Re: Strings again :(

hamishd wrote:


I tried to modified your code and it seems to work (also in Unicode
builds)...
Here it is a compilable function GetExcelDriver(), that returns empty
string on error, or the required string on success:

<code>

// Gets the name of the Excel-ODBC driver.
// Returns empty string on error.
CString GetExcelDriver()
{
     TCHAR szBuf[64*1024];
     WORD cchBufMax = _countof(szBuf) - 1;
     WORD cchBufOut;
     TCHAR *pszBuf = szBuf;

     // Get the names of the installed drivers ("odbcinst.h" has to be
included )
     if(!SQLGetInstalledDrivers(szBuf,cchBufMax, &cchBufOut))
     {
         // Error
         return _T("");
     }

     // Search for the driver...
     do
     {
         if( _tcsstr( pszBuf, _T("Excel") ) != NULL )
         {
             // Found !
             return CString( pszBuf );
         }
         pszBuf = _tcschr( pszBuf, _T('\0') ) + 1;
     }
     while( pszBuf[1] != _T('\0') );

     // Not found - return empty string
     return _T("");
}

</code>

You can make it a static member function of your class, and call it like
this:

    ...
    m_sExcelDriver = GetExcelDriver();
    ...

However, reading the code you linked from CodeProject, it seems to me
that there are other problems in that code (that seems to be written for
ANSI-only builds, it seems to me not Unicode aware).

If you want to learn how to properly use CString class and write
Unicode-aware code, you may want to read this article by Joe on CodeProject:

http://www.codeproject.com/KB/string/cstringmgmt.aspx

(Probably you will find also similar articles on Joe's own site).

Giovanni