急求ADO Field AppendChunk插入大字节数据的例子。

Question

简单管用就行，谢啦！

Answer 1

我的OLE数据是一个文件。我在file.read就出问题了。
CFile file;
file.Open(pathname,CFile::modeRead);
ULONG filelenth=file.GetLength();//读取文件长度 SAFEARRAYBOUND szbuffer[1];
SAFEARRAY FAR *psa;
_variant_t varChunk;
        szbuffer->lLbound =0;
szbuffer->cElements =filelenth;
file.Read(szbuffer,filelenth);
        file.Close();

Answer 2

BOOL xxxxxx::SaveData()
{
try
{
//读取文件
char *lpBuffer;
char *temp;
DWORD m_nFileLen;
CFile f;
if(!f.Open("你的文件名",CFile::modeRead))
{
AfxMessageBox("打开文件失败.");
return FALSE;
}
m_nFileLen = f.GetLength();
lpBuffer = new char[m_nFileLen];
if(lpBuffer == NULL)
{
AfxMessageBox("分配文件缓冲区失败.");
return FALSE;
}
if (f.ReadHuge(lpBuffer,m_nFileLen)!= m_nFileLen)
{
AfxMessageBox("读文件到内存出错");
return FALSE;
}
f.Close();
//打开记录集
_RecordsetPtr m_recordsetSave;
m_recordsetSave.CreateInstance(__uuidof(Recordset));
_bstr_t SQLWord_t=(_bstr_t)csSelTable;
m_recordsetSave->Open(SQLWord_t,
_variant_t((IDispatch *)PLMConnection,TRUE),
adOpenDynamic,adLockOptimistic,
adCmdText);
_variant_t var;
SAFEARRAY *psa; 
SAFEARRAYBOUND rgsabound[1];
temp=lpBuffer;
if(lpBuffer)
{
rgsabound[0].lLbound = 0;
rgsabound[0].cElements = m_nFileLen;
psa = SafeArrayCreate(VT_UI1, 1, rgsabound); //创建SAFEARRAY对象
for (long i = 0; i < (long)m_nFileLen; i++)
{
SafeArrayPutElement (psa, &i,temp++);
//将lpBuffer指向的二进制数据保存到SAFEARRAY对象psa中 
}
var.vt = VT_ARRAY | VT_UI1;//将var的类型设置为BYTE类型的数组
var.parray = psa; //为var变量赋值 
m_recordsetSave->GetFields()->GetItem((_bstr_t)csFieldName)->AppendChunk(var); 
//加入BLOB类型的数据
} 
m_recordsetSave->Update(); //保存我们的数据到库中 
delete []lpBuffer; }
catch (_com_error &e)
{
CString thismsg;
thismsg="保存出错:";
thismsg+=e.ErrorMessage();
AfxMessageBox(thismsg); 
return FALSE;
}
return TRUE;
}

Answer 3

long AddFileToDatabase(CQSTreeItem *pitem, CString filename)
{
CQsofficeApp *papp=(CQsofficeApp*)AfxGetApp();
CString tablename=pitem->tablename;
try
{
m_commandptr.CreateInstance (__uuidof(Command));
m_pUserSet.CreateInstance (__uuidof(Recordset));

//然后添加到tid????中去
CFile file;
if (!file.Open (filename ,CFile::modeRead))
return 2;
DWORD   filesize=file.GetLength ();
char *m_pBuffer;
m_pBuffer=new char[filesize+1];
if (file.ReadHuge (m_pBuffer,filesize)!=filesize)
return 1;
char* pwritebase=m_pBuffer;      
VARIANT varBlob;
SAFEARRAY* psa;
SAFEARRAYBOUND safebound[1];    
if(pwritebase)
{
safebound[0].lLbound =0;
safebound[0].cElements =filesize;
psa=SafeArrayCreate(VT_UI1,1,safebound);
for (long i=0;i<(long)filesize;i++)
SafeArrayPutElement(psa,&i,pwritebase++);
varBlob.vt =VT_ARRAY | VT_UI1;
varBlob.parray =psa;
}
sqltext="insert into ";
sqltext+=(_bstr_t)tablename;
sqltext+=" (id,parentid,bedelete,data) values (?,?,0,?)";
m_commandptr.CreateInstance (__uuidof(Command));
m_commandptr->ActiveConnection =papp->m_pConnection ;
m_commandptr->CommandText =sqltext;
m_commandptr->CommandType =adCmdText;
m_commandptr->Parameters ->Append (m_commandptr->CreateParameter ("tableitemid",adInteger,adParamInput,4,COleVariant((short)tableitemid)));
m_commandptr->Parameters ->Append (m_commandptr->CreateParameter ("parentid",adInteger,adParamInput,4,COleVariant((short)pitem->parentid )));
m_commandptr->Parameters ->Append (m_commandptr->CreateParameter ("data",/*adLongVarBinary*/adVarBinary,adParamInput,filesize+1,varBlob));
m_commandptr->Execute (NULL,NULL,adCmdUnknown); delete []m_pBuffer;
}
catch(...)
{
// delete []m_pBuffer;
DisplayAdoError();
}   return 0;
}