Reading from an Excel file (ODBC?)

Hello experts,

I am trying to add a "import from excel"-feature to my C++ application.
I thought it would be a simple task of traversing a couple of cells with an easy-to-use API.
However, as the project is built with standard C++ (no .net or mfc!) the only viable way seems to be using
the rather clumsy ODBC-approach. (I already tossed the idea of making this feature cross platform out the window)

I found this link on the subject:

Unforunately, that code is closely tied to MFC. Also it just pulls names like "demo_table" and "field_1"
out of thin air!

As I've managed to get something similar (Plain-C ODBC) working when reading data from an Access database,
Im supposing doing the same thing with an excel-sheet will be much of the same, except this time I don't
know the name of the sheets and fields.

Im looking for C/C++ code examples to read a couple of cells from a an Excel-sheet (Just reading, no writing).
I would appreciate if somebody could supply that, or provide a link to a website who does.
(Im not interested in having the user manually export the .xls file to a xml or comma-separated text file,
so you don't have to bother suggesting that, unless that can be made automatically without user interaction)

Who is Participating?
itsmeandnobodyelseConnect With a Mentor Commented:
>>> WinExec didn't work as it is can only used for .exe files

You might start cscript.exe rather than the vbs script itself.

>>>> How do i halt the progress of my c++ application until the script has finished executing?

You could poll until the .csv can be opened successfully

    ifstream csv;
    int count = 0;
    // wait for 5 seconds maximum
    while (++count < 50 &&
          Sleep(100);   // sleep 10 milliseconds
    if (!csv)
       return false;  // error

If you didn't want it stupid simple you might do that:

#include <string.h>
#include <windows.h>

#define MAX_LEN_CMDLINE                 512
#define DEF_ENV_BLOCK_NULL              NULL
#define DEF_CUR_DIR_NULL                NULL

int startVBS(const string& strVBS)
    char szCmdLine[MAX_LEN_CMDLINE] = "cscript ";
    strcat(szCmdLine, szArgs[n]);
    strcat(szCmdLine, strVBS.c_str());

    STARTUPINFO         si;
    memset(&si, 0, sizeof(STARTUPINFO));

    si.cb           = sizeof(STARTUPINFO);
    si.dwFlags      = STARTF_USESHOWWINDOW;
    si.wShowWindow  = SW_SHOWMINIMIZED;

    memset(&pi, 0, sizeof(PROCESS_INFORMATION));

    if (!CreateProcess(NULL,
        return GetLastError();

    // Wait until child process exits.
    WaitForSingleObject( pi.hProcess, INFINITE );

    // Close process and thread handles.
    CloseHandle( pi.hProcess );
    CloseHandle( pi.hThread );
    return 0;

2) The script pops up an annoying "Function XLS2CVS = FALSE/TRUE" messagebox

I don't know much of VB but I would comment the following line:

>>>> WScript.Echo "Function XLS2CSV() = " & XLS2CSV()

3) (vb-script) How do I pass parameters to the script?

Something like ...

' Display all command-line parameters
Set objArgs = Wscript.Arguments
For I = 0 to objArgs.Count - 1
          Wscript.Echo objArgs(I)

Regards, Alex

Here is the example I found on the web... It uses COM. I know you said no MFC or .Net... but maybe com is ok!

#import "C:\Program Files\Microsoft Office\Office\MSO9.DLL"
#import "C:\Program Files\Common Files\Microsoft Shared\VBA\VBA6\VBE6EXT.OLB"
#import "C:\Program Files\Microsoft Office\Office\EXCEL9.OLB" \
  rename("DialogBox", "ExcelDialogBox") \
  rename("RGB", "ExcelRGB") \

using namespace std;

int main()
  // Initialize COM
    Excel::_ApplicationPtr excel;
    // Initialize Excel and make sure it's initialized
    HRESULT hr = excel.CreateInstance(L"Excel.Application");
      char msg[1024] = {0};
      sprintf(msg, "E: There was an error initializing Excel: %d", hr);
      throw std::runtime_error(msg);
    Excel::_WorkbookPtr workbook = excel->Workbooks->Add(static_cast<long>(Excel::xlWorksheet)); // Create the workbook
    Excel::_WorksheetPtr worksheet = excel->ActiveSheet; // Get the active sheet

    worksheet->Open("whatever"); // Save it
    // This is how you put the values into the worksheet
    worksheet->Range["A1"]->Value = "Hello"; // Set a value
    workbook->Close(); // Close the workbook
    excel->Quit(); // Quit excel
  catch(_com_error &ce)
    // Handle the error

  return 0;

Hope this helps...
henrikatworkAuthor Commented:
Sorry, I've already seen that and its not really what im looking for.

Cloud Class® Course: Microsoft Exchange Server

The MCTS: Microsoft Exchange Server 2010 certification validates your skills in supporting the maintenance and administration of the Exchange servers in an enterprise environment. Learn everything you need to know with this course.

jkrConnect With a Mentor Commented:
What about running a free utility to do the job? See e.g.
BTW, with that one, you could even reconsider to make that feature cross-platform *g*
After you exported the contents to a .csv file by using the link jkr gave you, it is easy to read and parse the file like that:

#include <string>
#include <vector>
#include <fstream>
#include <sstream>
using namespace std;

struct Record
      string col1;
      int      col2;
      double col3;
      // ...
      enum { COL1, COL2, COL3, MAX_COLS };

bool getDataFromCsv(const string& csvfile, vector<Record>& arr)
       ifstream ifs(csvfile.c_str());
       if (!ifs) return false;
       string line;
       while (getline(ifs, line))
             // a .csv file separates each column entry by ;  (default)
             int pos = 0;
             int lpos = 0;
             int col = 0;
             line += ';';  // add a semicolon at end of line
             Record rec;
             while ((pos = line.find(';', lpos)) != string::npos)
                  string entry = line.substr(lpos, pos - lpos);
                     case COL1:
                            rec.col1 = entry;    
                     case COL2:
                            istringstream iss(entry);
                            iss >> rec.col2;
                            if (!iss)   // wrong integer
                               return false;
                     case COL3:
                            istringstream iss(entry);
                            iss >> rec.col3;
                            if (!iss)   // wrong double
                               return false;
                            return false;  // too many columns
       return true;


Regards, Alex
henrikatworkAuthor Commented:
Automatically export the file to cvs? I like the idea... but I can't have the external dependency of perl! (atleast not on windows) Especially not when the script depends on the following modules:
Spreadsheet::ParseExcel::FmtUnicode (should be included with Spreadsheet::ParseExcel)

I found this application:
But it costs money.

What would do is either something that (easily) compiled the perl script, or a similar utility written i C... Or back to the ODBC-approach.
>>>> Automatically export the file to cvs? I like the idea

You might use a vbscribt like the one that can be found at

You could do automation in C++ as well but it would be really hard work while it is relatively simple using VB.

Simply start the vbscript by

   WinExec("xls2csv.vbs", SW_HIDE);

Regards, Alex
henrikatworkAuthor Commented:
Hello Alex,

Your vb-script solution actually works! Well, not on my computer that didn't have excel installed... I suppose it uses the excel-odbc driver?

Anyway, common sense says that i should split the points between you and jkr (400/100 maybe?)
However as this is a 500pt questions I've decided to push my luck a little further...

1) WinExec didn't work as it is can only used for .exe files (?) I got it working with ShellExecute. So the question is: How do i halt the progress of my c++ application until the script has finished executing?

2) (More of a vb-script question) The script pops up an annoying "Function XLS2CVS = FALSE/TRUE" messagebox at the end, how do i get rid of it?

3) (vb-script) How do I pass parameters to the script? For instance the path to the .xls file and the .csv output file?

Actually none of these questions have anything to do with C++ (especially not 2 and 3, which I could ask in the vb-script forum)
>>>> #include <string.h>

replace that by

#include <string>
using namespace std;

I copied it from an older source which included old string header.

Regards, Alex

henrikatworkAuthor Commented:
Well deserved points... thanks Alex!
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.