How to obtain underlying provider errors by using ADO.NET in Visual C++ .NET

Managed providers can raise several exceptions. To obtain more detailed information about the cause, you need access to provider-specific error information. This article shows how to gather this information.

Requirements

The following list outlines the recommended hardware, software, network infrastructure, and service packs that are required:

• Microsoft .NET Framework
• Microsoft Visual C++ .NET

This article assumes that you are familiar with the following topics:

• Exceptions and error handling
• Microsoft OLE DB

Technique description

You must wrap your code in a "try... catch" block to catch the exception and process the error collection from the OLEDBException.

Create project and add code

1. Create a new Managed C++ application. Name the project ProviderError.
2. Open the ProviderError.CPP file. Copy the following code and paste it in to replace the default code built in by Microsoft Visual Studio .NET:

   
   #include "stdafx.h"
   #using <mscorlib.dll>
   #using <System.dll>
   #using <System.Data.dll>
   
   using namespace System;
   using namespace System::Data::OleDb;
   
   // This is the entry point for this application
   #ifdef _UNICODE
   int wmain(void)
   #else
   int main(void)
   #endif
   {
           OleDbConnection *myCn = new OleDbConnection("Provider=SQLOLEDB.1;Data Source=MyWrongServerName");
           try
   	{
               myCn->Open();
   	}
           catch(OleDbException *ex)
   	{
               Int32 i;
               for (i = 0; i <= ex->Errors->Count - 1; i++)
   	   {
   				Console::WriteLine("Index # {0} \n Message: {1} \n Native: {2}" 
   					"\n Source: {3} \n SQL: {4} \n", i.ToString(), ex->Errors->Item[i]->Message, 
   					ex->Errors->Item[i]->NativeError.ToString(), ex->Errors->Item[i]->Source, 
   					ex->Errors->Item[i]->SQLState);
   	   }
   	}
   
   	return 0;
   }

3. On the Debug menu, click Run without Debugging to run the application. A console window that contains the provider error should appear after about 10 to 15 seconds.

Troubleshooting

If you have a server called "MyWrongServerName", you may not get an error message.