曾以為Windows版本的MySQL存在不能使用UDF的BUG諸提交了一個bug報告。不過
似乎發現是我搞錯了，MySQL的技術支持人員給了非常完美的解答，同大家分享
一下。下邊是原文回復 :)
Sorry this isn't 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 MySQLd.dsw workspace.
- Add New project to the workspace
- Project name: my_udf
- Select Win32 Dynamic-Link Library
- Click OK
- Select An Empty DLL project
- Click Finish
- Click OK
- Add a new file called my_udf.cpp 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_udf.def
- Edit the above file with the below contents:
LIBRARY UDF_EXAMPLE
DESCRIPTION 'Example Using UDF with VC++'
VERSION 1.0
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
e.g: ../include
- Press F7 for to build the DLL.
- Copy the my_udf.dll to the environment path directory:
\winnt\system32 for example.
