error while retrieving data.

System.NotImplementedException: The method or operation is not implemented.

public List<Emp> GetEmp()
        {
            try
            {
                List<Emp> lst = new List<Emp>();
                string query = "Select empid, emmpname, jobid, managerid, hiredate, salary, comm, departmentid from employee";
                con = new SqlConnection(connect);
                cmd = new SqlCommand(query, con);
                con.Open();
                dr = cmd.ExecuteReader();
                while (dr.Read())
                {
                    Emp e = new Emp();
                    e.empid = (int)dr["empid"];
                    e.empname = dr["emmpname"].ToString();
                    e.jobid = (int)dr["jobid"];
                    e.managerid = (int)dr["managerid"];
                    e.hiredate = (DateTime)dr["hiredate"];
                    e.salary = (int)dr["salary"];
                    e.comm = (int)dr["comm"];
                    e.deptid = Convert.ToInt32(dr["departmentid"]);
                    lst.Add(e);
                }
                return lst;
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                con.Close();
            }
        }