--- title: "Item Property Example (VC++) | Microsoft Docs" ms.prod: sql ms.prod_service: connectivity ms.technology: connectivity ms.custom: "" ms.date: "01/19/2017" ms.reviewer: "" ms.topic: conceptual dev_langs: - "C++" helpviewer_keywords: - "Item property [ADO], VC++ example" ms.assetid: 05ae3f5a-a0c1-459d-aa7d-ed7f3b2ecd60 author: MightyPen ms.author: genemi --- # Item Property Example (VC++) This example demonstrates how the [Item](../../../ado/reference/ado-api/item-property-ado.md) property accesses members of a collection. The example opens the ***Authors*** table of the ***Pubs*** database with a parameterized command. The parameter in the command issued against the database is accessed from the [Command](../../../ado/reference/ado-api/command-object-ado.md) object's [Parameters](../../../ado/reference/ado-api/parameters-collection-ado.md) collection by index and name. Then the fields of the returned [Recordset](../../../ado/reference/ado-api/recordset-object-ado.md) are accessed from that object's [Fields](../../../ado/reference/ado-api/fields-collection-ado.md) collection by index and name. ``` // BeginItemCpp.cpp // compile with: /EHsc #import "msado15.dll" no_namespace rename("EOF", "EndOfFile") #include #include #include // Function declarations inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);}; void ItemX(); void PrintProviderError(_ConnectionPtr pConnection); void PrintComError(_com_error &e); int main() { if (FAILED(::CoInitialize(NULL))) return -1; ItemX(); ::CoUninitialize(); } void ItemX() { HRESULT hr = S_OK; // Define ADO object pointers. Initialize pointers on define. These are in the ADODB:: namespace. _ConnectionPtr pConnection = NULL; _RecordsetPtr pRst = NULL; _CommandPtr pCmd = NULL; _ParameterPtr pPrm = NULL; FieldPtr pFld = NULL; // Other Variables. _bstr_t strCnn("Provider='sqloledb'; Data Source='My_Data_Source'; Initial Catalog='pubs'; Integrated Security='SSPI';"); _variant_t Column[9]; _variant_t vIndex; try { // Open connection. TESTHR(pConnection.CreateInstance(__uuidof(Connection))); TESTHR(pRst.CreateInstance(__uuidof(Recordset))); TESTHR(pCmd.CreateInstance(__uuidof(Command))); // Set the array with the authors table field (column) names Column[0] = "au_id"; Column[1] = "au_lname"; Column[2] = "au_fname"; Column[3] = "phone"; Column[4] = "address"; Column[5] = "city"; Column[6] = "state"; Column[7] = "zip"; Column[8] = "contract"; _bstr_t strText("SELECT * FROM authors WHERE state = ?"); pCmd->CommandText = strText; pPrm = pCmd->CreateParameter("ItemXparm", adChar, adParamInput, 2, "CA"); pCmd->Parameters->Append(pPrm); pConnection->Open(strCnn, "", "", adConnectUnspecified); pCmd->ActiveConnection = pConnection; // Connection and CommandType are omitted because a Command object is provided. _variant_t Conn; Conn.vt = VT_ERROR; Conn.scode = DISP_E_PARAMNOTFOUND; pRst->Open((_variant_t((IDispatch *) pCmd)), Conn, adOpenStatic, adLockReadOnly, -1); printf("The Parameters collection accessed by index...\n"); vIndex = (short) 0; pPrm = pCmd->Parameters->GetItem(&vIndex); printf("Parameter name = '%s', value = '%s'\n", (LPCSTR)pPrm->Name, (LPSTR)(_bstr_t)pPrm->Value); printf("\nThe Parameters collection accessed by name...\n"); pPrm = pCmd->Parameters->Item["ItemXparm"]; printf("Parameter name = '%s', value = '%s'\n", (LPCSTR)pPrm->Name, (LPSTR)(_bstr_t)pPrm->Value); printf("\nThe Fields collection accessed by index...\n"); pRst->MoveFirst(); long limit = 0; limit = ((pRst->Fields->Count) - 1); int intLineCnt = 8; for (short iIndex = 0 ; iIndex <= limit ; iIndex++) { vIndex = iIndex; pFld = pRst->Fields->GetItem(&vIndex); printf("Field %d : Name = '%s', ", iIndex, (LPCSTR)pFld->GetName()); _variant_t FldVal = pFld->GetValue(); // Because Value is the default property of a Property object, the use // of the actual keyword here is optional. switch(FldVal.vt) { case (VT_BOOL): if (FldVal.boolVal) printf("Value = 'True'"); else printf("Value = 'False'"); printf("\n"); break; case (VT_BSTR): printf("Value = '%s'", (LPCSTR)(_bstr_t)FldVal.bstrVal); printf("\n"); break; case (VT_I4): printf("Value = '%s'",(LPCSTR)FldVal.iVal); printf("\n"); break; case (VT_EMPTY): printf("Value = '%s'",(LPCSTR)FldVal.lVal); printf("\n"); break; default: break; } } printf("\nThe Fields collection accessed by name...\n"); pRst->MoveFirst(); for (int iIndex = 0; iIndex <= 8 ; iIndex++) { intLineCnt++; pFld = pRst->Fields->GetItem(Column[iIndex]); printf("Field name = '%s', ", (LPCSTR)pFld->GetName()); _variant_t FldVal = pFld->GetValue(); // Because Value is the default property of a Property object, // the use of the actual keyword here is optional. switch(FldVal.vt) { case (VT_BOOL): if (FldVal.boolVal) printf("Value = 'True'"); else printf("Value = 'False'"); printf("\n"); break; case (VT_BSTR): printf("Value = '%s'", (LPCSTR)(_bstr_t)FldVal.bstrVal); printf("\n"); break; case (VT_I4): printf("Value = '%s'", (LPCSTR)FldVal.iVal); printf("\n"); break; case (VT_EMPTY): printf("Value = '%s'", (LPCSTR)FldVal.lVal); printf("\n"); break; default: break; } } } catch(_com_error &e) { // Notify the user of errors if any. // Pass a connection pointer accessed from the Recordset. PrintProviderError(pConnection); PrintComError(e); } // Clean up objects before exit. if (pRst) if (pRst->State == adStateOpen) pRst->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; if( (pConnection->Errors->Count) > 0) { long nCount = pConnection->Errors->Count; // Collection ranges from 0 to nCount -1. for (long i = 0 ; i < nCount ; i++) { pErr = pConnection->Errors->GetItem(i); printf("\t Error number: %x\t%s", pErr->Number, pErr->Description); } } } void PrintComError(_com_error &e) { _bstr_t bstrSource(e.Source()); _bstr_t bstrDescription(e.Description()); // Print Com errors. printf("Error\n"); printf("\tCode = %08lx\n", e.Error()); printf("\tCode meaning = %s\n", e.ErrorMessage()); printf("\tSource = %s\n", (LPCSTR) bstrSource); printf("\tDescription = %s\n", (LPCSTR) bstrDescription); } ``` ## See Also [Command Object (ADO)](../../../ado/reference/ado-api/command-object-ado.md) [Fields Collection (ADO)](../../../ado/reference/ado-api/fields-collection-ado.md) [Item Property (ADO)](../../../ado/reference/ado-api/item-property-ado.md) [Parameters Collection (ADO)](../../../ado/reference/ado-api/parameters-collection-ado.md) [Recordset Object (ADO)](../../../ado/reference/ado-api/recordset-object-ado.md)