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ActiveConnection, CommandText, CommandTimeout, CommandType, Size, and Direction Properties Example (VC++)

This example uses the ActiveConnection, CommandText, CommandTimeout, CommandType, Size, and Direction properties to execute a stored procedure.

// BeginActiveConnectionCpp.cpp
// compile with: /EHsc
#import "msado15.dll" no_namespace rename("EOF", "EndOfFile")

#define TESTHR(x) if FAILED(x) _com_issue_error(x)

#include <stdio.h>
#include <ole2.h>
#include "conio.h"
#include "icrsint.h"

// class extracts  fname,lastname
class CEmployeeRs : public CADORecordBinding {
   BEGIN_ADO_BINDING(CEmployeeRs)

   // Column au_id is the 1st field in the recordset   
   ADO_VARIABLE_LENGTH_ENTRY2(1, adVarChar, m_szau_id, sizeof(m_szau_id), 
                              lau_idStatus, TRUE)

   ADO_VARIABLE_LENGTH_ENTRY2(2, adVarChar, m_szau_lname, sizeof(m_szau_lname), 
                              lau_lnameStatus, TRUE)

   ADO_VARIABLE_LENGTH_ENTRY2(3, adVarChar, m_szau_fname, sizeof(m_szau_fname), 
                              lau_fnameStatus, TRUE)

   END_ADO_BINDING()

public:
   CHAR m_szau_id[20];
   ULONG lau_idStatus;
   CHAR m_szau_fname[40];
   ULONG lau_fnameStatus;
   CHAR m_szau_lname[40];
   ULONG lau_lnameStatus;
};

// Function declaration
void ActiveConnectionX();
void PrintProviderError(_ConnectionPtr pConnection);

int main() {
   if ( FAILED(::CoInitialize(NULL)) )
      return -1;

   ActiveConnectionX();
   ::CoUninitialize();
}

void ActiveConnectionX() {
   HRESULT hr = S_OK;  

   // Define ADO object pointers, initialize pointers on define. These are in the ADODB::  namespace.
   _ConnectionPtr pConnection = NULL;
   _CommandPtr pCmdByRoyalty = NULL;
   _RecordsetPtr pRstByRoyalty = NULL;
   _RecordsetPtr pRstAuthors = NULL;
   _ParameterPtr pPrmByRoyalty = NULL;

   // Define Other variables
   IADORecordBinding *picRs = NULL;   // Interface Pointer declared.(VC++ Extensions)  TCS(SPA)
   CEmployeeRs emprs;   // C++ class object  TCS(SPA)
   _bstr_t strAuthorId;
   int intRoyalty;
   VARIANT vtroyal;

   _bstr_t strCnn("Provider='sqloledb'; Data Source='My_Data_Source'; Initial Catalog='pubs'; Integrated Security='SSPI';");

   try {
      // Define a command object for a stored procedure. 
      TESTHR(pConnection.CreateInstance(__uuidof(Connection)));
      hr = pConnection->Open(strCnn, "", "", adConnectUnspecified);

      TESTHR(pCmdByRoyalty.CreateInstance(__uuidof(Command)));

      pCmdByRoyalty->ActiveConnection = pConnection;
      pCmdByRoyalty->CommandText = "byRoyalty";
      pCmdByRoyalty->CommandType = adCmdStoredProc;
      pCmdByRoyalty->CommandTimeout = 15;

      // Define stored procedure's input parameter. 
      printf("Enter Royalty :  ");
      scanf_s("%d",&intRoyalty);

      // Assign Integer value 
      vtroyal.vt = VT_I2;
      vtroyal.iVal = intRoyalty;

      TESTHR(pPrmByRoyalty.CreateInstance(__uuidof(Parameter)));
      pPrmByRoyalty->Type = adInteger;
      pPrmByRoyalty->Size = 3;
      pPrmByRoyalty->Direction = adParamInput;
      pPrmByRoyalty->Value = vtroyal;
      pCmdByRoyalty->Parameters->Append(pPrmByRoyalty);

      // Create a recordset by executing a command.
      pRstByRoyalty = pCmdByRoyalty->Execute(NULL,NULL,adCmdStoredProc); 

      // Open the authors table to get author names for display. 
      TESTHR(pRstAuthors.CreateInstance(__uuidof(Recordset)));
      hr = pRstAuthors->Open("authors", strCnn, adOpenForwardOnly, adLockReadOnly, adCmdTable);

      // Open an IADORecordBinding interface pointer which we'll use for Binding Recordset to a class
      TESTHR(pRstAuthors->QueryInterface(__uuidof(IADORecordBinding), (LPVOID*)&picRs));

      // Bind the Recordset to a C++ Class here
      TESTHR(picRs->BindToRecordset(&emprs));

      // Print current data in the recordset ,adding author names from author table. 
      printf("Authors With  %d  Percent Royalty", intRoyalty);

      while (!(pRstByRoyalty->EndOfFile)) {
         strAuthorId = pRstByRoyalty->Fields->Item["au_id"]->Value;
         pRstAuthors->Filter = "au_id = '" + strAuthorId + "'";

         printf("\n\t%s, %s %s",emprs.lau_idStatus == adFldOK ? emprs.m_szau_id : "<NULL>",\
            emprs.lau_fnameStatus == adFldOK ? emprs.m_szau_fname : "<NULL>",\
            emprs.lau_lnameStatus == adFldOK ? emprs.m_szau_lname : "<NULL>");

         pRstByRoyalty->MoveNext(); 
      }

   }
   catch(_com_error &e) {
      // Notify the user of errors if any.
      _bstr_t bstrSource(e.Source());
      _bstr_t bstrDescription(e.Description());

      PrintProviderError(pConnection);
      printf("Source : %s \n Description : %s \n", (LPCSTR)bstrSource, (LPCSTR)bstrDescription);
   }


   // Clean up objects before exit. Release the IADORecordset Interface here
   if (picRs) 
      picRs->Release();

   if (pRstByRoyalty)
      if (pRstByRoyalty->State == adStateOpen)
         pRstByRoyalty->Close();
   if (pRstAuthors)
      if (pRstAuthors->State == adStateOpen)
         pRstAuthors->Close();
   if (pConnection)
      if (pConnection->State == adStateOpen)
         pConnection->Close();

}

void PrintProviderError(_ConnectionPtr pConnection) {
   // Print Provider Errors from Connection object.
   // pErr is a record object in the Connection's Error collection.
   ErrorPtr pErr = NULL;
   long nCount = 0;
   long i = 0;

   if ( (pConnection->Errors->Count) > 0) {
      nCount = pConnection->Errors->Count;
      // Collection ranges from 0 to nCount -1.
      for (i = 0 ; i < nCount ; i++) {
         pErr = pConnection->Errors->GetItem(i);
         printf("Error number: %x\t%s", pErr->Number, (LPCSTR)pErr->Description);
      }
   }
}

Input

25

Authors With  25  Percent Royalty
        724-80-9391, Stearns MacFeather
        899-46-2035, Anne Ringer
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