Ado的特殊使用方法

来源：互联网发布：笔记本电脑录屏软件编辑：程序博客网时间：2024/04/28 21:57

1、建立数据库

BOOL CDataConfigCls::CreateDataBase(CString &szFileName,LPCSTR szCnn/* =NULL*/)
{
CString strCnn;
if(szCnn==NULL)
{
  CString strTmp = m_strAppPath+"//"+szFileName;
  CFileFind chFind;
  if(!chFind.FindFile(strTmp))
  {
   ADOX::_CatalogPtr pAdoX=NULL;//不用RELEASE，自动会释放
   try{

    pAdoX.CreateInstance(_T("ADOX.Catalog"));
    strTmp.Format(_T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=%s"),m_strAppPath+"//"+szFileName);
    pAdoX->Create((LPCTSTR)strTmp);//创建数据库
   }
   catch (...) {
    return FALSE;
   }
  }
  m_strDbFile = m_strAppPath+"//"+szFileName;
  strCnn="Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+m_strDbFile+";Persist Security Info=False;";
}
else
{
  strCnn =szCnn;
}

try
{

  m_pCnn.CreateInstance(__uuidof(Connection));
  m_pCnn->Open((LPCSTR)strCnn,"","",adConnectUnspecified);

}
catch(_com_error e)
{
  return FALSE;
}
return CreateTable();

}

2-判断表是否存在
BOOL CDataConfigCls::TableExisted(CString &tableName)
{
if(adStateOpen!=m_pCnn->State) return FALSE;
try
{
  _RecordsetPtr pRst = NULL;
  pRst = m_pCnn->OpenSchema(adSchemaTables);
  _variant_t vtTmp;
  vtTmp = "TABLE_TYPE='TABLE'";
  pRst->put_Filter(vtTmp);
  if(NULL==pRst) return FALSE;
  if(pRst->GetRecordCount()>0)
   pRst->MoveFirst();

  CString szTmp;
  while (!pRst->adoEOF) {
   vtTmp=pRst->GetCollect("TABLE_NAME");
   szTmp = vtTmp.vt==VT_NULL?"":(char*)(_bstr_t)vtTmp;
   szTmp.MakeUpper();
   tableName.MakeUpper();
   if( szTmp==tableName)
   {
    return TRUE;
   }
   pRst->MoveNext();
  }
}
catch (_com_error e) {
  return FALSE;
}
return FALSE;
}