如何从自定义 ODBC 驱动程序创建 DSN？

Question

For the last couple of weeks I'm struggling with ODBC in general. Made some progress but now I am stuck in setting up a dsn with custom ODBC driver.

What I understood, looking through postgres open source code. I need to make a dll that contains two functions 1.ConfigDsn 2ConfigDriver

Here is example of my code

 #include "pch.h"
 #include <Windows.h>



 BOOL WINAPI DllMain(HANDLE hInst, ULONG ul_reason_for_call, LPVOID lpReserved)
 {


 switch (ul_reason_for_call)
 {
 case DLL_PROCESS_ATTACH:
 case DLL_THREAD_ATTACH:
 case DLL_THREAD_DETACH:
 case DLL_PROCESS_DETACH:
    break;
 }
 return TRUE;
}


 BOOL ConfigDSN(
  HWND     hwndParent,
  WORD     fRequest,
  LPCSTR   lpszDriver,
  LPCSTR   lpszAttributes) {
  MessageBox(NULL, L"TU", L"OVDJE", 0);
  return TRUE;
 }

 BOOL ConfigDriver(
  HWND    hwndParent,
  WORD    fRequest,
  LPCSTR  lpszDriver,
  LPCSTR  lpszArgs,
  LPSTR   lpszMsg,
  WORD    cbMsgMax,
  WORD* pcbMsgOut) {
  MessageBox(NULL, L"TU", L"OVDJE", 0);
  return TRUE;
 }

When I try to Add a new DSN none of the message box shows.

If I add Message box call inside a DLLMain function, then the message box is displayed. I'm assuming I missing a fundamental c++ knowledge in building dlls. Because I saw some .def files in resource folder inside postgres source code.

My question is how I need to make this dll so I could create a DSN with my own driver ?

Answer 1

Since you are building C++ code, all function names will be mangled . The ODBC functionslity probably expects to use the un-mangled names.

Use extern "C" to prevent name mangling:

extern "C" BOOL ConfigDSN(...) { ... }

extern "C" BOOL ConfigDriver(...) { ... }