Command and CommandText Properties Example (VC++)

The following code demonstrates how to use the Command property to update the text of a procedure.

// BeginCommandTextCpp
// This sample runs correctly only if procedure 'CustomerById'
// exists. If the procedure doesn't exist, please use 
// 'ADOXProceduresAppend.cpp' to creat it.

#import "c:\Program Files\Common Files\system\ado\msadox.dll"     no_namespace
#import "c:\Program Files\Common Files\system\ado\msado15.dll"

#include "iostream.h"
#include "stdio.h"
#include "conio.h"

//Function declarations
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);};
void ProcedureTextX(void);

//////////////////////////////////////////////////////////
//                                                      //
//      Main Function                                   //
//                                                      //
//////////////////////////////////////////////////////////
void main()
{
    if(FAILED(::CoInitialize(NULL)))
        return;

    ProcedureTextX();

    ::CoUninitialize();
}

//////////////////////////////////////////////////////////
//                                                      //
//       ProcedureTextX Function                        //
//                                                      //
//////////////////////////////////////////////////////////
void ProcedureTextX()
{
    HRESULT hr = S_OK;

    // Define ADOX object pointers.
    // Initialize pointers on define.
    // These are in the ADOX::  namespace.
    _CatalogPtr m_pCatalog = NULL;

    // Define ADODB object pointers.
    ADODB::_ConnectionPtr m_pCnn = NULL;
    ADODB::_CommandPtr m_pCommand = NULL;

    try
    {
        //Open the Connection
        TESTHR(hr = m_pCnn.CreateInstance(__uuidof(ADODB::Connection)));
        TESTHR(hr = m_pCatalog.CreateInstance(__uuidof(Catalog)));
        TESTHR(hr = m_pCommand.CreateInstance(__uuidof(ADODB::Command)));
        m_pCnn->Open("Provider='Microsoft.JET.OLEDB.4.0';"
            "data source='c:\\Program Files\\Microsoft Office"
            "\\Office\\Samples\\Northwind.mdb';","","",NULL);

        // Open the catalog
        m_pCatalog->PutActiveConnection(_variant_t((IDispatch *)m_pCnn));

        // Get the Command
        m_pCommand = m_pCatalog->Procedures->GetItem("CustomerById")->GetCommand();

        // Update the CommandText
        m_pCommand->PutCommandText("PARAMETERS [CustId] Text;select "
            "CustomerId, CompanyName, ContactName "
            "from Customers where CustomerId = [CustId]");
        printf("CommandText is updated.\n");

        // Update the Procedure
        m_pCatalog->Procedures->GetItem("CustomerById")->PutCommand(
            _variant_t((IDispatch *)m_pCommand));
        printf("Procedure 'CustomerById' is updated.\n");
    }
    catch(_com_error &e)
    {
        // Notify the user of errors if any.
        _bstr_t bstrSource(e.Source());
        _bstr_t bstrDescription(e.Description());

        printf("\n\tSource :  %s \n\tdescription : %s \n ",(LPCSTR)bstrSource,(LPCSTR)bstrDescription);
    }
    catch(...)
    {
        cout << "Error occured in ProcedureTextX...."<< endl;
    }
}
// EndCommandTextCpp

See Also

Command Property