public DistrictCollection() { Districts = new List <District>(); CountryCollection countryCollection = new CountryCollection(); this.Districts.Add(new District(11, "Витебская обл.", countryCollection.Countries.Find(c => c.CountryCode == 1))); this.Districts.Add(new District(22, "Брестская обл.", countryCollection.Countries.Find(c => c.CountryCode == 2))); this.Districts.Add(new District(31, "Новый Южный Уэльс", countryCollection.Countries.Find(c => c.CountryCode == 3))); this.Districts.Add(new District(41, "Виктория", countryCollection.Countries.Find(c => c.CountryCode == 4))); }
static void Main(string[] args) { List <Country> cc = new CountryCollection().Countries; List <District> dc = new DistrictCollection().Districts; List <City> ctc = new CityCollection().Cities; List <Neighborhood> nbc = new NeighborhoodCollection().Neighborhoods; var results = from country in cc join d in dc on country.CountryCode equals d.Country.CountryCode join ct in ctc on d.DistrictCode equals ct.District.DistrictCode join nb in nbc on ct.CityCode equals nb.City.CityCode select new { nb.StreetName }; foreach (var result in results) { Console.WriteLine($"street: {result.StreetName}"); } Console.ReadKey(); }