I have two classes Class1 and Class2
[Table("CLASS1", Schema = "public")]
    public class Class1
    {
        public int Class1Id { get; set; }
        public string Name1 { get; set; }
    }
[Table("CLASS2", Schema = "public")]
    public class Class2
    {
        public int Class2Id { get; set; }
        public string Name2 { get; set; }
        public int Class1Id { get; set; }
        public virtual Class1 c1 { get; set; }
I defined the DatabaseContext :
public sealed class     DatabaseContext : DbContext
    {
        private static readonly DatabaseContext instance = new DatabaseContext();
        public static DatabaseContext Instance
        {
            get
            {
                return instance;
            }
        }
        private DatabaseContext()
            : base("maconnexion")
        {
            Database.SetInitializer<DatabaseContext>(null);
        }
        public DbSet<Class1> table1{ get; set; }
        public DbSet<Class2> table2{ get; set; }
    }
and i have added those lines to my App.config
<DbProviderFactories>
      <add name="Npgsql Data Provider" invariant="Npgsql" description="Data Provider for PostgreSQL" type="Npgsql.NpgsqlFactory, Npgsql" />
    </DbProviderFactories>
 <connectionStrings>
    <add name="maconnexion"
 connectionString="Server=127.0.0.1;Port=5432;Database=DB_Ticketing;UserId=postgres;Password=slots2013;" providerName="Npgsql" />
  </connectionStrings>
and I have created a database in PostgreSQL with the name DB_Ticketing. But when I execute my code the tables table1 and table2 are not added to my data base.