I once thought that there was a bug in the Windows version of MySQL that could not use UDF, so I submitted a bug report. However
it seems that I made a mistake. The technical support staff of MySQL gave a perfect answer and I would like to share it with you
. Below is the original reply:)
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:
winntsystem32 for example.
- Start the mysql client and issue:
C:mysql-udf in>mysql -uroot -p