VC中的数据库存储二进制文件

/*

  测试插入流文件

*/

void insert_()

{

    _StreamPtr    pwStream;    

    _bstr_t        strPath("D:\\my\\21.wav");

    _bstr_t        strOpen("");

 

    _variant_t    varBLOB;

    _variant_t    varOptional(DISP_E_PARAMNOTFOUND,VT_ERROR); 

 

    HRESULT hr = pwStream.CreateInstance(_uuidof(Stream));        //创建流对象

    if(SUCCEEDED(hr))

    {

        pwStream->Type = adTypeBinary;

        hr = pwStream->Open(varOptional, adModeUnknown, adOpenStreamUnspecified, strOpen, strOpen);            //打开流

    }

 

    strSql = "select * from t_mov1 where 1 = 0";

    m_pRecordset->Open(strSql,  _variant_t((IDispatch*)m_pConnection,true),

                adOpenDynamic, adLockOptimistic, adCmdText);

    if(SUCCEEDED(hr))

    {

        pwStream->LoadFromFile(strPath);        //读取文件

        m_pRecordset->AddNew(vtMissing, vtMissing);

        m_pRecordset->PutCollect("id", (long)id);

        m_pRecordset->PutCollect("b_flow", pwStream->Read(adReadAll));    //将数据写入数据库

        m_pRecordset->Update();

        pwStream->Close();

    }

}

/*

    从数据库中读出流数据

*/

void read(int id)

{

    char    *m_pBuffer;

    _StreamPtr    prStream;

    _bstr_t        strOpen("");

    _variant_t  varOptional(DISP_E_PARAMNOTFOUND,VT_ERROR);

    HRESULT        hr;

 

    hr = prStream.CreateInstance(_uuidof(Stream));            //创建流

    if(SUCCEEDED(hr))

    {

        prStream->Type = adTypeBinary;

        hr = prStream->Open(varOptional, adModeUnknown, adOpenStreamUnspecified, strOpen, strOpen);        //打开流

    }

 

    CString strSql;

    strSql.Format("select * from t_mov1 where id = %d", id);

 

    m_pRecordset->Open((_bstr_t)strSql, _variant_t((IDispatch*)m_pConnection,true),

                adOpenDynamic, adLockOptimistic, adCmdText);

 

    if(SUCCEEDED(hr))

    {

        prStream->Write(m_pRecordset->Fields->GetItem("b_flow")->GetValue());

         

        long lDataSize;

        lDataSize = prStream->GetSize();    

 

        _variant_t  varBLOB;

         

        //流指针指向首位

        prStream->put_Position(0);

        //varBLOB.vt = VT_ARRAY | VT_UI1;

        //varBLOB.scode = DISP_E_PARAMNOTFOUND;

        varBLOB = prStream->Read(adReadAll);

             

        if(varBLOB.vt == (VT_ARRAY | VT_UI1))

        {    

            //分配必要的存储空间

            if(m_pBuffer = new char[lDataSize+1])                

            {    

                char *pBuf = NULL;

                 

                //复制数据到缓冲区m_pBuffer

                SafeArrayAccessData(varBLOB.parray,(void **)&pBuf);                

                memcpy(m_pBuffer, pBuf, lDataSize);            

                SafeArrayUnaccessData (varBLOB.parray);                

            }

        }

 

        prStream->SaveToFile("d:\\1.wav", adSaveCreateOverWrite);

        prStream->Close();

    }

}