private void comboBoxLoad() { MySqlConnection conn = new MySqlConnection(Login.connectionString); DataSet ds = new DataSet(); try { conn.Open(); MySqlCommand cmd = new MySqlCommand("select * from login_details inner join employee on login_details.employeeId=employee.employeeId where login_details.authLevel='Doctor'", conn); MySqlDataAdapter da = new MySqlDataAdapter(); da.SelectCommand = cmd; da.Fill(ds); doctorEntry.DisplayMember = "employeeId"; doctorEntry.ValueMember = "employeeId"; doctorEntry.DataSource = ds.Tables[0]; doctorEntry2.DisplayMember = "employeeId"; doctorEntry2.ValueMember = "employeeId"; doctorEntry2.DataSource = ds.Tables[0]; } catch (Exception ex) { //Exception Message } finally { conn.Close(); conn.Dispose(); } string query = "select employee.employeeId,fname,lname from employee inner join login_details on employee.employeeId=login_details.employeeId where login_details.authLevel='Doctor'"; Crud employeeList = new Crud(); employeeList.createTable2(query, doctorList); Crud employeeList2 = new Crud(); employeeList2.createTable2(query, doctorList2); }