b.cs

using System.Collections.Generic;
using System.Linq;

namespace Model
{
    public class BoatDAL
    {

        public List<Boat> FetchAll()
        {
            using (var ctx = new RPPP14Entities())
            {
                return ctx.Boats.ToList();
            }
        }

        public Boat Fetch(int boatId)
        {
            using (var ctx = new RPPP14Entities())
            {
                return ctx.Boats.SingleOrDefault(b => b.Id == boatId);
            }
        }

        public void Insert(Boat newBoat)
        {
            using (var ctx = new RPPP14Entities())
            {
                ctx.Boats.Add(newBoat);
                ctx.SaveChanges();
            }
        }

        public void Update(Boat newBoat)
        {
            using (var ctx = new RPPP14Entities())
            {
                //izbrisi stari sa istim id
                var oldBoat = ctx.Boats.Single(boat => boat.Id == newBoat.Id);
                ctx.Boats.Remove(oldBoat);
                //dodaj novi na isti id
                ctx.Boats.Add(newBoat);
                ctx.SaveChanges();
            }
        }

        public void Delete(int id)
        {
            using (var ctx = new RPPP14Entities())
            {
                var b = ctx.Boats.Single(boat => boat.Id == id);
                ctx.Boats.Remove(b);
                ctx.SaveChanges();
            }
        }
    }

}