PHP：Localhost重定向您太​​多次

Question

I want to check in login page if one user already login in the system its go to index page. But the code i used had an error like this

localhost redirected you too many times. Try clearing your cookies. ERR_TOO_MANY_REDIRECTS

and this is my code to check the user is login or not. Thanks

<?php
session_start();
include '../pages/koneksi.php';
if(isset($_SESSION['username'])){
    $username = $_SESSION['username'];
    $res = mysqli_query($link, "select * from tb_user where username = '$username';");
    $user = mysqli_fetch_array($res);
    $_SESSION['ID']=$user['ID'];
    header("location: index.php");
    die();
    } else {
       header("location: login.php");
    }
?>

And this is the index file

<?php
session_start();
include '../pages/koneksi.php';
//check session udah login apa belum
if(isset($_SESSION['username'])){
    $username = $_SESSION['username'];
    $res = mysqli_query($link, "select * from tb_user where username = '$username';");
    $user = mysqli_fetch_array($res);
    $_SESSION['ID']=$user['ID'];
} else {
    header("location: login.php");
}
?>

Answer 1

Do this... On

index.php

<?php
    session_start();
    include '../pages/koneksi.php';
    if(!isset($_SESSION['username'])){header("location: login.php");}
?>

And on

login.php

<?php
    session_start();
    include '../pages/koneksi.php';
    if(isset($_SESSION['username'])){header("location: index.php");}
?>

Don't add these code on same page... both code are opposite of each other.

If you add them in same page then if or else condition runs every page load....