--- title: "BOF, EOF, and Bookmark Properties 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: - "Bookmark property [ADO], VC++ example" - "EOF property [ADO], VC++ example" - "BOF property [ADO], VC++ example" ms.assetid: bd2b9d85-e75e-4fc8-a392-076582019caa author: MightyPen ms.author: genemi --- # BOF, EOF, and Bookmark Properties Example (VC++) The first function in this example uses the [BOF](../../../ado/reference/ado-api/bof-eof-properties-ado.md) and [EOF](../../../ado/reference/ado-api/bof-eof-properties-ado.md) properties to display a message if a user tries to move past the first or last record of a [Recordset](../../../ado/reference/ado-api/recordset-object-ado.md). It uses the [Bookmark](../../../ado/reference/ado-api/bookmark-property-ado.md) property to let the user flag a record in a **Recordset** and return to it later. The second function uses the Bookmark property to place the **Bookmark** of every other record from a **Recordset** into an array, and then filters the Recordset using the array. ## Example ``` // BOF_EOF_Bookmark.cpp // compile with: /EHsc #import "msado15.dll" no_namespace rename("EOF", "EndOfFile") #include #include #include "conio.h" #include "icrsint.h" // class extracts only author id,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 inline void TESTHR(HRESULT x) { if FAILED(x) _com_issue_error(x); }; void AppendX(); void PrintProviderError(_ConnectionPtr pConnection); int main() { HRESULT hr = S_OK; if (FAILED(::CoInitialize(NULL))) return -1; AppendX(); ::CoUninitialize(); } void AppendX() { HRESULT hr = S_OK; // Define ADO object pointers. Initialize pointers on define. These are in the ADODB:: namespace. _RecordsetPtr pRstByRoyalty = NULL; _RecordsetPtr pRstAuthors = NULL; _CommandPtr pcmdByRoyalty = NULL; _ParameterPtr pprmByRoyalty = NULL; _ConnectionPtr pConnection = NULL; //Define Other variables IADORecordBinding *picRs = NULL; // Interface Pointer declared.(VC++ Extensions) CEmployeeRs emprs; // C++ class object _bstr_t strCnn("Provider='sqloledb'; Data Source='My_Data_Source'; Initial Catalog='pubs'; Integrated Security='SSPI';"); _bstr_t strMessage, strAuthorID; int intRoyalty; VARIANT vtRoyalty; try { // Open a Connection. TESTHR(pConnection.CreateInstance(__uuidof(Connection))); hr = pConnection->Open(strCnn, "", "", adConnectUnspecified); pConnection->CursorLocation = adUseClient; // Open Command Object with one Parameter TESTHR(pcmdByRoyalty.CreateInstance(__uuidof(Command))); pcmdByRoyalty->CommandText = "byroyalty"; pcmdByRoyalty->CommandType = adCmdStoredProc; // Get parameter value and append parameter printf("Enter Royalty: "); scanf_s("%d", &intRoyalty); // Define Integer/variant. vtRoyalty.vt = VT_I2; vtRoyalty.iVal = intRoyalty; pprmByRoyalty = pcmdByRoyalty->CreateParameter("percentage", adInteger, adParamInput, sizeof(int), vtRoyalty); pcmdByRoyalty->Parameters->Append(pprmByRoyalty); pprmByRoyalty->Value = vtRoyalty; // Create Recordset by executing the command pcmdByRoyalty->ActiveConnection = pConnection; pRstByRoyalty = pcmdByRoyalty->Execute(NULL, NULL, adCmdStoredProc); // Open the authors table to get author names for display TESTHR(pRstAuthors.CreateInstance(__uuidof(Recordset))); // You have to explicitly pass the default Cursor type and LockType to the Recordset here hr = pRstAuthors->Open("authors", _variant_t((IDispatch*)pConnection, true), 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" "%s, %s %s",emprs.lau_idStatus == adFldOK ? emprs.m_szau_id : "",\ emprs.lau_fnameStatus == adFldOK ? emprs.m_szau_fname : "",\ emprs.lau_lnameStatus == adFldOK ? emprs.m_szau_lname : ""); pRstByRoyalty->MoveNext(); } } catch(_com_error &e) { _bstr_t bstrSource(e.Source()); _bstr_t bstrDescription(e.Description()); PrintProviderError(pConnection); printf("\n 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\n Error Description: %s\n", pErr->Number, (LPCSTR) pErr->Description); } } } ``` ## Input ``` 25 ``` ## Sample Output ``` Authors with 25 percent royalty 724-80-9391, Stearns MacFeather 899-46-2035, Anne Ringer ``` ## See Also [BOF, EOF Properties (ADO)](../../../ado/reference/ado-api/bof-eof-properties-ado.md) [Bookmark Property (ADO)](../../../ado/reference/ado-api/bookmark-property-ado.md) [Recordset Object (ADO)](../../../ado/reference/ado-api/recordset-object-ado.md)