Re: Not able to connect to the database - C / C++ / MFC Discussion Boards

Re: Loading Resource from dll fails

Super Hornet13-May-09 0:22

Super Hornet

13-May-09 0:22

Modified code according to your suggestion:

HINSTANCE hinstance = ::LoadLibrary("SampleEN.dll");

if (!hinstance)
{
    AfxMessageBox("Failed to load");
}
else
{
    HINSTANCE hInstResourceClient = AfxGetResourceHandle();

    // Use DLL's instance handle
    AfxSetResourceHandle(hinstance);

    LPCTSTR lpszName = MAKEINTRESOURCE(1); //IDC_STATIC_TOP has been defined as 1 in the dll
    HRSRC hrsrc = FindResource(hinstance, lpszName, RT_STRING);
    if (hrsrc)
    {
        HGLOBAL hglobal = LoadResource(hinstance, hrsrc);
        LockResource(hglobal);

        TCHAR szTemp[256];
        LoadString(hinstance, IDC_STATIC_TOP, szTemp, 255);
    }

    AfxSetResourceHandle(hInstResourceClient);
}

even now the string is empty. I get the error code: 1814 - which says resource couldn't be found. But I have re-verfied that the ID exists in the string table

Re: Loading Resource from dll fails

Super Hornet13-May-09 0:29

Super Hornet

13-May-09 0:29

I have tried commenting the statement
AfxSetResourceHandle(hinstance); but the same error

The error code 1814 comes after LaodString call

Re: Loading Resource from dll fails

Super Hornet13-May-09 1:21

Super Hornet

13-May-09 1:21

Now I am able to get the correct value's

The problem is with resource id's, I haven't defined same resource id in dll and in mfc application.

Re: Loading Resource from dll fails

Stuart Dootson13-May-09 0:10

Stuart Dootson

13-May-09 0:10

Super Hornet wrote:
m_hinstLib

What's that? Your resource DLL's handle is hinsttance ...

Re: Loading Resource from dll fails

Super Hornet13-May-09 0:23

Super Hornet

13-May-09 0:23

thank you for pointing the error

Not able to connect to the database

vital_parsley200012-May-09 23:34

vital_parsley2000

12-May-09 23:34

I m doing a database application.

in my OnNewDocument() i have the following code..

HRESULT hr;
try
{
AfxMessageBox("Inside try executed.",NULL,MB_OK); //Excecuted
hr = m_pConnection.CreateInstance(__uuidof(Connection));
AfxMessageBox("Created instance executed.",NULL,MB_OK);
if(SUCCEEDED(hr))
{
AfxMessageBox("If hr succeeded.",NULL,MB_OK);//Not Executed
hr = m_pConnection->Open(_bstr_t(L"Provider=sqloledb;Data Source=C:\\Program Files\\Microsoft SQL Server\\MSSQL\\Data\\LibDB.mdf;"),_bstr_t(L""),_bstr_t(L""),adModeUnknown);
if(SUCCEEDED(hr))
{
AfxMessageBox("Open connection executed.",NULL,MB_OK); //not executed
m_pConnection=TRUE;
}
}
AfxMessageBox("out",NULL,MB_OK);
}
catch(_com_error &e)
{
_bstr_t bstrSource(e.Source());
_bstr_t bstrDescription(e.Description());
TRACE( "Exception thrown for classes generated by #import" );
TRACE( "\tCode = %08lx\n", e.Error());
TRACE( "\tCode meaning = %s\n", e.ErrorMessage());
TRACE( "\tSource = %s\n", (LPCTSTR) bstrSource);
TRACE( "\tDescription = %s\n", (LPCTSTR) bstrDescription);
}
catch(...)
{
TRACE( "*** Unhandled Exception ***" );
}
return TRUE;
}

In the above code the if(SUCCEEDED(hr)) block is not executed.What could be the reason ?

Re: Not able to connect to the database

CPallini12-May-09 23:40

CPallini

12-May-09 23:40

An hint is given by the hr value.
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Re: Not able to connect to the database

Madhu Nair12-May-09 23:44

Madhu Nair

12-May-09 23:44

vital_parsley2000 wrote:
if(SUCCEEDED(hr)) block is not executed.What could be the reason ?

Get the hr value and pass it to FormatMessage function. You will get the cause.

To convert an HRESULT to DWORD you can use the following code snippet!

BOOL WIN32_FROM_HRESULT(HRESULT hr, OUT DWORD *pdwWin32)
{
 if ((hr & 0xFFFF0000) == MAKE_HRESULT(SEVERITY_ERROR, FACILITY_WIN32)) {
  // Could have come from many values, but we choose this one
  *pdwWin32 = HRESULT_CODE(hr);
  return TRUE;
 }
 if (hr == S_OK) {
  *pdwWin32 = HRESULT_CODE(hr);
  return TRUE;
 }
 // otherwise, we got an impossible value
 return FALSE;
}

I found this from here

Re: Not able to connect to the database

vital_parsley200013-May-09 4:19

vital_parsley2000

13-May-09 4:19

where do i insert this
code ?

Re: Not able to connect to the database

Madhu Nair13-May-09 19:45

Madhu Nair

13-May-09 19:45

vital_parsley2000 wrote:
where do i insert this code ?

In your source files, dear!

It is a function, you can either put it in your .cpp file or .h file in global scope or add as a member function in your class.

Am I missing something ?

Re: Not able to connect to the database [modified]

Madhu Nair13-May-09 20:03

Madhu Nair

13-May-09 20:03

Another Tip:

Put the variable hr in the debug watch window, append ", hr" (without the quotes) to it to have Visual C++ translate it for you!

Or you can use pseudo variable $err as $err,hr in Watch window.The $err pseudo variable provides the value, and the hr format specifier tells the watch window to format it as an error code.

http://i.msdn.microsoft.com/dd252945.fig05_L(en-us).gif[^]

modified on Thursday, May 14, 2009 2:21 AM

Re: Not able to connect to the database

David Crow13-May-09 3:17

David Crow

13-May-09 3:17

vital_parsley2000 wrote:
In the above code the if(SUCCEEDED(hr)) block is not executed.

Which one?

vital_parsley2000 wrote:
What could be the reason ?

CreateInstance() or Open() failed and control did not return to the subsequent if() statement.

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

Load data from database to BCG grid

MrKBA12-May-09 21:56

MrKBA

12-May-09 21:56

Hi,
I'm developing an application and i would display data from database(access, sqlserver, oracle) in a bcg grid.
So can someone help me by a simple example of code or how can i do for this.

Thank you very much. Smile | :)

Re: Load data from database to BCG grid

Madhu Nair12-May-09 22:14

Madhu Nair

12-May-09 22:14

khaliloenit wrote:
So can someone help me by a simple example of code

Using MS DataGrid control with ADO[^]

Also look at the DataGrid Control[^] MSDN

Re: Load data from database to BCG grid

MrKBA12-May-09 22:27

MrKBA

12-May-09 22:27

is this solution will work with SqlServer and Oracle database ?

Re: Load data from database to BCG grid

Rajesh R Subramanian12-May-09 22:32

Rajesh R Subramanian

12-May-09 22:32

khaliloenit wrote:
is this solution will work with SqlServer and Oracle database ?

Had you bothered to go through the links given to you, then you would have noticed the answer to your same exact question in the CP article:

"The sample has been tested with both MS Access and SQL Server, in theory you should be able to use it against all data sources that support OLE-DB."

It is a crappy thing, but it's life -^ Carlo Pallini

Re: Load data from database to BCG grid

MrKBA12-May-09 22:37

MrKBA

12-May-09 22:37

Sorry, but there is a solution with BCG Grid?

Re: Load data from database to BCG grid

MrKBA13-May-09 22:47

MrKBA

13-May-09 22:47

Please i try to use MS DataGrid in the Using MS DataGrid control with ADO[^] but i work with VS2003 and i don't find where i can add the Microsoft datagrid control with ADO !!!!?
So can you help me

Append BStr

Mogaambo12-May-09 21:23

Mogaambo

12-May-09 21:23

Below is the code to append Bstr, but in debug mode it gives error
' ::SysFreeString(dest); ' and in release mode if i dont write ' ::SysFreeString(dest); ' it corrupts heap. What optimization i do.

BSTR StringAppend(const BSTR dest,const BSTR src)
{
long destLen=::SysStringByteLen(dest);
long srcLen=::SysStringByteLen(src);

BSTR st3 = ::SysAllocStringByteLen(NULL,destLen+srcLen);
try
{
if(st3==NULL)
{
throw "Insufficient Memory";
}
else
{
wcscpy(st3, dest);
wcscat(st3, src);
::SysFreeString(dest);// here it gives error in debug mode
}
}
catch(char * error)
{
throw error;
}

return st3;
}

“You will never be a leader unless you first learn to follow and be led.”
–Tiorio

"Coming together is a beginning, staying together is progress, and working together is success." Henry Ford

Re: Append BStr

Madhu Nair12-May-09 21:27

Madhu Nair

12-May-09 21:27

A const BSTR dest ?
Why const ?

Re: Append BStr

CPallini12-May-09 21:31

CPallini

12-May-09 21:31

Why are you freeing dest?

Smile | :)

Re: Append BStr

Mogaambo12-May-09 22:26

Mogaambo

12-May-09 22:26

CPallini wrote:
Why are you freeing dest?

Because if i do not free, it gives error that heap is violated in release mode and when i traced down it goes in the NULL condition.

“You will never be a leader unless you first learn to follow and be led.”
–Tiorio

"Coming together is a beginning, staying together is progress, and working together is success." Henry Ford

Re: Append BStr

CPallini12-May-09 22:33

CPallini

12-May-09 22:33

Please show us the calling code.
Smile | :)

Re: Append BStr

Mogaambo12-May-09 22:36

Mogaambo

12-May-09 22:36

Here is my calling code. value variable is of type BSTR

BSTR GetNewRow()
{
value=GetLoggedInUser();

BSTR strComma=::SysAllocString(L",");
BSTR strNewLine=::SysAllocString(L"\n");

value=StringAppend(value,strComma);

value=StringAppend(value,strCategory);
value=StringAppend(value,strComma);
value=StringAppend(value,strItemName);
value=StringAppend(value,strComma);
value=StringAppend(value,strInstallDate);
value=StringAppend(value,strComma);
value=StringAppend(value,strVersion);
value=StringAppend(value,strComma);
value=StringAppend(value,strValue1);
value=StringAppend(value,strComma);
value=StringAppend(value,strValue2);
value=StringAppend(value,strComma);
value=StringAppend(value,strValue3);
value=StringAppend(value,strNewLine);

::SysFreeString(strComma);
::SysFreeString(strNewLine);

return value;
}

“You will never be a leader unless you first learn to follow and be led.”
–Tiorio

"Coming together is a beginning, staying together is progress, and working together is success." Henry Ford

Re: Append BStr

CPallini12-May-09 23:14

CPallini

12-May-09 23:14

It looks like the problem is in your bad mixing of char and wchar calls:
with the following line

BSTR st3 = ::SysAllocStringByteLen(NULL,destLen+srcLen);

you're allocating (destLen + srcLen + 1) bytes.

while in the following calls

wcscpy(st3, dest);
wcscat(st3, src);

you need, (destLen + srcLen + 2) bytes.

Smile | :)

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