public partial class DataContext : DbContext, IDataContext
{
    public DataContext()
        : base("name=DataContext")
    {
    }

    public DataContext(DbConnection existingConnection, bool contextOwnsConnection) : base(existingConnection, contextOwnsConnection)
    {

    }

    public string UserID { get; set; }

public override int SaveChanges()
    {
        SetDbSession();
        return base.SaveChanges();
    }

private void SetDbSession()
    {
        //Open a connection to the database so the session is set up
        this.Database.Connection.Open();
        //Set the db session
        //ExecuteSqlCommand ot to be used as it will close the connection
        using (var cmd = this.Database.Connection.CreateCommand())
        {
            var parm = cmd.CreateParameter();
            parm.ParameterName = "@userId";
            parm.Value = UserID ;
            cmd.CommandText = "SetDbSession";
            cmd.CommandType = System.Data.CommandType.StoredProcedure;
            cmd.Parameters.Add(parm);
            cmd.ExecuteNonQuery();
    };
}