Exemplo da propriedade Type (Field) (VC++)
Aplica-se ao: Access 2013, Office 2013
Este exemplo demonstra a propriedade Type exibindo o nome da constante que corresponde ao valor da propriedade Type de todos os objetos Field na tabela Funcionários . A função FieldType é necessária para a execução deste procedimento.
// BeginTypeFieldCpp
#import "c:\Program Files\Common Files\System\ADO\msado15.dll" no_namespace rename("EOF", "EndOfFile")
#include <ole2.h>
#include <stdio.h>
#include <conio.h>
// Function declarations
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);};
void TypeX(void);
_bstr_t FieldType(int intType);
void PrintProviderError(_ConnectionPtr pConnection);
void PrintComError(_com_error &e);
///////////////////////////////////////////////
// //
// Main Function //
// //
///////////////////////////////////////////////
void main()
{
if(FAILED(::CoInitialize(NULL)))
return;
TypeX();
::CoUninitialize();
}
///////////////////////////////////////////////
// //
// TypeX Function //
// //
///////////////////////////////////////////////
void TypeX(void)
{
HRESULT hr = S_OK;
// Define string variables.
_bstr_t strCnn("Provider='sqloledb';Data Source='MySqlServer';"
"Initial Catalog='pubs';Integrated Security='SSPI';");
// Define ADO object pointers.
// Initialize pointers on define.
// These are in the ADODB:: namespace.
_RecordsetPtr pRstEmployees = NULL;
FieldsPtr pFldLoop = NULL;
try
{
// Open recordset with data from Employee table.
TESTHR(pRstEmployees.CreateInstance(__uuidof(Recordset)));
pRstEmployees->Open ("employee",strCnn,
adOpenForwardOnly, adLockReadOnly, adCmdTable);
printf("Fields in Employee Table:\n\n");
// Enumerate the Fields collection of the Employees table.
pFldLoop = pRstEmployees->GetFields();
int intLine = 0;
for (int intFields = 0; intFields < (int)pFldLoop->
GetCount(); intFields++)
{
_variant_t Index;
Index.vt = VT_I2;
Index.iVal = intFields;
printf(" Name: %s\n" ,
(LPCSTR) pFldLoop->GetItem(Index)->GetName());
printf(" Type: %s\n\n",
(LPCTSTR)FieldType(pFldLoop->GetItem(Index)->Type));
intLine++;
if(intLine % 5 == 0)
{
printf("Press any key to continue...");
getch();
system("cls");
}
}
}
catch (_com_error &e)
{
// Notify the user of errors if any.
// Pass a connection pointer accessed from the Recordset.
_variant_t vtConnect = pRstEmployees->GetActiveConnection();
// GetActiveConnection returns connect string if connection
// is not open, else returns Connection object.
switch(vtConnect.vt)
{
case VT_BSTR:
PrintComError(e);
break;
case VT_DISPATCH:
PrintProviderError(vtConnect);
break;
default:
printf("Errors occured.");
break;
}
}
// Clean up objects before exit.
if (pRstEmployees)
if (pRstEmployees->State == adStateOpen)
pRstEmployees->Close();
}
///////////////////////////////////////////////
// //
// FieldType Function //
// //
///////////////////////////////////////////////
_bstr_t FieldType(int intType)
{
_bstr_t strType;
switch(intType)
{
case adChar:
strType = "adChar";
break;
case adVarChar:
strType = "adVarChar";
break;
case adSmallInt:
strType = "adSmallInt";
break;
case adUnsignedTinyInt:
strType = "adUnsignedTinyInt";
break;
case adDBTimeStamp:
strType = "adDBTimeStamp";
break;
default:
break;
}
return strType;
}
///////////////////////////////////////////////
// //
// PrintProviderError Function //
// //
///////////////////////////////////////////////
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("Error number: %x\t%s\n", pErr->Number,
(LPCSTR) pErr->Description);
}
}
}
///////////////////////////////////////////////
// //
// PrintComError Function //
// //
///////////////////////////////////////////////
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);
}
// EndTypeFieldCpp