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