISTIC 
RETURN input REGEXP '^[0-9]+\\.?[0-9]*$';

内容的提问来源于stack exchange，提问作者Rona Idea