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IRow::GetColumns(또는 IRow::Open) 및 ISequentialStream을 사용하여 열 가져오기

적용 대상: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW)

OLE DB 드라이버 다운로드

ISequentialStream 인터페이스를 사용하여 큰 데이터를 바인딩하거나 검색할 수 있습니다. 바인딩된 열의 경우 상태 플래그 DBSTATUS_S_TRUNCATED 데이터가 잘리고 있음을 나타냅니다.

Important

가능하면 Windows 인증을 사용하세요. Windows 인증을 사용할 수 없으면 런타임에 사용자에게 자격 증명을 입력하라는 메시지를 표시합니다. 자격 증명은 파일에 저장하지 않는 것이 좋습니다. 자격 증명을 유지하려면 Win32 crypto API를 사용하여 자격 증명을 암호화해야 합니다.

IRow::GetColumns(또는 IRow::Open) 및 ISequentialStream을 사용하여 열을 가져오려면

  1. 데이터 원본에 대한 연결을 설정합니다.

  2. 명령을 실행합니다(이 예제 에서는 IID_IRow 사용하여 ICommandExecute::Execute() 가 호출됨).

  3. IRow::Open() 또는 IRow::GetColumns()를 사용하여 열 데이터를 가져옵니다.

    • IRow::Open() 을 사용하여 행에서 ISequentialStream 을 열 수 있습니다. 열에 이진 데이터 스트림이 포함되어 있음을 나타내는 DBGUID_STREAM 지정합니다(IStream 또는 ISequentialStream 을 사용하여 열에서 데이터를 읽을 수 있습니다).

    • IRow::GetColumns()를 사용하는 경우 DBCOLUMNACCESS 구조의 pData 요소가 스트림 개체를 가리키도록 설정됩니다.

  4. ISequentialStream::Read()를 반복적으로 사용하여 지정된 바이트 수를 소비자 버퍼로 읽습니다.

예시

이 예제에서는 IRow를 사용하여 단일 행을 가져오는 방법을 보여줍니다. 이 예제에서는 행에서 한 번에 하나의 열을 검색합니다. 이 예제에서는 IRow::Open() 및 IRow::GetColumns()의 사용을 보여 줍니다. 이 예에서는 ISequentialStream::Read를 사용하여 열 데이터를 읽습니다.

이 문서의 Transact-SQL 코드 샘플은 AdventureWorks2022 또는 AdventureWorksDW2022 샘플 데이터베이스를 사용하며, 이는 Microsoft SQL Server 예시 및 커뮤니티 프로젝트(Microsoft SQL Server Samples and Community Projects) 홈 페이지에서 다운로드할 수 있습니다.

첫 번째(Transact-SQL) 코드 목록은 예제에서 사용하는 테이블을 만듭니다.

ole32.lib oleaut32.lib를 사용하여 컴파일하고 두 번째(C++) 코드 목록을 실행합니다. 이 애플리케이션은 컴퓨터의 기본 SQL Server 인스턴스에 연결됩니다. 일부 Windows 운영 체제에서는 (localhost) 또는 (local)을 해당 SQL Server 인스턴스의 이름으로 변경해야 합니다. 명명된 인스턴스에 연결하려면 연결 문자열을 L"(local)"에서 L"(local)\\name"으로 변경합니다. 여기서 name은 명명된 인스턴스입니다. 기본적으로 SQL Server Express는 명명된 인스턴스에 설치됩니다. INCLUDE 환경 변수에 msoledbsql.h가 들어 있는 디렉터리를 포함해야 합니다.

세 번째(Transact-SQL) 코드 목록은 예제에서 사용하는 테이블을 삭제합니다.

USE AdventureWorks2022;
GO  
  
IF EXISTS (SELECT name FROM sysobjects WHERE name = 'MyTable')  
     DROP TABLE MyTable  
GO  
  
CREATE TABLE MyTable  
(  
     col1  int,  
     col2  varchar(50),  
     col3  char(50),  
     col4  datetime,  
     col5  float,  
     col6  money,  
     col7  sql_variant,  
     col8  binary(50),  
     col9  text,  
     col10 image  
)  
GO  
  
-- Enter data  
INSERT INTO MyTable  
values  
(  
     10,  
     'abcdefghijklmnopqrstuvwxyz',  
     'ABCDEFGHIJKLMNOPQRSTUVWXYZ',  
     '11/1/1999 11:52 AM',  
     3.14,  
     99.95,  
     CONVERT(nchar(50), N'AbCdEfGhIjKlMnOpQrStUvWxYz'),  
     0x123456789,  
     REPLICATE('AAAAABBBBB', 500),  
     REPLICATE(0x123456789, 500)  
)  
GO  
// compile with: ole32.lib oleaut32.lib  
#define DBINITCONSTANTS  
#define INITGUID  
#define OLEDBVER 0x0250   // to include correct interfaces  
  
#include <stdio.h>  
#include <windows.h>  
#include <iostream>  
#include <oledb.h>  
#include <msoledbsql.h>  
  
using namespace std;  
  
const int kMaxBuff = 50;  
int InitializeAndEstablishConnection();  
HRESULT GetColumnSize(IRow* pUnkRow, ULONG iCol);  
ULONG PrintData(ULONG iCols, ULONG iStart, DBCOLUMNINFO* prgInfo, DBCOLUMNACCESS* prgColumns);  
HRESULT GetColumns(IRow* pUnkRow, ULONG iStart, ULONG iEnd);  
HRESULT GetSequentialColumn(IRow* pUnkRow, ULONG iCol, BOOL fOpen = TRUE);  
  
IDBInitialize*       pIDBInitialize     = NULL;  
IDBProperties*       pIDBProperties     = NULL;  
IDBCreateSession*    pIDBCreateSession  = NULL;  
IDBCreateCommand*    pIDBCreateCommand  = NULL;  
ICommandText*        pICommandText      = NULL;  
IRow*                pIRow              = NULL;  
DBCOLUMNINFO*        pDBColumnInfo      = NULL;  
IAccessor*           pIAccessor         = NULL;  
DBPROP               InitProperties[4];  
DBPROPSET            rgInitPropSet[1];  
ULONG                i, j;  
HRESULT              hresult;  
DBROWCOUNT           cNumRows = 0;  
ULONG                lNumCols;  
WCHAR*               pStringsBuffer;  
DBBINDING*           pBindings;  
ULONG                ConsumerBufColOffset = 0;  
HACCESSOR            hAccessor;  
ULONG                lNumRowsRetrieved;  
HROW                 hRows[10];  
HROW*                pRows = &hRows[0];  
  
int main() {  
   ULONG iidx = 0;  
   WCHAR* wCmdString = OLESTR("SELECT * FROM MyTable ");    
  
   // Call a function to initialize and establish connection.   
   if (InitializeAndEstablishConnection() == -1) {  
      cout << "Failed to initialize and establish connection.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   // Create a session object.  
   if (FAILED(pIDBInitialize->QueryInterface( IID_IDBCreateSession, (void**) &pIDBCreateSession))) {  
      cout << "Failed to obtain IDBCreateSession interface.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   if (FAILED(pIDBCreateSession->CreateSession( NULL,  
                                                IID_IDBCreateCommand,  
                                                (IUnknown**) &pIDBCreateCommand))) {  
      cout << "pIDBCreateSession->CreateSession failed.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   // Access the ICommandText interface.  
   if (FAILED(pIDBCreateCommand->CreateCommand( NULL, IID_ICommandText, (IUnknown**) &pICommandText))) {  
      cout << "Failed to access ICommand interface.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   // Use SetCommandText() to specify the command text.  
   if (FAILED(pICommandText->SetCommandText(DBGUID_DBSQL, wCmdString))) {  
      cout << "Failed to set command text.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   // Execute the command.  
   if (FAILED(hresult = pICommandText->Execute( NULL, IID_IRow, NULL, &cNumRows, (IUnknown **) &pIRow))) {  
      cout << "Failed to execute command.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   DBORDINAL cColumns = 0;  
   DBCOLUMNINFO* prgInfo = 0;  
   OLECHAR* pColNames;  
  
   // Get column count  
   HRESULT hr;  
   IColumnsInfo* pIColumnsInfo;  
   hr = pIRow->QueryInterface(IID_IColumnsInfo, (void**) &pIColumnsInfo);  
   if (FAILED(hr))  
      goto CLEANUP;  
  
   hr = pIColumnsInfo->GetColumnInfo(&cColumns, &prgInfo, &pColNames);  
   if (FAILED(hr))  
      goto CLEANUP;  
  
   // Get columns (one at a time) using ISequentialStream and Open  
   // 3rd parameter is by default TRUE indicating use of ISequentialStream and Open.  
   DBCOLUMNINFO* colInfo;   
   for ( iidx = 1 ; iidx <= cColumns ; iidx++ ) {  
  colInfo = (DBCOLUMNINFO*)(prgInfo + (iidx - 1));  
  if (colInfo->dwFlags & DBCOLUMNFLAGS_ISLONG)  
  hresult = GetSequentialColumn(pIRow, iidx);  
  else  
  hresult = GetColumns(pIRow, iidx, iidx);  
   }  
  
   // Release the Row object.  
   pIRow->Release();  
  
   // Execute the command again.  
   if (FAILED(hresult = pICommandText->Execute(NULL,  
                                               IID_IRow,  
                                               NULL,  
                                               &cNumRows,  
                                               (IUnknown **) &pIRow))) {  
      cout << "Failed to execute command.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   // Now get columns (one at a time) using ISequentialStream and GetColumns.   
   // The 3rd parameter is by default TRUE indicating use of ISequentialStream   
   // and GetColumns  
   for ( iidx = 1 ; iidx <= cColumns ; iidx++ ) {  
  colInfo = (DBCOLUMNINFO*)(prgInfo + (iidx - 1));  
  if (colInfo->dwFlags & DBCOLUMNFLAGS_ISLONG)  
  hresult = GetSequentialColumn(pIRow, iidx, FALSE);  
  else  
  hresult = GetColumns(pIRow, iidx, iidx);  
   }  
  
CLEANUP:  
   // Release memory.  
   pICommandText->Release();  
   pIDBCreateCommand->Release();  
   pIDBCreateSession->Release();  
  
   if (FAILED(pIDBInitialize->Uninitialize())) {  
      // Uninitialize not required, but it fails if an interface has not been released, can be used for debugging.   
      // cout << "Problem uninitializing.\n";  
   }  
  
   pIDBInitialize->Release();  
  
   CoTaskMemFree(prgInfo);  
   CoTaskMemFree(pColNames);  
   if( pIColumnsInfo )  
      pIColumnsInfo->Release();  
  
   // Release the COM library.  
   CoUninitialize();  
}  
  
HRESULT GetSequentialColumn(IRow* pUnkRow, ULONG iCol, BOOL fOpen) {  
   HRESULT hr = NOERROR;  
   ULONG cbRead = 0;  
   ULONG cbTotal = 0;  
   DBORDINAL cColumns = 0;  
   ULONG cReads = 0;  
   ISequentialStream* pIStream = NULL;  
   WCHAR* pBuffer[kMaxBuff];   // 50 chars read by ISequentialStream::Read()  
   DBCOLUMNINFO* prgInfo = 0;  
   OLECHAR* pColNames = 0;  
   IColumnsInfo* pIColumnsInfo;  
   DBID columnid;  
   DBCOLUMNACCESS column;  
  
   wprintf(L"[RETRIEVING COLUMN %d SEQUENTIALLY]\n", iCol);  
  
   // Get column information (basically get column id).  
   hr = pUnkRow->QueryInterface(IID_IColumnsInfo, (void**) &pIColumnsInfo);  
   if (FAILED(hr))  
      goto CLEANUP;  
  
   hr = pIColumnsInfo->GetColumnInfo(&cColumns, &prgInfo, &pColNames);  
   if (FAILED(hr))  
      goto CLEANUP;  
  
   // Get Column ID.  
   columnid = (prgInfo + (iCol - 1))->columnid;  
   if (fOpen) {   // Get columns using ISequentialStream and IRow::Open  
      wprintf(L"[RETRIEVING COLUMNS USING ");  
      wprintf(L" ISequentialSteam and Open]\n");  
  
      // Open sequential stream.  
      hr = pUnkRow->Open(NULL,  
                         &columnid,  
                         DBGUID_STREAM,  
                         0,  
                         IID_ISequentialStream,  
                         (LPUNKNOWN *)&pIStream);  
  
      if (FAILED(hr)) {  
         wprintf(L"Unable to get ISequentialStream interface.\n");  
         goto CLEANUP;  
      }  
   }  
  
   else {   // Get Columns using IRow::GetColumns and ISequentialStream.  
      wprintf(L"[RETRIEVING COLUMNS USING ");  
      wprintf(L" GetColumns and ISequentialStream]\n");  
  
  IUnknown* pUnkStream = NULL;  
  
      ZeroMemory(&column, sizeof(column));  
      column.columnid = prgInfo[iCol - 1].columnid;  
      column.wType = DBTYPE_IUNKNOWN;  
      column.pData = (LPVOID*) &pUnkStream;  
  
      hr = pUnkRow->GetColumns(1, &column);  
      if (FAILED(hr)) {  
         wprintf(L"Error executing IRow::GetColumns.\n");  
         goto CLEANUP;  
      }  
  
      hr = pUnkStream->QueryInterface(IID_ISequentialStream, (LPVOID*) &pIStream);  
      if (FAILED(hr)) {  
         wprintf(L"Unable to get ISequentialStream interface ");  
         wprintf(L"via IRow::GetColumns.\n");  
         goto CLEANUP;  
      }  
  
      pUnkStream->Release();  
   }  
  
   ZeroMemory(pBuffer, kMaxBuff * sizeof(WCHAR));  
  
   // Read 50 chars at a time until no more data.  
   do {  
      hr = pIStream->Read(pBuffer, kMaxBuff, &cbRead);  
      if (FAILED(hr)) {  
         wprintf(L"Error reading data.\n");  
         goto CLEANUP;  
      }  
  
      cbTotal = cbTotal + cbRead;  
  
      // Print the data  
      wprintf(L"READ #%d: %-*S\n", ++cReads, kMaxBuff, pBuffer);  
   } while(cbRead > 0);  
  
   wprintf(L"[READ %d bytes for column %d.\n", cbTotal, iCol);  
  
CLEANUP:  
   if (pIColumnsInfo)  
      pIColumnsInfo->Release();  
  
   CoTaskMemFree(prgInfo);  
   CoTaskMemFree(pColNames);  
  
   if (pIStream)  
      pIStream->Release();  
  
   return hr;  
}  
  
BOOL InitColumn(DBCOLUMNACCESS* pCol, DBCOLUMNINFO* pInfo) {  
   // If maximum possible length of a value column is very large (text or image  
   //  column is read) limit that size to 512 bytes (for illustration purposes).  
  
   ULONG ulSize;  
   if (pInfo->wType == DBTYPE_WSTR || pInfo->wType == DBTYPE_STR)  
      ulSize = (pInfo->ulColumnSize < 0x7fffffff) ? pInfo->ulColumnSize : 512;  
   else  
      ulSize = 128; //default buffer to handle conversion to text of non-string data types  
  
   // Verify data buffer is large enough.  
   if (pCol->cbMaxLen < (ulSize + 1)) {  
      if (pCol->pData) {  
         delete [] pCol->pData;  
         pCol->pData = NULL;  
      }  
  
      // Allocate data buffer  
      void * p = pCol->pData = new WCHAR[ulSize + 1];  
      if (!(p /*pCol->pData = new WCHAR[ulSize + 1]*/ ))  
         return FALSE;  
  
      // set the max length of caller-initialized memory.  
      pCol->cbMaxLen = sizeof(WCHAR) * (ulSize + 1);  
  
      // In the above 2 steps, pData is pointing to memory (it is not NULL) and   
      // cbMaxLen has a value (not 0), so next call to IRow->GetData()   
      // will read the data from the column.  
   }  
  
   // Clear memory buffer  
   ZeroMemory((void*) pCol->pData, pCol->cbMaxLen);  
  
   // Set properties.  
   //pCol->wType = DBTYPE_WSTR;  
   pCol->wType = DBTYPE_WSTR;  
   pCol->columnid = pInfo->columnid;  
   pCol->cbDataLen = 0;  
   pCol->dwStatus = 0;  
   pCol->dwReserved = 0;  
   pCol->bPrecision = 0;  
   pCol->bScale = 0;  
  
   return TRUE;  
}  
  
HRESULT GetColumns(IRow* pUnkRow, ULONG iStart, ULONG iEnd) {  
// Start and end are same. Thus, get only one column.  
   HRESULT          hr = E_FAIL;  
   ULONG            iidx;          // loop counter  
   DBORDINAL        cColumns;      // Count of columns  
   ULONG            cUserCols;     // Count of user columns  
   DBCOLUMNINFO*    prgInfo;       // Column of info. array  
   OLECHAR*         pColNames;     // Array of column names  
   DBCOLUMNACCESS*  prgColumns;    // Ptr to column access structures array  
   DBCOLUMNINFO*    pCurrInfo;  
   DBCOLUMNACCESS*  pCurrCol;  
  
   IColumnsInfo* pIColumnsInfo = NULL;  
  
   // Initialize  
   cColumns    = 0;  
   prgInfo     = NULL;  
   pColNames   = NULL;  
   prgColumns  = NULL;  
  
   printf("Retrieving data with GetColumns\n");  
  
   // Get column info to build column access array  
   hr = pUnkRow->QueryInterface(IID_IColumnsInfo, (void**)&pIColumnsInfo);  
  
   if (FAILED(hr))  
      goto CLEANUP;  
  
   hr = pIColumnsInfo->GetColumnInfo(&cColumns, &prgInfo, &pColNames);  
  
   if (FAILED(hr))  
      goto CLEANUP;  
  
   // Determine no. of columns to retrieve.  Since iEnd and iStart is same,   
   // this is redundent step.  cUserCols will always be 1.  
   cUserCols = iEnd - iStart + 1;   
  
   // Walk list of columns and setup a DBCOLUMNACCESS structure  
   DBCOLUMNACCESS * x = (prgColumns = new DBCOLUMNACCESS[cUserCols]);  
   if (!(x /*prgColumns = new DBCOLUMNACCESS[cUserCols]*/ )) {   // cUserCols is only 1  
      hr = E_FAIL;  
      goto CLEANUP;  
   }  
  
   ZeroMemory((void*) prgColumns, sizeof(DBCOLUMNACCESS) * cUserCols);  
  
   for ( iidx = 0 ; iidx < cUserCols ; iidx++ ) {  
      pCurrInfo = prgInfo + iidx + iStart - 1;  
      pCurrCol = prgColumns + iidx;  
  
      // Here the values of pData and cbMaxLen elements of DBCOLUMNACCESS   
      // elements is set. Thus IRow->GetColumns() will return actual data.  
      if ( InitColumn(pCurrCol, pCurrInfo) == FALSE )  
         goto CLEANUP;  
   }  
  
   hr = pUnkRow->GetColumns(cUserCols, prgColumns);   // cUserCols = 1  
   if (FAILED(hr))  
      printf("Error occurred\n");  
  
   // Show data.  
   PrintData(cUserCols, iStart, prgInfo, prgColumns);  
  
CLEANUP:  
   if (pIColumnsInfo)  
      pIColumnsInfo->Release();  
   if (prgColumns)  
      delete [] prgColumns;  
  
   return hr;  
}  
// This function returns the actual width of the data in the column (not the   
// columnwidth in DBCOLUMNFO structure which is the width of the column)  
HRESULT GetColumnSize(IRow* pUnkRow, ULONG iCol) {  
   HRESULT         hr = NOERROR;  
   DBORDINAL       cColumns = 0;   // Count the columns  
   DBCOLUMNINFO*   prgInfo;        // Column info array  
   OLECHAR*        pColNames;  
   DBCOLUMNACCESS  column;            
   DBCOLUMNINFO*   pCurrInfo;  
   IColumnsInfo*   pIColumnsInfo = NULL;  
  
   // Initialize  
   prgInfo = NULL;  
   pColNames = NULL;  
  
   printf("Checking column size\n");  
  
   // Get column info to build column access array  
   hr = pUnkRow->QueryInterface(IID_IColumnsInfo, (void**) &pIColumnsInfo);  
   if (FAILED(hr))  
      goto CLEANUP;  
  
   hr = pIColumnsInfo->GetColumnInfo(&cColumns, &prgInfo, &pColNames);  
   if (FAILED(hr))  
      goto CLEANUP;  
   printf("Value of cColumns is %d\n", cColumns);  
  
   // Setup a DBCOLUMNACCESS structure: pData is set to NULL and cbMaxLen is set   
   // to 0. Thus IRow->GetColumns() returns only the actual column length in  
   // cbDataLen member of DBCOLUMNACCESS structure.In this case you can call   
   // IRow->GetColumns() again for the same column to retrieve actual data in the second call.  
   ZeroMemory((void*) &column, sizeof(DBCOLUMNACCESS));  
   column.pData = NULL;  
  
   pCurrInfo = prgInfo + iCol - 1;  
   // Get column id in DBCOLUMNACCESS structure. It is then used in GetColumn().  
   column.columnid = pCurrInfo->columnid;   
  
   printf("column.columnid value is %d\n", column.columnid);  
   // We know which column to get.  The column.columnid gives the column number.  
   hr = pUnkRow->GetColumns(1, &column);   
   if (FAILED(hr))  
      printf("Errors occurred\n");  
  
   // Show data  
   PrintData(1, iCol, prgInfo, &column);  
  
CLEANUP:  
   if (pIColumnsInfo)  
      pIColumnsInfo->Release();  
   return hr;  
}  
  
BOOL GetStatus(DWORD dwStatus, WCHAR* pwszStatus) {  
   switch (dwStatus) {  
   case DBSTATUS_S_OK:  
      wcscpy_s(pwszStatus, 255, L"DBSTATUS_S_OK");  
      break;  
   case DBSTATUS_E_CANTCONVERTVALUE:  
   wcscpy_s(pwszStatus, 255, L"DBSTATUS_E_CANTCONVERTVALUE");  
   break;  
   case DBSTATUS_S_ISNULL:  
   wcscpy_s(pwszStatus, 255, L"DBSTATUS_S_ISNULL");  
   break;  
   case DBSTATUS_E_UNAVAILABLE:  
      wcscpy_s(pwszStatus, 255, L"DBSTATUS_E_UNAVAILABLE");  
      break;  
   case DBSTATUS_S_TRUNCATED:  
      wcscpy_s(pwszStatus, 255, L"DBSTATUS_S_TRUNCATED");  
      break;  
   default:  
      swprintf_s(pwszStatus, sizeof(pwszStatus), L"OTHER STATUS VALUE: %d", dwStatus);  
   }  
   return TRUE;  
}  
  
ULONG PrintData(ULONG iCols,   
                ULONG iStart,   
                DBCOLUMNINFO* prgInfo,   
                DBCOLUMNACCESS* prgColumns) {  
  
   WCHAR wszStatus[255];  
   DBCOLUMNINFO* pCurrInfo;  
   DBCOLUMNACCESS* pCurrCol;  
   ULONG iidx = 0;       // Loop counter  
  
   printf("%-3s %-20s %-21s %-9s %-9s %-50s\n", "No.", "Name", "Status", "Length", "Max", "Data");  
  
   for ( iidx = 0 ; iidx < iCols ; iidx++ ) {  
      pCurrInfo = prgInfo + iidx + iStart - 1;  
      pCurrCol = prgColumns + iidx;  
  
      GetStatus(pCurrCol->dwStatus, wszStatus);   
      // was the data successfully retrieved?  
      wprintf(L"%-3d %-20s %-21s %-9d %-9d %-50s\n", iStart + iidx,  
                                                    pCurrInfo->pwszName,  
                                                    wszStatus,  
                                                    pCurrCol->cbDataLen,  
                                                    pCurrCol->cbMaxLen,  
pCurrCol->dwStatus == DBSTATUS_S_ISNULL ? L"(NULL)" : (WCHAR*) pCurrCol->pData);  
   }  
  
   wprintf(L"\n");  
   return iidx;  
}  
  
int InitializeAndEstablishConnection() {      
   // Initialize the COM library.  
   CoInitialize(NULL);  
  
   // Obtain access to the MSOLEDBSQL provider.  
   hresult = CoCreateInstance(CLSID_MSOLEDBSQL,   
                              NULL,   
                              CLSCTX_INPROC_SERVER,  
                              IID_IDBInitialize,   
                              (void **) &pIDBInitialize);  
  
   if(FAILED(hresult)) {  
      printf("Failed to get IDBInitialize interface.\n");  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   // Initialize the property values needed to establish the connection.  
   for (i =  0 ; i < 4 ; i++ )  
      VariantInit(&InitProperties[i].vValue);  
  
   // Server name.  
   InitProperties[0].dwPropertyID = DBPROP_INIT_DATASOURCE;  
   InitProperties[0].vValue.vt = VT_BSTR;  
  
   InitProperties[0].vValue.bstrVal = SysAllocString(L"(local)");  
   InitProperties[0].dwOptions     = DBPROPOPTIONS_REQUIRED;  
   InitProperties[0].colid         = DB_NULLID;  
  
   // Database.  
   InitProperties[1].dwPropertyID  = DBPROP_INIT_CATALOG;  
   InitProperties[1].vValue.vt     = VT_BSTR;  
   InitProperties[1].vValue.bstrVal= SysAllocString(L"AdventureWorks");  
   InitProperties[1].dwOptions     = DBPROPOPTIONS_REQUIRED;  
   InitProperties[1].colid         = DB_NULLID;  
  
   // connection  
   InitProperties[2].dwPropertyID  = DBPROP_AUTH_INTEGRATED;  
   InitProperties[2].vValue.vt     = VT_BSTR;  
   InitProperties[2].vValue.bstrVal= SysAllocString(L"SSPI");  
   InitProperties[2].dwOptions     = DBPROPOPTIONS_REQUIRED;  
   InitProperties[2].colid         = DB_NULLID;  
  
   // Now that the properties are set, construct the DBPROPSET structure  
   // (rgInitPropSet). The DBPROPSET structure is used to pass an array   
   // of DBPROP structures (InitProperties) to the SetProperties method.  
   rgInitPropSet[0].guidPropertySet = DBPROPSET_DBINIT;  
   rgInitPropSet[0].cProperties    = 4;  
   rgInitPropSet[0].rgProperties   = InitProperties;  
  
   // Set initialization properties.  
   hresult = pIDBInitialize->QueryInterface(IID_IDBProperties, (void **)&pIDBProperties);  
   if (FAILED(hresult)) {  
      cout << "Failed to get IDBProperties interface.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   hresult = pIDBProperties->SetProperties(1, rgInitPropSet);   
   if (FAILED(hresult)) {  
      cout << "Failed to set initialization properties.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   pIDBProperties->Release();  
  
   // Now establish the connection to the data source.  
   if (FAILED(pIDBInitialize->Initialize())) {  
      cout << "Problem establishing connection to the data source.\n";  
      // Insert your code for cleanup and error handling  
      return -1;  
   }  
  
   return 0;  
}  
USE AdventureWorks2022;
GO  
  
IF EXISTS (SELECT name FROM sysobjects WHERE name = 'MyTable')  
     DROP TABLE MyTable  
GO  

참고 항목

OLE DB 방법 항목