曾以为Windows版本的MySQL存在不能使用UDF的BUG诸提交了一个bug报告不过似乎发现是我搞错了MySQL的技术支持人员给了非常完美的解答同大家分享一下下边是原文回复
用户你好抱歉这并不是一个bug下面我粘贴一个以前为某个客户做的简例假设你有了VC++源码分发并且有一个正常运行的MySQL服务器
我将创建一个UDF它将一个名字:
注意:例子非常简陋目的是让你了解该如何处理手头的UDF
打开 mysqlddsw 工作区
添加新项目到这个工作区
Project name: my_udf // 项目名称:my_udf
选择 Win DynamicLink Library // Win动态连接库
点击 OK
选择 An Empty DLL project // 一个空DLL项目
点击 Finish
点击 OK
添加新文件 my_udfcpp 到项目中:
#include
#include
#include
extern C {
char *my_name(UDF_INIT *initid UDF_ARGS *args char *is_null
char *error);
// 兼容C
}
char *my_name(UDF_INIT *initid UDF_ARGS *args char *is_null
char *error)
{
char * me = my name;
return me;
// 调用此UDF将返回 my name
}
按 Ctrl+N 来创建一个新文件
选择 text 类型
File name: my_udfdef file://文件名:my_udfdef
按照下边的内容编辑文件
LIBRARY UDF_EXAMPLE
DESCRIPTION Example Using UDF with VC++
VERSION
EXPORTS
my_name
右击my_udf项目并选择Settings
点 C/C++ 选项卡
选择 General
添加宏 HAVE_DLOPE 到预处理器定义
选择 Preprocessor
添加头文件路径: Additional Include directories
例如: /include
按 F 去编译成 DLL
复制 my_udfdll 到环境变量path定义过的目录
比如 \winnt\system
打开mysql客户端
C:\mysqludf\bin>mysql uroot p
Enter password:
Welcome to the MySQL monitor Commands end with ; or \g
Your MySQL connection id is to server version: maxnt
Type help; or \h for help Type \c to clear the buffer
mysql> CREATE FUNCTION my_name RETURNS STRING SONAME my_udfdll;
Query OK rows affected ( sec)
mysql> select my_name();
mysql> drop function my_name;
Query OK rows affected ( sec)
以下是MySQL技术人员的回信原文
Sorry this isnt a bug
Below I pasted a sample I did sometime ago for another user:
Ok Assuming you have VC++ and the source distribution and a server
running
I will create a UDF that returns a name:
Note: the sample is ugly but the purpose here is to show you how
to handle the UDF
Open the mysqlddsw workspace
Add New project to the workspace
Project name: my_udf
Select Win DynamicLink Library
Click OK
Select An Empty DLL project
Click Finish
Click OK
Add a new file called my_udfcpp to the project:
#include
#include
#include
extern C {
char *my_name(UDF_INIT *initid UDF_ARGS *args char *is_null
char *error);
}
char *my_name(UDF_INIT *initid UDF_ARGS *args char *is_null
char *error)
{
char * me = my name;
return me;
}
Type Ctrl+N for to create a new file
Select text type
File name: my_udfdef
Edit the above file with the below contents:
LIBRARY UDF_EXAMPLE
DESCRIPTION Example Using UDF with VC++
VERSION
EXPORTS
my_name
Right Click the my_udf project and select Settings
Click the C/C++ tab
Select General in the Category Combo
Add the macro HAVE_DLOPEN to the PreProcessor definition
Select Preprocessor in the Category Combo
Add the include path to the text box: Additional Include directories
eg: /include
Press F for to build the DLL
Copy the my_udfdll to the environment path directory:
\winnt\system for example
Start the mysql client and issue:
C:\mysqludf\bin>mysql uroot p
Enter password:
Welcome to the MySQL monitor Commands end with ; or \g
Your MySQL connection id is to server version: maxnt
Type help; or \h for help Type \c to clear the buffer
mysql> CREATE FUNCTION my_name RETURNS STRING SONAME my_udfdll;
Query OK rows affected ( sec)
mysql> select my_name();
mysql> drop function my_name;
Query OK rows affected ( sec)
