Codice di esempio per l'uso di OLE DB per la ricerca in Active Directory
Nell'esempio di codice seguente viene illustrato come eseguire ricerche in Active Directory usando C++, COM e OLE DB. Questo è un esempio di una funzione che accetta il nome distinto del contenitore in cui eseguire la ricerca e le credenziali da usare per la ricerca. Nell'esempio verrà eseguita una ricerca di sottoalbero nel contenitore specificato per tutti gli oggetti con objectClass di "user". Nell'esempio verranno stampati gli attributi name e ADsPath di ogni utente nella finestra della console.
Esistono due dialetti di query che possono essere usati con il provider OLE DB ADSI, LDAP e SQL. Il dialetto viene specificato nel metodo ICommandText::SetCommandText con uno dei GUID seguenti:
- DBGUID_SQL per il dialetto SQL.
- DBGUID_LDAPDialect per il dialetto LDAP.
In questo esempio viene usato il dialetto LDAP.
Il metodo ICommandText::SetCommandText può accettare anche il GUID DBGUID_DEFAULT per il dialetto. In questo caso, ADSI tenterà prima di tutto di usare il dialetto SQL; in caso di errore, ADSI tenterà di usare il dialetto LDAP. Per altre informazioni, vedere Dialetto LDAP e dialetto SQL.
Per altre informazioni su OLE DB, vedere la Guida per programmatori OLE DB.
//********************************************************************
// #include statements
//********************************************************************
#include <atlbase.h>
#include <oledb.h>
#include <adsiid.h>
#include <oledberr.h>
//********************************************************************
// function prototypes
//********************************************************************
void PrintRowData(DBBINDING *rgBind,
DBCOLUMNINFO *pDBColumnInfo,
ULONG ulNumColsBind,
BYTE *pData);
//********************************************************************
// global variables and definitions
//********************************************************************
typedef struct
{
DBLENGTH dwLength;
DBSTATUS dwStatus;
BYTE bData[1];
}DBCOLUMNDATA, *PDBCOLUMNDATA;
#define NUMROWS_CHUNK 500
/*********************************************************************
PrintAllUsers()
*********************************************************************/
HRESULT PrintAllUsers(LPCWSTR pwszDN,
LPCWSTR pwszUsername,
LPCWSTR pwszPassword)
{
HRESULT hr;
DBCOLUMNINFO *rgDBColumnInfo = NULL;
LPWSTR pStringsBuffer = NULL;
DBBINDING *rgBind = NULL;
CComPtr<IDBInitialize> spDBInitialize;
CComPtr<IDBProperties> spDBProperties;
DBPROP InitProperties[3];
CComBSTR sbstrUsername;
CComBSTR sbstrPassword;
DBPROPSET InitPropSet;
CComPtr<IDBCreateSession> spCreateSession;
CComPtr<IDBCreateCommand> spCreateCommand;
CComPtr<ICommandText> spCommandText;
CComBSTR sbstrCommand;
CComPtr<IRowset> spRowset;
DBROWCOUNT cRows;
CComPtr<IColumnsInfo> spColumnsInfo;
DBORDINAL cColumns;
DWORD dwOffset;
DWORD cMaxRowSize;
HACCESSOR hAccessor;
BYTE *pRowData = NULL;
ULONG cRowsObtained;
CComPtr<IAccessor> spAccessor;
// Get a memory allocator for allocating and freeing memory.
CComPtr<IMalloc> spMalloc;
hr = CoGetMalloc(1, &spMalloc);
if(S_OK != hr)
{
return hr;
}
// Create an instance of the OLE DB - ODBC provider.
hr = CoCreateInstance(CLSID_ADsDSOObject,
NULL,
CLSCTX_INPROC_SERVER,
IID_IDBInitialize,
(void**)&spDBInitialize);
if(S_OK != hr)
{
return hr;
}
// Get the IDBProperties interface.
hr = spDBInitialize->QueryInterface(IID_IDBProperties,
(void**)&spDBProperties);
if(S_OK != hr)
{
return hr;
}
// Initialize the OLE DB property initializer structures.
for(UINT i = 0; i < 3; i++ )
{
VariantInit(&InitProperties[i].vValue);
InitProperties[i].dwOptions = DBPROPOPTIONS_REQUIRED;
InitProperties[i].colid = DB_NULLID;
}
// Level of prompting performed for the connection process.
InitProperties[0].dwPropertyID = DBPROP_INIT_PROMPT;
InitProperties[0].vValue.vt = VT_I2;
InitProperties[0].vValue.iVal = DBPROMPT_NOPROMPT;
// Set the user ID.
sbstrUsername = pwszUsername;
InitProperties[1].dwPropertyID = DBPROP_AUTH_USERID;
InitProperties[1].vValue.vt = VT_BSTR;
InitProperties[1].vValue.bstrVal = sbstrUsername;
// Set the password.
sbstrPassword = pwszPassword;
InitProperties[2].dwPropertyID = DBPROP_AUTH_PASSWORD;
InitProperties[2].vValue.vt = VT_BSTR;
InitProperties[2].vValue.bstrVal = sbstrPassword;
// Set the InitProperties array into the property set.
InitPropSet.guidPropertySet = DBPROPSET_DBINIT;
InitPropSet.cProperties = 3;
InitPropSet.rgProperties = InitProperties;
// Set initialization properties.
hr = spDBProperties->SetProperties(1, &InitPropSet);
if(S_OK != hr)
{
return hr;
}
// Initialize the connection.
hr = spDBInitialize->Initialize();
if(S_OK != hr)
{
return hr;
}
// Get the IDBCreateSession interface.
hr = spDBInitialize->QueryInterface(IID_IDBCreateSession,
(void**)&spCreateSession);
if(S_OK != hr)
{
return hr;
}
// Create an IDBCreateCommand object.
hr = spCreateSession->CreateSession(NULL,
IID_IDBCreateCommand,
(IUnknown**)&spCreateCommand);
if(S_OK != hr)
{
return hr;
}
// Create an ICommandText Interface from
// the ICreateCommand Interface.
hr = spCreateCommand->CreateCommand(NULL,
IID_ICommandText,
(IUnknown**)&spCommandText);
if(S_OK != hr)
{
return hr;
}
// Build the command string.
sbstrCommand = "<LDAP://";
sbstrCommand += pwszDN;
sbstrCommand += ">;(objectClass=user);name,adspath;subtree";
/*
Before executing the query, pass the command text for
the query along with the dialect of the command text.
In this case, use the LDAP dialect. You can also pass
DBGUID_DBSQL, providing the query text is in that format.
*/
hr = spCommandText->SetCommandText(DBGUID_LDAPDialect,
sbstrCommand);
if(S_OK != hr)
{
return hr;
}
/*
Instruct the Active Directory OLE DB provider
to execute the statement. If successful, an
IRowset interface is returned.
*/
hr= spCommandText->Execute(NULL,
IID_IRowset,
NULL,
&cRows,
(IUnknown**)&spRowset);
if(DB_SEC_E_PERMISSIONDENIED == hr)
{
return hr;
}
if(S_OK != hr)
{
return hr;
}
// Retrieve the search results.
/*
An IRowset object is now available. Send a query
for the IColumnsInfo interface to obtain the column
data of the result set.
*/
hr = spRowset->QueryInterface(IID_IColumnsInfo,
(void**)&spColumnsInfo);
if(S_OK != hr)
{
return hr;
}
/*
Use the IColumnsInfo::GetColumnInfo method to get
the column data from the command object.
*/
hr = spColumnsInfo->GetColumnInfo(&cColumns,
&rgDBColumnInfo,
&pStringsBuffer);
if(S_OK != hr)
{
goto PrintAllUsers_cleanup;
}
/*
Create column bindings for the result set.
This code example instructs the IAccessor to return
column data as Unicode strings.
*/
rgBind = (DBBINDING*)spMalloc->Alloc(sizeof(DBBINDING) * cColumns);
if(!rgBind)
{
goto PrintAllUsers_cleanup;
}
dwOffset = 0;
for(ULONG ulBind = 0; ulBind < cColumns; ulBind++)
{
// Binding structure.
rgBind[ulBind].dwPart = DBPART_VALUE | DBPART_LENGTH | DBPART_STATUS;
rgBind[ulBind].eParamIO = DBPARAMIO_NOTPARAM;
rgBind[ulBind].iOrdinal = rgDBColumnInfo[ulBind].iOrdinal;
rgBind[ulBind].wType = DBTYPE_WSTR;
rgBind[ulBind].pTypeInfo = NULL;
rgBind[ulBind].obValue = dwOffset + offsetof(DBCOLUMNDATA, bData);
rgBind[ulBind].obLength = dwOffset + offsetof(DBCOLUMNDATA, dwLength);
rgBind[ulBind].obStatus = dwOffset + offsetof(DBCOLUMNDATA, dwStatus);
rgBind[ulBind].cbMaxLen = rgDBColumnInfo[ulBind].ulColumnSize;
rgBind[ulBind].pObject = NULL;
rgBind[ulBind].pBindExt = NULL;
rgBind[ulBind].dwFlags = 0;
rgBind[ulBind].dwMemOwner = DBMEMOWNER_CLIENTOWNED;
rgBind[ulBind].bPrecision = 0;
rgBind[ulBind].bScale = 0;
dwOffset += rgBind[ulBind].cbMaxLen + offsetof(DBCOLUMNDATA, bData);
}
cMaxRowSize = dwOffset;
// Get the IAccessor interface from the rowset.
hr = spRowset->QueryInterface(IID_IAccessor, (void**)&spAccessor);
if(S_OK != hr)
{
goto PrintAllUsers_cleanup;
}
/*
Call the IAccessor::CreateAccessor method, which returns an
array of accessor handles. This is an array of handles
to the rows in the result set.
*/
hr = spAccessor->CreateAccessor(DBACCESSOR_ROWDATA,
ulBind,
rgBind,
0,
&hAccessor,
NULL);
if(S_OK != hr)
{
goto PrintAllUsers_cleanup;
}
// Allocate a block of memory that will hold one
// row of the result set.
pRowData = (BYTE*)spMalloc->Alloc(cMaxRowSize);
if(!pRowData)
{
goto PrintAllUsers_cleanup;
}
// Process all the rows, one by one, NUMROWS_CHUNK rows at a time.
do
{
HROW *rgRowHandles = NULL;
cRowsObtained = 0;
/*
Call the IRowset::GetNextRows method to specify
the number of rows desired, pointers to the return row data,
and the number of rows returned.
*/
hr = spRowset->GetNextRows(
0,
0,
NUMROWS_CHUNK,
&cRowsObtained,
&rgRowHandles);
if(SUCCEEDED(hr) && (cRowsObtained > 0))
{
// Loop through the rows obtained,
// getting the data for each.
for(ULONG ulRow = 0; ulRow < cRowsObtained; ulRow++)
{
// Retrieve the row.
hr = spRowset->GetData(rgRowHandles[ulRow],
hAccessor,
pRowData);
// Print to screen.
PrintRowData(rgBind, rgDBColumnInfo, ulBind, pRowData);
}
// Release the row handles.
hr = spRowset->ReleaseRows(cRowsObtained, rgRowHandles, 0, 0, 0);
}
// Free the row handles.
if(rgRowHandles)
{
spMalloc->Free(rgRowHandles);
}
}while(cRowsObtained > 0);
PrintAllUsers_cleanup:
if(rgDBColumnInfo)
{
spMalloc->Free(rgDBColumnInfo);
}
if(pStringsBuffer)
{
spMalloc->Free(pStringsBuffer);
}
if(rgBind)
{
spMalloc->Free(rgBind);
}
if(pRowData)
{
spMalloc->Free(pRowData);
}
}
/********************************************************************
PrintRowData()
********************************************************************/
void PrintRowData(DBBINDING *rgBind,
DBCOLUMNINFO pDBColumnInfo[],
ULONG ulNumColsBind,
BYTE *pData)
{
ULONG ulCurrentCol;
DBCOLUMNDATA *pColumn;
// Print each column that is bound to.
for(ulCurrentCol = 0;
ulCurrentCol < ulNumColsBind;
ulCurrentCol++)
{
/*
Get a pointer to the column data. The obLength member of
the DBBINDING structure contains the offset, in bytes, to
the column data.
*/
pColumn = (DBCOLUMNDATA*)(pData +
rgBind[ulCurrentCol].obLength);
// Only print columns that have a column name.
if(pDBColumnInfo[ulCurrentCol].pwszName)
{
// Print the column name.
wprintf(pDBColumnInfo[ulCurrentCol].pwszName);
wprintf(L": ");
// Print the column data.
switch(pColumn->dwStatus)
{
case DBSTATUS_S_ISNULL:
wprintf(L"<NULL>");
break;
case DBSTATUS_S_OK:
case DBSTATUS_S_TRUNCATED:
if((LPWSTR)pColumn->bData)
{
wprintf((LPWSTR)pColumn->bData);
}
else
{
wprintf(L"<no data>");
}
break;
case DBSTATUS_E_CANTCONVERTVALUE:
wprintf(L"<cannot convert value>");
break;
default:
wprintf(L"<unknown>");
break;
}
wprintf(L"\n");
}
}
wprintf(L"\n");
}