public DMaDieuKhienThietBiCollection FetchAll()
 {
     DMaDieuKhienThietBiCollection coll = new DMaDieuKhienThietBiCollection();
     Query qry = new Query(DMaDieuKhienThietBi.Schema);
     coll.LoadAndCloseReader(qry.ExecuteReader());
     return coll;
 }
 public DMaDieuKhienThietBiCollection FetchByQuery(Query qry)
 {
     DMaDieuKhienThietBiCollection coll = new DMaDieuKhienThietBiCollection();
     coll.LoadAndCloseReader(qry.ExecuteReader()); 
     return coll;
 }