PRB: DataLink Type Library Moved From MSDASC.DLL To OLEDB32.DLL In ADO 2.1

• ActiveX Data Objects (ADO), version 2.1

SYMPTOMS

An attempt to #import Msdasc.dll to gain access to the DataLink COM object and OLE DB connection dialog results in the following compiler error in Visual C++:

fatal error C1083: Cannot open type library file: 'C:\Program Files\Common Files\System\OLE DB\msdasc.dll': Error loading type library/DLL.

CAUSE

The type library for the DataLink COM object is no longer in Msdasc.dll. The type library has been moved into Oledb32.dll.

RESOLUTION

Change Msdasc.dll to oledb32.dll in your #import statement.

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a blank console project and insert a new .cpp file named Main.cpp



2. Insert the code below.



3. Switch the #import of Msdasc.dll with Oledb32.dll in order to use the DataLink COM object with ADO 2.1.

   #include "stdio.h"
   #include "conio.h"

   // #import ADO.
   #undef EOF
   #import "c:\program files\common files\system\ado\msado15.dll"\<BR/>
no_namespace

   // In ADO 2.0, you would use the following #import statement.
   #import "c:\program files\common files\system\ole db\msdasc.dll"\ no_namespace

    // Copy and paste of this code might result in escape sequence error
  //during compile time. You can either write the whole #import statement 
//in one line, or make sure that there is no space after escape sequence                                              

//"\".   
   
   // In ADO 2.1 use the following #import statement.
   //#import "c:\program files\common files\system\ole db\oledb32.dll" \ 
   //  no_namespace

   void main() 
   {
     HRESULT hr;
     IDataSourceLocatorPtr dlPrompt = NULL;
     _ConnectionPtr conn = NULL;
     _RecordsetPtr rs = NULL;

     // Initialize COM
     ::CoInitialize( NULL );

     try
     {
       // Instantiate DataLinks object.
       hr = dlPrompt.CreateInstance( __uuidof( DataLinks ) );
       if ( FAILED( hr ) ) throw( _com_error( hr, NULL ) );

       // Prompt for connection information.
       conn = dlPrompt->PromptNew();

       // If connection object is NULL, user cancelled.
       if ( NULL == conn ) goto Exit;

       // Open connection (connection returned by DataLinks is just
       // a holder for the returned ConnectionString).
       conn->Open( conn->ConnectionString, L"", L"", -1 ); 

       // Get a list of tables and dump list to console.
       rs = conn->OpenSchema( adSchemaTables );
       printf( "Listing tables:\n" );
       while ( !rs->EOF )
       {
         printf( "%s\n", 
             (char*) (_bstr_t) 
             rs->Fields->Item[L"TABLE_NAME"]->Value );
         rs->MoveNext();
       }
     }
     catch ( _com_error &ce )
     {
       // Trace COM error information.
       printf( "\nCom Exception Information\n" );
       printf( "Description : %s\n",   (char*) ce.Description()  );
       printf( "Message     : %s\n",   (char*) ce.ErrorMessage() );
       printf( "HResult     : 0x%08x\n", ce.Error() );
     }
   Exit:
     printf( "DataLink test complete. Press any key to exit test.\n" );
     _getch();
   } 

Additional query words: prompt oledb user connection dialog

Keywords : kbADO210 kbDatabase kbGrpVCDB
Version : WINDOWS:2.1
Platform : WINDOWS
Issue type : kbprb