Article
09/27/2010

Exécution d'un code de mise à jour (updategram) à l'aide d'OLE DB (SQLXML 4.0)

Cette rubrique fournit un exemple fonctionnel de l'utilisation d'OLE DB pour exécuter un code de mise à jour.

Utilisation d'ICommandStream pour définir une commande XML

L'interface ICommandStream d'OLE DB (version 2.6 ou ultérieure) passe une commande en tant qu'objet de flux, et non en tant que chaîne.

Cette interface permet à une commande d'être codée dans n'importe quel format pris en charge par l'analyseur XML. Lorsque ICommand::Execute est appelé, le texte de la commande est lu directement à partir du flux et aucune conversion n'est requise. Par conséquent, l'exécution de commandes XML à l'aide de l'interface ICommandStream est plus efficace.

Définition de code XML en tant que commande à l'aide d'ICommandStream et récupération les résultats sous forme d'un document XML

L'interface ICommandStream peut être utilisée pour définir des documents XML en tant que commande, et les résultats peuvent être récupérés sous forme d'un document XML.

Exécution de modèles avec des requêtes XPath

Le modèle XML suivant comprenant une requête XPath est spécifié en tant que commande à l'aide d'ICommandStream :

<ROOT xmlns:sql="urn:schemas-microsoft-com:xml-sql">
<sql:xpath-query mapping-schema="Schema.xml">Person.Contact</sql:xpath-query>
</ROOT>

La requête XPath dans le modèle est exécutée sur le schéma de mappage suivant :

<?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>

La requête retourne tous les éléments d'employé. Avec le mappage par défaut, l'élément <Person.Contact> est mappé à la table Person.Contact dans la base de données AdventureWorks.

Pour définir le code XML en tant que commande et récupérer les résultats sous forme d'un document XML

Initialisez et établissez une connexion à la base de données.
Obtenez l'interface ICommandStream sur ICommand.
Définissez les propriétés de commande nécessaires. Dans cet exemple, la propriété SSPROP_STREAM_BASEPATH spécifique au fournisseur a pour valeur le répertoire où le schéma de mappage et les fichiers modèles sont stockés.
Utilisez ICommandStream::SetCommandStream pour spécifier le flux de commandes. Dans cet exemple, le modèle XML qui est exécuté est lu à partir d'un fichier. Cela s'avère utile lorsque vous souhaitez exécuter de grands modèles XML.
Exécutez la commande XML à l'aide d' ICommand::Execute en demandant l'ID d'interface IID_ISequentialStream.

Traitez le résultat. Dans cet exemple, le code XML lu à partir du flux est affiché à l'écran.

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.

Transmission des paramètres aux modèles

Cet exemple montre comment les valeurs de paramètre peuvent être passées aux commandes XML. Ce modèle XML est spécifié en tant que commande :

<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>

Le modèle inclut une requête SQL. La requête requiert une valeur pour son paramètre (@Title). Si aucune valeur de paramètre n'est passée, la valeur par défaut ("Mr.") est utilisée.

Pour passer des valeurs de paramètre à un modèle, le nom et la valeur du paramètre doivent être spécifiés.

Voici le code :

#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 = &params;

    //***************************************
    //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.

Partager via