C++ importing and using ADO

Question

I have two short questions involving importing and using ADO in a C++ project. I am not experienced with ADO in any form.

First, for the time being the database aspect of my program need only run on Windows. Is it enough to test if _WIN32 or _WIN64 is defined before running ADO specific code, or are there better approaches? I am using Visual C++ 2010 Express as my compiler.

Second, I am following this page as my guide. I've included the #import statement for msado15.dll. The #import directive is underlined red, and the error I receive when hovering over it says "...cannot open source file path/to/msado15.tlh," and any ADO stuff I copy into the source stays red underlined. I've checked the directory listed in the error message and msado15.tlh is there, if that matters. Also, the program compiles (it crashes though after executing, but that's something else I'll diagnose separately).

I'm pretty clueless about why this is happening. Any help or advice would be appreciated.

Answer 1

The way we do it, we add the following to out VC++ Directories / Include files

$(ProgramFiles)\Common Files\System\ado

And then we import like this

in the header:

#import "msado15.dll" rename_namespace("ADO") rename("EOF", "EndOfFile") no_implementation

At the top of the cpp file

#import "msado15.dll" rename_namespace("ADO") rename("EOF", "EndOfFile") implementation_only

A little different, since we prefer to keep the namespace, and use a different EOF rename.

C++ Import help on MSDN

C++ Import Attributes on MSDN

Answer 2

I had the same problem when I started with ADO. (red underlined, can't find...) It drove me nuts but after simply compiling, the underline went away and everything worked fine.

I use #import "C:\Program\Delade filer\System\ado\msado15.dll" rename_namespace("USEADO"),rename("EOF","EndOfFile") in my header.

In cpp eg:

#include "stdafx.h"

int SQLsetInfo(THING *Thing, GADGET *Gadget)
{

HRESULT hr;                                                         
USEADO::_ConnectionPtr connection;                                  
USEADO::_RecordsetPtr recordset;                                    

 //Initialize COM  
    if(FAILED(hr = CoInitialize(NULL)))                         
    {   MessageBox( NULL, L"Initialize COM Failed", L"MyProg!",MB_ICONEXCLAMATION |MB_OK);
        //Do something, eg shut down DB stuff and continue without or exit program
        //Insert error handeler below
        return hr;//TODO Ad error handeling see line 149
    }   

if(FAILED(hr = connection.CreateInstance(__uuidof(USEADO::Connection))))
    {   MessageBox( NULL, L"Create connection instance Failed", L"MyProg!",MB_ICONEXCLAMATION |MB_OK);
        //Do something, eg shut down DB stuff and continue without or exit program
        return hr;
    }

if(FAILED(hr = recordset.CreateInstance(__uuidof(USEADO::Recordset))))
    {   MessageBox( NULL, L"Create recordset instance Failed", L"MyProg!",MB_ICONEXCLAMATION |MB_OK);
        //Do something, eg shut down DB stuff and continue without or exit program 
        return hr;
    }

    connection->CursorLocation = USEADO::adUseServer; //http://dev.mysql.com/tech-resources/articles/vb-cursors-and-locks.html                                           

    //Try to connect to SQL server
    try         { connection->Open(L"YOUR CONNECTION STRING", USEADO::adConnectUnspecified);    }
    catch(...)  {std::cout << "!!! connection->Open(ConnectionString   FAILED !!!" << std::endl;        }

I'm not an expert in C++, but this works fine for me. Hope it helps you to. If anyone else here has suggestions/critic to the above snippet I'm looking forward to it....