---

       using var context = new PortContext();

       var r1 = context.Ships.Where(s => s.ShipTypeId == 1);
       var r2 = context.Ships.Where(s => s.Flag == "Панама");
       var r3 = context.Ships.Where(s => s.Flag != "Россия");
       var r4 = context.Ships.Where(s => s.Flag == "Мальта" && s.Flag == "Либерия");
       var r5 = context.Ships.Where(s => s.BuiltYear >= 2005 && s.BuiltYear <= 2015);
       var r6 = context.Ships.Where(s => s.LengthM > 250);
       var r7 = context.Ships.Where(s => s.DeadweightT < 30000);
       var r8 = context.Ships.Where(s => s.Name.ToLower().Contains("а"));
       var r9 = context.Ships.Where(s => s.Name.StartsWith("A"));
       var r10 = context.Ships.Where(s => (s.Name[0] >= 'А' && s.Name[0] <= 'Я') || (s.Name[0] >= 'а' && s.Name[0] <= 'я'));
       var r11 = context.Ships.Where(s => s.Flag == "Россия" && s.BuiltYear >= 2005);
       var r12 = context.Berths.Where(b => b.MaxLengthM > 250);
       var r13 = context.Berths.Where(b => b.MaxDraftM < 12);
       var r14 = context.Berths.Where(b => b.IsActive == false);
       var r15 = context.Berths.Where(b => b.Code.StartsWith("B"));
       var r16 = context.PortCalls.Where(p => p.Status == "departed");
       var r17 = context.PortCalls.Where(p => p.Arrival >= new DateTime(2026, 8, 1) && p.Arrival < new DateTime(2026, 9, 1));
       var r18 = context.PortCalls.Where(p => p.BerthId == 1);
       var r19 = context.PortCalls.Where(p => p.Departure != null);
       var r20 = context.PortCalls.Where(p => p.Arrival.TimeOfDay < new TimeSpan(12, 0, 0));
       var r21 = context.PortCalls.Where(p => p.Arrival.DayOfWeek == DayOfWeek.Saturday || p.Arrival.DayOfWeek == DayOfWeek.Sunday);
       var r22 = context.CargoTypes.Where(ct => ct.IsDangerous == false);
       var r23 = context.CargoOperations.Where(co => co.Operation == "unload");
       var r24 = context.CargoOperations.Where(co => co.QuantityT > 20000);
       var r25 = context.CargoOperations.Where(co => co.CargoTypeId == 1 && co.PortCallId == 1);
       
       int[] shipIds = { 2, 4, 6 };
       var r26 = context.Ships.Where(p => shipIds.Contains(p.Id));