Ausführen eines Updategrams mit OLE DB (SQLXML 4.0)
Dieses Thema stellt ein funktionstüchtiges Beispiel bereit, um mit OLE DB ein Updategram auszuführen.
Verwenden von 'IcommandStream' zum Festlegen eines XML-Befehls
Die ICommandStream-Schnittstelle von OLE DB (Version 2.6 oder höher) übergibt einen Befehl als Datenstromobjekt statt als Zeichenfolge.
Dank dieser Schnittstelle kann ein Befehl in jeder beliebigen Codierung geschrieben sein, die der XML-Parser versteht. Wenn ICommand::Execute aufgerufen wird, wird der Befehlstext direkt aus dem Datenstrom gelesen, ohne dass eine Konvertierung erforderlich ist. XML-Befehle mit der ICommandStream-Schnittstelle auszuführen ist daher effizienter.
Festlegen von XML als Befehl mit 'IcommandStream' und Abrufen der Ergebnisse als XML-Dokument
Mit der ICommandStream-Schnittstelle können XML-Dokumente als Befehl festgelegt und die Ergebnisse als XML-Dokument abgerufen werden.
Ausführen von Vorlagen mit XPath-Abfragen
Die folgende XML-Vorlage, die aus einer XPath-Abfrage besteht, wird mit ICommandStream als Befehl angegeben:
<ROOT xmlns:sql="urn:schemas-microsoft-com:xml-sql">
<sql:xpath-query mapping-schema="Schema.xml">Person.Contact</sql:xpath-query>
</ROOT>
Die XPath-Abfrage in der Vorlage wird für das folgende Zuordnungsschema ausgeführt:
<?xml version="1.0" ?>
<Schema xmlns="urn:schemas-microsoft-com:xml-data" xmlns:dt="urn:schemas-microsoft-com:datatypes" xmlns:sql="urn:schemas-microsoft-com:xml-sql">
<ElementType name="Person.Contact" >
<AttributeType name="ContactID" />
<AttributeType name="FirstName" />
<AttributeType name="LastName" />
<attribute type="ContactID" />
<attribute type="FirstName" />
<attribute type="LastName" />
</ElementType>
</Schema>
Die Abfrage gibt alle Mitarbeiterelemente zurück. Mit der Standardzuordnung wird das <Person.Contact>-Element der Person.Contact-Tabelle in der AdventureWorks-Datenbank zugeordnet.
So legen Sie XML als Befehl fest und rufen das Ergebnis als XML-Dokument ab
Initialisieren Sie die Datenbank, und stellen Sie eine Verbindung zur Datenbank her.
Rufen Sie die ICommandStream-Schnittstelle für ICommand ab.
Legen Sie die erforderlichen Eigenschaften für den Befehl fest. In diesem Beispiel wird die anbieterspezifische Eigenschaft SSPROP_STREAM_BASEPATH auf das Verzeichnis festgelegt, in dem das Zuordnungsschema und die Vorlagendateien gespeichert sind.
Geben Sie mit ICommandStream::SetCommandStream den Befehlsdatenstrom an. In diesem Beispiel wird die XML-Vorlage, die ausgeführt wird, aus einer Datei gelesen. Dies ist nützlich, wenn Sie große XML-Vorlagen ausführen möchten.
Führen Sie den XML-Befehl mit ICommand::Execute aus, indem Sie die ID der IID_ISequentialStream-Schnittstelle anfordern.
Verarbeiten Sie das Ergebnis. In diesem Beispiel wird das aus dem Datenstrom gelesene XML auf dem Bildschirm angezeigt.
void InitializeAndEstablishConnection(); void SetCommandProperties(); void ProcessResultSet(); #define UNICODE #define _UNICODE #define DBINITCONSTANTS #define INITGUID #include <stdio.h> #include <tchar.h> #include <stddef.h> #include <windows.h> #include <iostream.h> #include <oledb.h> #include <SQLOLEDB.h> class CSequentialStream : public ISequentialStream { private: ULONG m_cRef; // reference count HANDLE m_hFile; // handle to the file LPWSTR m_wszFileName; // the file name public: CSequentialStream( LPWSTR ); virtual ~CSequentialStream(); // IUnknown Methods STDMETHODIMP_(ULONG) AddRef(); STDMETHODIMP_(ULONG) Release(); STDMETHODIMP QueryInterface( REFIID, LPVOID* ); // ISequentialStream Methods STDMETHODIMP Read( /* [out] */ void __RPC_FAR*, /* [in] */ ULONG, /* [out] */ ULONG __RPC_FAR* ); STDMETHODIMP Write( /* [in] */ const void __RPC_FAR*, /* [in] */ ULONG, /* [out]*/ ULONG __RPC_FAR* ); }; IDBInitialize* pIDBInitialize = NULL; IDBProperties* pIDBProperties = NULL; IDBCreateSession* pIDBCreateSession = NULL; IDBCreateCommand* pIDBCreateCommand = NULL; ICommand* pICommand = NULL; ICommandStream* pICommandStream = NULL; ICommandProperties* pICommandProperties = NULL; IColumnsInfo* pIColumnsInfo = NULL; ISequentialStream* pIXMLOutput = NULL; DBCOLUMNINFO* pDBColumnInfo = NULL; IAccessor* pIAccessor = NULL; DBPROP InitProperties[4]; DBPROPSET rgInitPropSet[1]; ULONG i, j; HRESULT hr; LONG cNumRows = 0; ULONG lNumCols; WCHAR* pStringsBuffer; DBBINDING* pBindings; ULONG ConsumerBufColOffset = 0; HACCESSOR hAccessor; ULONG lNumRowsRetrieved; HROW hRows[10]; HROW* pRows = &hRows[0]; BYTE* pBuffer; CSequentialStream XMLInput( L"Query.xml" ); CSequentialStream::CSequentialStream ( LPWSTR wszFileName ) : m_cRef( 0 ), m_hFile( NULL ), m_wszFileName( NULL ) { // The constructor AddRefs. AddRef(); // Allocate memory for the file name. m_wszFileName = (LPWSTR) CoTaskMemAlloc( ( wcslen( wszFileName ) + 1 ) * 2 ); // Copy the file name. wcscpy( m_wszFileName, wszFileName ); } CSequentialStream::~CSequentialStream ( ) { // Free any allocated memory. if( m_wszFileName ) CoTaskMemFree( m_wszFileName ); // Close the file. if( m_hFile ) CloseHandle( m_hFile ); } ULONG CSequentialStream::AddRef ( ) { return ++m_cRef; } ULONG CSequentialStream::Release() { if(--m_cRef) return m_cRef; delete this; return 0; } HRESULT CSequentialStream::QueryInterface ( REFIID riid, void** ppv ) { *ppv = NULL; if (riid == IID_IUnknown) *ppv = this; if (riid == IID_ISequentialStream) *ppv = this; if(*ppv) { ((IUnknown*)*ppv)->AddRef(); return S_OK; } return E_NOINTERFACE; } HRESULT CSequentialStream::Read ( void *pv, ULONG cb, ULONG* pcbRead ) { ULONG cBytesRead = 0; // Parameter checking. if(pcbRead) *pcbRead = 0; if(!pv) return STG_E_INVALIDPOINTER; if(cb == 0) return S_OK; // Do we need to open the file? if( m_hFile == NULL ) { // Open the file. m_hFile = CreateFile( m_wszFileName, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL ); // If the file failed to open, return E_FAIL. if( m_hFile == INVALID_HANDLE_VALUE ) return E_FAIL; } // Clear the buffer. ZeroMemory( pv, cb ); // Read cb bytes from the stream. if( !ReadFile( m_hFile, pv, cb, &cBytesRead, NULL ) ) return E_FAIL; // Inform the user of how many bytes to read. if( NULL != pcbRead ) *pcbRead = cBytesRead; if(cb != cBytesRead) return S_FALSE; return S_OK; } HRESULT CSequentialStream::Write ( const void *pv, ULONG cb, ULONG* pcbWritten ) { // For this example, only a read-only stream is needed. return STG_E_CANTSAVE; } void main() { // Call a function to initialize and establish a connection. InitializeAndEstablishConnection(); // Create a session object. if(FAILED(pIDBInitialize->QueryInterface( IID_IDBCreateSession, (void**) &pIDBCreateSession))) { cout << "Failed to obtain IDBCreateSession interface.\n"; } if(FAILED(pIDBCreateSession->CreateSession( NULL, IID_IDBCreateCommand, (IUnknown**) &pIDBCreateCommand))) { cout << "pIDBCreateSession->CreateSession failed.\n"; } // Access the ICommand interface. if(FAILED(pIDBCreateCommand->CreateCommand( NULL, IID_ICommand, (IUnknown**) &pICommand))) { cout << "Failed to access ICommand interface.\n"; } // Get an ICommandStream interface. if(FAILED(pICommand->QueryInterface( IID_ICommandStream, (void**) &pICommandStream))) { cout << "Failed to get an ICommandStream interface.\n"; } // Get an ICommandProperties interface. if(FAILED(pICommand->QueryInterface( IID_ICommandProperties, (void**) &pICommandProperties))) { cout << "Failed to get an ICommandProperties interface.\n"; } // Set the command properties. SetCommandProperties(); // Use SetCommandStream() to specify the command stream. if(FAILED(pICommandStream->SetCommandStream(IID_ISequentialStream, DBGUID_DEFAULT, (ISequentialStream*) &XMLInput ))) { cout << "Failed to set command stream.\n"; } // Execute the command. if(FAILED(hr = pICommand->Execute(NULL, IID_ISequentialStream, NULL, &cNumRows, (IUnknown **) &pIXMLOutput ))) { cout << "Failed to execute command.\n"; } // Process the result set. ProcessResultSet(); // Free memory. if( pIXMLOutput ) pIXMLOutput->Release(); pICommandProperties->Release(); pICommandStream->Release(); pICommand->Release(); pIDBCreateCommand->Release(); pIDBCreateSession->Release(); if(FAILED(pIDBInitialize->Uninitialize())) { /*Uninitialize is not required, but it fails if an interface has not been released. This can be used for debugging. cout << "Problem uninitializing.\n"; */ } // endif. pIDBInitialize->Release(); // Release the COM library. CoUninitialize(); }; //-------------------------------------------------------------------- void InitializeAndEstablishConnection() { // Initialize the COM library. CoInitialize(NULL); // Obtain access to the SQLOLEDB Provider. hr = CoCreateInstance(CLSID_SQLOLEDB, NULL, CLSCTX_INPROC_SERVER, IID_IDBInitialize, (void **) &pIDBInitialize); if(FAILED(hr)) { printf("Failed to get IDBInitialize interface.\n"); } // end if /* 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"Server"); 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"northwind"); InitProperties[1].dwOptions = DBPROPOPTIONS_REQUIRED; InitProperties[1].colid = DB_NULLID; // Username (login). InitProperties[2].dwPropertyID = DBPROP_AUTH_USERID; InitProperties[2].vValue.vt = VT_BSTR; InitProperties[2].vValue.bstrVal= SysAllocString(L"Login"); InitProperties[2].dwOptions = DBPROPOPTIONS_REQUIRED; InitProperties[2].colid = DB_NULLID; // Password. // InitProperties[3].dwPropertyID = DBPROP_AUTH_PASSWORD; // InitProperties[3].vValue.vt = VT_BSTR; // InitProperties[3].vValue.bstrVal= SysAllocString(L"Password"); // InitProperties[3].dwOptions = DBPROPOPTIONS_REQUIRED; // InitProperties[3].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].cProperties = 3; rgInitPropSet[0].rgProperties = InitProperties; // Set initialization properties. hr = pIDBInitialize->QueryInterface(IID_IDBProperties, (void **)&pIDBProperties); if(FAILED(hr)) { cout << "Failed to get IDBProperties interface.\n"; } hr = pIDBProperties->SetProperties(1, rgInitPropSet); if(FAILED(hr)) { cout << "Failed to set initialization properties.\n"; } // end if pIDBProperties->Release(); // Establish the connection to the data source. if(FAILED(pIDBInitialize->Initialize())) { cout << "Problem establishing connection to the data source.\n"; } } // End of InitializeAndEstablishConnection. void SetCommandProperties() { // for(i = 0; i < 4; i++) VariantInit(&InitProperties[0].vValue); // Server name. InitProperties[0].dwPropertyID = SSPROP_STREAM_BASEPATH; InitProperties[0].vValue.vt = VT_BSTR; InitProperties[0].vValue.bstrVal= SysAllocString(L"C:\\MyDir"); InitProperties[0].dwOptions = DBPROPOPTIONS_REQUIRED; InitProperties[0].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_SQLSERVERSTREAM; rgInitPropSet[0].cProperties = 1; rgInitPropSet[0].rgProperties = InitProperties; // Set initialization properties. hr = pICommandProperties->SetProperties(1, rgInitPropSet); if(FAILED(hr)) { cout << "Failed to set command properties.\n"; } // end if } // End of InitializeAndEstablishConnection. //-------------------------------------------------------------------- // Retrieve and display data resulting from a query. void ProcessResultSet() { CHAR szBuf[1000]; ULONG ulNumRead; HRESULT hr; if( pIXMLOutput == NULL ) return; // Read from the stream. ZeroMemory( szBuf, 1000 ); while( ( hr = pIXMLOutput->Read( szBuf, 1000, &ulNumRead ) ) == S_OK ) { cout << szBuf; } } // Process resultset.
Übergeben von Parametern an Vorlagen
In diesem Beispiel wird gezeigt, wie Parameterwerte an XML-Befehle übergeben werden können. Diese XML-Vorlage wird als Befehl angegeben:
<ROOT xmlns:sql='urn:schemas-microsoft-com:xml-sql'>
<sql:header><sql:param name='Title'>Mr.</sql:param></sql:header>
<sql:query>SELECT TOP 20 * FROM Person.Contact
WHERE Title = @Title
FOR XML AUTO</sql:query>
</ROOT>
Die Vorlage schließt eine SQL-Abfrage ein. Die Abfrage erfordert einen Wert für den Parameter (@Title). Wenn kein Parameterwert übergeben wird, wird der Standardwert ("Mr.") verwendet.
Beim Übergeben von Parameterwerten an eine Vorlage müssen sowohl der Parametername als auch der Parameterwert angegeben werden.
Der Code lautet wie folgt:
#define UNICODE
#define _UNICODE
#define DBINITCONSTANTS
#define INITGUID
#include <stdio.h>
#include <tchar.h>
#include <stddef.h>
#include <windows.h>
#include <iostream.h>
#include "oledb.h"
#include "SQLOLEDB.h"
HRESULT InitializeAndEstablishConnection(IDBInitialize ** ppIDBInitialize);
HRESULT SetCommandProperties(ICommand * pICommand);
HRESULT ProcessResultSet(ISequentialStream * pStreamOutput);
//---------------------------------------------------------------------
// Structure Definition Section
//---------------------------------------------------------------------
struct COLUMNDATA
{
DBLENGTH dwLength; // The length of the data field
DBSTATUS dwStatus; // The status value
BYTE bData[1]; // The start of the data field
};
class CSequentialStream : public ISequentialStream
{
private:
ULONG m_cRef; // reference count
HANDLE m_hFile; // handle to the file
LPWSTR m_wszFileName; // the file name
public:
CSequentialStream( LPWSTR );
virtual ~CSequentialStream();
// IUnknown Methods
STDMETHODIMP_(ULONG) AddRef();
STDMETHODIMP_(ULONG) Release();
STDMETHODIMP QueryInterface( REFIID, LPVOID* );
// ISequentialStream Methods
STDMETHODIMP Read(
/* [out] */ void __RPC_FAR*,
/* [in] */ ULONG,
/* [out] */ ULONG __RPC_FAR* );
STDMETHODIMP Write(
/* [in] */ const void __RPC_FAR*,
/* [in] */ ULONG,
/* [out]*/ ULONG __RPC_FAR* );
};
CSequentialStream::CSequentialStream
(
LPWSTR wszFileName
)
:
m_cRef( 0 ),
m_hFile( NULL ),
m_wszFileName( NULL )
{
// The constructor AddRefs.
AddRef();
// Allocate memory for the file name.
m_wszFileName = (LPWSTR) CoTaskMemAlloc( ( wcslen( wszFileName ) + 1 ) * 2 );
// Copy the file name
wcscpy( m_wszFileName, wszFileName );
}
CSequentialStream::~CSequentialStream
(
)
{
// Free any allocated memory.
if( m_wszFileName )
CoTaskMemFree( m_wszFileName );
// Close the file.
if( m_hFile )
CloseHandle( m_hFile );
}
ULONG
CSequentialStream::AddRef
(
)
{
return ++m_cRef;
}
ULONG CSequentialStream::Release()
{
if(--m_cRef)
return m_cRef;
delete this;
return 0;
}
HRESULT CSequentialStream::QueryInterface
(
REFIID riid,
void** ppv
)
{
*ppv = NULL;
if (riid == IID_IUnknown)
*ppv = this;
if (riid == IID_ISequentialStream)
*ppv = this;
if(*ppv)
{
((IUnknown*)*ppv)->AddRef();
return S_OK;
}
return E_NOINTERFACE;
}
HRESULT CSequentialStream::Read
(
void *pv,
ULONG cb,
ULONG* pcbRead
)
{
ULONG cBytesRead = 0;
// Parameter checking.
if(pcbRead)
*pcbRead = 0;
if(!pv)
return STG_E_INVALIDPOINTER;
if(cb == 0)
return S_OK;
// Do we need to open the file?
if( m_hFile == NULL )
{
// Open the file.
m_hFile = CreateFile( m_wszFileName, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL );
// If we failed to open the file, return E_FAIL.
if( m_hFile == INVALID_HANDLE_VALUE )
return E_FAIL;
}
// Clear the buffer.
ZeroMemory( pv, cb );
// Read cb bytes from the stream.
if( !ReadFile( m_hFile, pv, cb, &cBytesRead, NULL ) )
return E_FAIL;
// Inform the user how many bytes were read.
if( NULL != pcbRead )
*pcbRead = cBytesRead;
if(cb != cBytesRead)
return S_FALSE;
return S_OK;
}
HRESULT CSequentialStream::Write
(
const void *pv,
ULONG cb,
ULONG* pcbWritten
)
{
// For purposes of this example, only a read-only stream is needed.
return STG_E_CANTSAVE;
}
void main()
{
HRESULT hr = S_OK;
IDBInitialize * pIDBInitialize = NULL;
IDBCreateSession * pIDBCreateSession = NULL;
IDBCreateCommand * pIDBCreateCommand = NULL;
ICommand * pICommand = NULL;
ICommandStream * pICommandStream = NULL;
ICommandWithParameters* pICommandWithParameters = NULL;
ICommandText * pICommandText = NULL;
IAccessor * pIAccessor = NULL;
const ULONG nParams = 1;
DBPARAMS * pParams = NULL;
DBPARAMS params;
DBBINDING acDBBinding[nParams];
DBBINDSTATUS acDBBindStatus[nParams];
DBORDINAL rgParamOrdinals[1];
DBPARAMBINDINFO rgParamBindInfo[1];
const WCHAR * wszParamName = L"@CategoryName";
const WCHAR * wszDataSourceType = L"DBTYPE_WCHAR";
BYTE sprocparams[1000];
COLUMNDATA * pCol = (COLUMNDATA *) sprocparams;
ISequentialStream * pStreamOutput = NULL;
DBCOLUMNINFO * pDBColumnInfo = NULL;
HACCESSOR hAccessor;
CSequentialStream XMLInput( L"TemplateFile.xml" );
typedef struct tagSPROCPARAMS
{
WCHAR CategoryName[25];
} SPROCPARAMS;
CoInitialize(0);
// Call a function to initialize and establish connection.
if (FAILED(hr = InitializeAndEstablishConnection(&pIDBInitialize)))
goto Cleanup;
//Create a session object.
if(FAILED(hr = pIDBInitialize->QueryInterface(
IID_IDBCreateSession,
(void**) &pIDBCreateSession)))
{
cout << "Failed to obtain IDBCreateSession interface.\n";
goto Cleanup;
}
if(FAILED(hr = pIDBCreateSession->CreateSession(
NULL,
IID_IDBCreateCommand,
(IUnknown**) &pIDBCreateCommand)))
{
cout << "pIDBCreateSession->CreateSession failed.\n";
goto Cleanup;
}
//Access the ICommand interface.
if(FAILED(hr = pIDBCreateCommand->CreateCommand(
NULL,
IID_ICommand,
(IUnknown**) &pICommand)))
{
cout << "Failed to access ICommand interface.\n";
goto Cleanup;
}
// Get an ICommandStream interface
if(FAILED(pICommand->QueryInterface( IID_ICommandStream, (void**) &pICommandStream)))
{
cout << "Failed to get an ICommandStream interface.\n";
goto Cleanup;
}
//Use SetCommandStream() to specify the command stream.
if(FAILED(hr = pICommandStream->SetCommandStream(IID_ISequentialStream, DBGUID_DEFAULT, (ISequentialStream*) &XMLInput )))
{
cout << "Failed to set command stream.\n";
goto Cleanup;
}
// Set the command properties.
if (FAILED(hr = SetCommandProperties(pICommand)))
goto Cleanup;
//***************************************
pCol->dwStatus = DBSTATUS_S_OK;
wcscpy( (LPWSTR) pCol->bData, L"Condiments" );
pCol->dwLength = wcslen( (LPWSTR) pCol->bData) * sizeof(WCHAR);
/*Describe the consumer buffer by filling in the array.
of DBBINDING structures. Each binding associates
a single parameter to the consumer's buffer.*/
acDBBinding[0].iOrdinal = 1;
acDBBinding[0].obLength = offsetof( COLUMNDATA, dwLength );
acDBBinding[0].obStatus = offsetof( COLUMNDATA, dwStatus );
acDBBinding[0].pTypeInfo = NULL;
acDBBinding[0].pObject = NULL;
acDBBinding[0].pBindExt = NULL;
acDBBinding[0].dwPart = DBPART_VALUE | DBPART_STATUS | DBPART_LENGTH;
acDBBinding[0].dwMemOwner = DBMEMOWNER_CLIENTOWNED;
acDBBinding[0].dwFlags = 0;
acDBBinding[0].bScale = 0;
acDBBinding[0].obValue = offsetof( COLUMNDATA, bData );
acDBBinding[0].eParamIO = DBPARAMIO_INPUT;
acDBBinding[0].cbMaxLen = 50;
acDBBinding[0].wType = DBTYPE_WSTR;
acDBBinding[0].bPrecision = 0;
rgParamOrdinals[0] = 1;
rgParamBindInfo[0].bPrecision = 0;
rgParamBindInfo[0].bScale = 0;
rgParamBindInfo[0].dwFlags = DBPARAMFLAGS_ISINPUT;
rgParamBindInfo[0].pwszDataSourceType = (WCHAR *)wszDataSourceType;
rgParamBindInfo[0].pwszName = (WCHAR *)wszParamName;
rgParamBindInfo[0].ulParamSize = 35;
if (FAILED(hr = pICommandStream->QueryInterface(
IID_ICommandWithParameters,
(LPVOID *)&pICommandWithParameters)))
{
cout << "Error.\n";
goto Cleanup;
}
if (FAILED(hr = pICommandWithParameters->SetParameterInfo(
nParams,
rgParamOrdinals,
rgParamBindInfo)))
{
cout << "Error.\n";
goto Cleanup;
}
//Create an accessor from the above set of bindings.
if (FAILED(hr = pICommandStream->QueryInterface(
IID_IAccessor,
(void**)&pIAccessor)))
{
cout << "Failed to get IAccessor interface.\n";
goto Cleanup;
}
if (FAILED(hr = pIAccessor->CreateAccessor(
DBACCESSOR_PARAMETERDATA,
nParams,
acDBBinding,
sizeof(SPROCPARAMS),
&hAccessor,
acDBBindStatus)))
{
cout << "Failed to create accessor for the defined parameters.\n";
goto Cleanup;
}
/*
Fill in DBPARAMS structure for the command execution. This structure
specifies the parameter values in the command and is then passed
to Execute.
*/
params.pData = sprocparams; //pCol->bData; //sprocparams;
params.cParamSets = 1;
params.hAccessor = hAccessor;
pParams = ¶ms;
//***************************************
//Execute the command.
if(FAILED(hr = pICommand->Execute(NULL,
IID_ISequentialStream,
pParams,
NULL,
(IUnknown **) &pStreamOutput )))
{
cout << "Failed to execute command.\n";
goto Cleanup;
}
//Process the result set.
if (FAILED(hr = ProcessResultSet(pStreamOutput)))
{
goto Cleanup;
}
Cleanup:
//Free up memory.
if( pStreamOutput )
pStreamOutput->Release();
if (pICommandStream)
pICommandStream->Release();
if (pICommand)
pICommand->Release();
if (pIDBCreateCommand)
pIDBCreateCommand->Release();
if (pIDBCreateSession)
pIDBCreateSession->Release();
if (pIDBInitialize)
pIDBInitialize->Release();
if (hr)
{
IErrorInfo* pErrorInfo = NULL;
BSTR bstrDesc = NULL;
GetErrorInfo(0, &pErrorInfo);
if (pErrorInfo)
{
pErrorInfo->GetDescription(&bstrDesc);
printf ("\r\nError: %S\r\n", bstrDesc ? bstrDesc : L"Unknown error");
SysFreeString(bstrDesc);
pErrorInfo->Release();
}
}
//Release the COM library.
CoUninitialize();
};
//--------------------------------------------------------------------
HRESULT InitializeAndEstablishConnection(IDBInitialize ** ppIDBInitialize)
{
HRESULT hr = S_OK;
IDBInitialize * pIDBInitialize = NULL;
IDBProperties * pIDBProperties = NULL;
DBPROP rgIDBProps[4];
DBPROPSET rgIDBPropSet[1];
int ii;
if (!ppIDBInitialize)
return E_INVALIDARG;
*ppIDBInitialize = NULL;
/*
Initialize the property values needed
to establish the connection.
*/
for(ii = 0; ii < 4; ii++)
VariantInit(&rgIDBProps[ii].vValue);
//Obtain access to the SQLOLEDB provider.
if(FAILED(hr = CoCreateInstance(CLSID_SQLOLEDB,
NULL,
CLSCTX_INPROC_SERVER,
IID_IDBInitialize,
(void **) &pIDBInitialize)))
{
printf("Failed to get IDBInitialize interface.\n");
goto Cleanup;
}
//Server name.
rgIDBProps[0].dwPropertyID = DBPROP_INIT_DATASOURCE;
rgIDBProps[0].vValue.vt = VT_BSTR;
rgIDBProps[0].vValue.bstrVal= SysAllocString(L"server");
rgIDBProps[0].dwOptions = DBPROPOPTIONS_REQUIRED;
rgIDBProps[0].colid = DB_NULLID;
//Database.
rgIDBProps[1].dwPropertyID = DBPROP_INIT_CATALOG;
rgIDBProps[1].vValue.vt = VT_BSTR;
rgIDBProps[1].vValue.bstrVal= SysAllocString(L"Northwind");
rgIDBProps[1].dwOptions = DBPROPOPTIONS_REQUIRED;
rgIDBProps[1].colid = DB_NULLID;
//User name (login).
rgIDBProps[2].dwPropertyID = DBPROP_AUTH_USERID;
rgIDBProps[2].vValue.vt = VT_BSTR;
rgIDBProps[2].vValue.bstrVal= SysAllocString(L"sa");
rgIDBProps[2].dwOptions = DBPROPOPTIONS_REQUIRED;
rgIDBProps[2].colid = DB_NULLID;
//Password.
// rgIDBProps[3].dwPropertyID = DBPROP_AUTH_PASSWORD;
// rgIDBProps[3].vValue.vt = VT_BSTR;
// rgIDBProps[3].vValue.bstrVal= SysAllocString(L"password");
// rgIDBProps[3].dwOptions = DBPROPOPTIONS_REQUIRED;
// rgIDBProps[3].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 (rgIDBProps) to the SetProperties method.
*/
rgIDBPropSet[0].guidPropertySet = DBPROPSET_DBINIT;
// rgInitPropSet[0].cProperties = 4;
rgIDBPropSet[0].cProperties = 3;
rgIDBPropSet[0].rgProperties = rgIDBProps;
//Set initialization properties.
if (FAILED(hr = pIDBInitialize->QueryInterface(IID_IDBProperties,
(void **)&pIDBProperties)))
{
cout << "Failed to get IDBProperties interface.\n";
goto Cleanup;
}
if (FAILED(hr = pIDBProperties->SetProperties(1, rgIDBPropSet)))
{
cout << "Failed to set initialization properties.\n";
goto Cleanup;
} //end if
//Now establish the connection to the data source.
if(FAILED(hr = pIDBInitialize->Initialize()))
{
cout << "Problem in establishing connection to the data source.\n";
goto Cleanup;
}
*ppIDBInitialize = pIDBInitialize;
Cleanup:
for(ii = 0; ii < 4; ii++)
VariantClear(&rgIDBProps[ii].vValue);
if (pIDBProperties)
pIDBProperties->Release();
return hr;
} //End of InitializeAndEstablishConnection.
HRESULT SetCommandProperties(ICommand * pICommand)
{
HRESULT hr = S_OK;
DBPROP rgProps[1];
DBPROPSET rgPropSet[1];
ICommandProperties* pICommandProperties = NULL;
VariantInit(&rgProps[0].vValue);
//Server name.
rgProps[0].dwPropertyID = SSPROP_STREAM_BASEPATH;
rgProps[0].vValue.vt = VT_BSTR;
rgProps[0].vValue.bstrVal= SysAllocString(L"D:\\Test");
rgProps[0].dwOptions = DBPROPOPTIONS_REQUIRED;
rgProps[0].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 (rgProps) to the SetProperties method.
*/
rgPropSet[0].guidPropertySet = DBPROPSET_SQLSERVERSTREAM;
rgPropSet[0].cProperties = 1;
rgPropSet[0].rgProperties = rgProps;
// Get an ICommandProperties interface.
if(FAILED(pICommand->QueryInterface( IID_ICommandProperties, (void**) &pICommandProperties)))
{
cout << "Failed to get an ICommandProperties interface.\n";
goto Cleanup;
}
//Set initialization properties.
if(FAILED(hr = pICommandProperties->SetProperties(1, rgPropSet)))
{
cout << "Failed to set command properties.\n";
goto Cleanup;
}
Cleanup:
VariantClear(&rgProps[0].vValue);
if (pICommandProperties)
pICommandProperties->Release();
return hr;
}
//--------------------------------------------------------------------
//Retrieve and display data resulting from a query.
HRESULT ProcessResultSet(ISequentialStream * pStreamOutput)
{
CHAR szBuf[1000];
ULONG ulNumRead;
HRESULT hr;
if( pStreamOutput == NULL )
return E_INVALIDARG;
// Read from the stream
ZeroMemory( szBuf, 1000 );
while( ( hr = pStreamOutput->Read( szBuf, 1000, &ulNumRead ) ) == S_OK )
{
cout << szBuf;
cout.flush();
}
return hr;
} //ProcessResultSet.