//Sql Server
string connString = ConfigurationSettings.AppSettings[0];
SqlConnection conn = new SqlConnection(connString);
SqlDataAdapter da = new SqlDataAdapter();
string sqlCat = "SELECT CardCode,CardName,CardType,GroupCode FROM ocrd";
da.SelectCommand = new SqlCommand(sqlCat, conn);;
da.Fill(ds, "ocrd");
//Excel
string filepath=Server.MapPath(".")+"/SBODemo_Chinese.xls" ;
string strCon="Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source ="+filepath.Trim()+";Extended Properties=Excel 8.0";
OleDbConnection myConn = new OleDbConnection(strCon);
string strCom="select GroupCode from [Sheet1$] as sheet";
myConn.Open();
OleDbDataAdapter Oda = new OleDbDataAdapter(strCom,myConn);
Oda.Fill(ds,"sheet");
myConn.Close();
//Relation
DataRelation relat = new DataRelation("SqlXls",
ds.Tables["ocrd"].Columns["GroupCode"],
ds.Tables["sheet"].Columns["GroupCode"]);