Linq语句：三表联查

var db = new DataEntities2();
            var sss = ( from c in db.AIRPORT_HELIPORT
                               from t in db.AIRPORT_HELIPORT_TS
                               from v in db.EX_VERSION
                               where c.AIRPORT_HELIPORT_UUID == t.AIRPORT_HELIPORT_UUID
                                     && t.EFFVERSION_ID == v.VERSION_ID
                                     && v.VERSION_NUMBER == 201799
                               select c.AIRPORT_HELIPORT_UUID
                            ).ToList();