Modified .SaveChanges(...) to pre-populate primary keys.

EFTest.cs

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Linq;
using System.Text;
using Oracle.DataAccess.Client;
using EFTracingProvider;
using System.IO;
using System.ComponentModel.DataAnnotations;

namespace EFTest1
{
    class Program
    {
        static void Main(string[] args)
        {
            DataTable dt = DbProviderFactories.GetFactoryClasses();
            // Global config switch to enable log to console.
            EFTracingProviderConfiguration.LogToConsole = true;

            using (var ctx = new Context())
            {
                try
                {
                    var obj = ctx.Stops.Find(4217);

                    List<Stop> stops = new List<Stop>();
                    stops.Add(obj);

                    foreach (var s in stops)
                    {
                        if (s.StopNames != null)
                        {
                            List<StopName> snlist = new List<StopName>(s.StopNames);
                            Console.WriteLine(snlist[0].NameWithoutLocality);

                            StopName kirsche = new StopName() 
                            {
                                Id = 0,
                                NameWithLocality = "Kirsche",
                                NameWithoutLocality = "Kirsche",
                                MotId = null,
                                NecId = null,
                                ObId = 3116,
                                TypeId = null,
                                SeqNum = null,
                                NetVersionId = 130,
                                Stop = snlist[0].Stop
                            };

                            //s.StopNames.Add(kirsche);
                            //ctx.SaveChanges("STOP_NAME");
                        }
                    }
                }
                catch (Exception e)
                {
                    Console.WriteLine(e.Message);
                }
            }
        }
    }

    public class IdentityObject
    {
        public decimal Id { get; set; }
    }

    public class Stop : IdentityObject
    {
        public string ShortName { get; set; }
        public decimal NetVersionId { get; set; }
        public short? IsCentralStop { get; set; }

        virtual public ICollection<StopName> StopNames { get; set; }
    }

    public class StopName : IdentityObject
    {
        public string NameWithLocality { get; set; }
        public string NameWithoutLocality { get; set; }
        public decimal? StopId { get; set; }
        public decimal NetVersionId { get; set; }
        public decimal? ObId { get; set; }
        public decimal? MotId { get; set; }
        public decimal? TypeId { get; set; }
        public decimal? SeqNum { get; set; }
        public decimal? NecId { get; set; }

        virtual public Stop Stop { get; set; }
    }

    public class Context : DbContext
    {
        public Context()
            : base(Context.CreateTracingConnection("DATA SOURCE=DEV;PASSWORD=oha12;PERSIST SECURITY INFO=True;USER ID=NET_VVS_TEST", "Oracle.DataAccess.Client"), true)
        {
        }

        public DbSet<Stop> Stops { get; set; }
        public DbSet<StopName> StopNames { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);

            modelBuilder.Conventions.Remove<IncludeMetadataConvention>();
            
            modelBuilder.Entity<Stop>().Property(s => s.ShortName).HasColumnName("STOP_SHORT_NAME");
            modelBuilder.Entity<Stop>().Property(s => s.NetVersionId).HasColumnName("STOP_NV_ID");
            modelBuilder.Entity<Stop>().Property(s => s.IsCentralStop).HasColumnName("STOP_IS_CENTRAL_STOP");
            modelBuilder.Entity<Stop>().Property(s => s.Id).HasColumnName("STOP_ID");
            modelBuilder.Entity<Stop>().HasKey(s => s.Id);
            modelBuilder.Entity<Stop>().ToTable("P_STOP", "NET_VVS_TEST");

            modelBuilder.Entity<StopName>().Property(sn => sn.ObId).HasColumnName("STPN_OB_ID");
            modelBuilder.Entity<StopName>().Property(sn => sn.MotId).HasColumnName("STPN_MOT_ID");
            modelBuilder.Entity<StopName>().Property(sn => sn.TypeId).HasColumnName("STPN_NAME_TYPE");
            modelBuilder.Entity<StopName>().Property(sn => sn.SeqNum).HasColumnName("STPN_NAME_SEQ_NO");
            modelBuilder.Entity<StopName>().Property(sn => sn.NecId).HasColumnName("STPN_NEC_ID");

            modelBuilder.Entity<StopName>().Property(sn => sn.NameWithoutLocality).HasColumnName("STPN_NAME_WITHOUT_LOCALITY");
            modelBuilder.Entity<StopName>().Property(sn => sn.NameWithLocality).HasColumnName("STPN_NAME_WITH_LOCALITY");
            modelBuilder.Entity<StopName>().Property(sn => sn.StopId).HasColumnName("STPN_STOP_ID");
            modelBuilder.Entity<StopName>().Property(sn => sn.NetVersionId).HasColumnName("STPN_NV_ID");
            modelBuilder.Entity<StopName>().Property(sn => sn.Id).HasColumnName("STPN_ID").HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
            modelBuilder.Entity<StopName>().HasKey(sn => sn.Id);
            modelBuilder.Entity<StopName>().HasRequired(sn => sn.Stop).WithMany(s => s.StopNames).HasForeignKey(sn => sn.StopId);
            modelBuilder.Entity<StopName>().ToTable("P_STOP_NAME", "NET_VVS_TEST");
        }

        public static DbConnection CreateTracingConnection(string connectionStr, string providerInvariantName)
        {
            return new OracleConnection(connectionStr);

            string wrapperConnectionString =
            String.Format(@"wrappedProvider={0};{1}", providerInvariantName, connectionStr);

            EFTracingConnection connection =
                new EFTracingConnection
                {
                    ConnectionString = wrapperConnectionString
                };

            return connection;
        }

        // Please note that we can't override the method due to the change to its signature.
        public int SaveChanges(string tableName)
        {
            var objs = from e in this.ChangeTracker.Entries()
                       where e.State == EntityState.Added
                       select e;

            foreach (var obj in objs)
            {
                var ids = this.Database.SqlQuery<decimal>("select NET_VVS_TEST.ID_GENERATOR.GenerateId('" + tableName + "') as NEXTID from dual");
                var o = obj.Entity as IdentityObject;

                foreach (decimal id in ids)
                {
                    if (o != null)
                    {
                        o.Id = id;
                        break;
                    }
                }
            }

            return base.SaveChanges();
        }
    }
}