跨数据库Copy的一个类的代码

#include "StdAfx.h"
#include "./dbcopyclass.h"
CDbCopyClass::CDbCopyClass(void)
{
 ::CoInitialize(NULL);
 pconn.CreateInstance(__uuidof(Connection));
 pSourceConn.CreateInstance(__uuidof(Connection));
 prs.CreateInstance(__uuidof(Recordset));
 m_pCmd.CreateInstance(__uuidof(Command));
 m_SourceRs.CreateInstance(__uuidof(Recordset));
 m_DesRs.CreateInstance(__uuidof(Recordset));
/// m_fields.CreateInstance(__uuidof(Fields));
 //m_fieldPtr.CreateInstance(__uuidof(FieldPtr));
}
CDbCopyClass::~CDbCopyClass(void)
{
 prs.Release();
 m_SourceRs.Release();
 m_DesRs.Release();
 pconn.Release();
 pSourceConn.Release();
 m_pCmd.Release();
 ::CoUninitialize();
}
/***************************************************************************************************
** 函数名  ：RestoreData
** 输  入  ：const CString &desc 目的数据库路径
**           const CString &source 源数据库路径
** 输    出：
** 功能描述：将源数据库中的内容导入到目的数据库中
** 全局变量：
** 调用模块：
** 作    者：刘志永
** 日    期：2008-9-10
** 修    改：
** 日    期：
** 版    本：
***************************************************************************************************/
BOOL CDbCopyClass::RestoreData(const CString &desc, const CString &source)
{
 try
 {
  CString tmpFrom(source);
  CString tmpTo(desc);   
  char buf[512];
  buf[0]='0';
  strcpy(buf,"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=");
  strcat(buf,tmpTo);  
  strcat(buf,";Persist Security Info=False");
  char bufSource[512];
  bufSource[0]='0';
  strcpy(bufSource,"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=");
  strcat(bufSource,tmpFrom); 
  strcat(bufSource,";Persist Security Info=False");
  pconn->ConnectionString=buf; 
  pSourceConn->ConnectionString=bufSource;
  pconn->Open("","","",adConnectUnspecified);
  pSourceConn->Open("","","",adConnectUnspecified);
  prs=pSourceConn->OpenSchema(adSchemaTables);
  m_pCmd->ActiveConnection = pconn;
  while (!prs->adoEOF)
  {
   if (!strcmp((_bstr_t)prs->Fields->GetItem("TABLE_TYPE")->Value,"TABLE"))
   {    
     _bstr_t bstTableName=(_bstr_t)prs->Fields->GetItem("TABLE_NAME")->Value;
        if (m_SourceRs->GetState()==1)
     {
      m_SourceRs->Close();
     }  
     if (m_DesRs->GetState()==1)
     {
      m_DesRs->Close();
     }
     if (bstTableName==_bstr_t("User"))
     {
      bstTableName=_bstr_t("[User]");
     }
     _bstr_t strSqlDel="Delete From "+bstTableName;
     //m_pCmd.
     m_pCmd->CommandText=strSqlDel;
     m_pCmd->CommandType=adCmdText;
     m_pCmd->Execute(NULL,NULL,adCmdText);
     char buf[512];
     buf[0]='0';
     strcpy(buf," SELECT * From ");
     strcat(buf,bstTableName);
     m_SourceRs->CursorType = adOpenStatic;
     m_SourceRs->CursorLocation = adUseClient;
     m_DesRs->CursorType = adOpenStatic;
     m_DesRs->CursorLocation = adUseClient;
     m_SourceRs->Open(buf,_variant_t((IDispatch*)pSourceConn,TRUE),adOpenStatic,adLockOptimistic,adCmdUnknown);
     m_DesRs->Open(buf,_variant_t((IDispatch*)pconn,TRUE),adOpenStatic,adLockOptimistic,adCmdUnknown);
     int nFieldsCount=m_SourceRs->Fields->Count;
     while (!m_SourceRs->adoEOF)
     {
      m_DesRs->AddNew();
      for (int nLoop=0;nLoop<nFieldsCount;nLoop++)
      {
       _variant_t vtIndex;
       vtIndex.vt = VT_I2;
       vtIndex.iVal = nLoop;
       _variant_t tFieldValue=m_SourceRs->Fields->GetItem(vtIndex)->Value;
       m_DesRs->Fields->GetItem(vtIndex)->put_Value(tFieldValue);
      }
      m_DesRs->Update();
      m_SourceRs->MoveNext();
     }
    prs->MoveNext();
  }
   else
    prs->MoveNext();
  }
  prs->Close();
  pconn->Close();
  pSourceConn->Close(); 
  return TRUE;
 }
 catch (...)
 {
  return FALSE;
 }
}