How to view other users profile if session is set in php - php

Question

Well I am trying to create kind of a social network but there is a problem with my session. So I am not able to visit other users profile. This is my code for loginwebsite1.php
<?php
ob_start();
session_start();
$connection = mysqli_connect('localhost', 'root', '123456789', 'register');
if (isset($_POST['email1'])) {
$email = mysqli_real_escape_string($connection, htmlentities($_POST['email1']));
}
if (isset($_POST['password1'])) {
$password = mysqli_real_escape_string($connection, htmlentities($_POST['password1']));
}
if (!empty($email) && !empty($password)) {
$query = "select id from register where email='$email' and password='$password'";
$result = mysqli_query($connection, $query);
$row = mysqli_fetch_array($result);
if ($row > 0) {
$_SESSION['id'] = $row;
$_GET['id'] = $row;
header('location: new.php');
} else {
echo "sorry but the email-id or password is wrong";
}
} else {
echo "please enter your email-id or password or there";
}
?>
My session code goes like this:
<?php
ob_start();
session_start();
if (isset($_SESSION['id']) && !empty($_SESSION['id'])) {
$id = $_SESSION['id'];
foreach ($id as $fn)
$connection = mysqli_connect('localhost', 'id', 'password', 'register');
$query = "select firstname,lastname from register where id='$fn'";
$result = mysqli_query($connection, $query);
$row = mysqli_fetch_array($result);
$firstname = $row['firstname'];
$lastname = $row['lastname'];
} else {
header('location: loginwebsite1.php');
}
?>
But when I try to enter like profile.php?id=9 it still opens the profile of the user who is logged in.

Answer 1

$id=$_SESSION['id'];
This line is where you problem is I believe. Here you get the ID number for the profile page to load from the $_SESSION variable when you should be getting it from the $_GET variable.
It should read:
$id=$_GET['id'];

Answer 2

you should also check if the $_GET['id'] is also set like this
$connection=mysqli_connect('localhost','id','password','register');
if(isset($_SESSION['id']) && !empty($_SESSION['id']) || !empty($_GET['id']))
{
$id=!empty($_GET['id'])? $_GET['id']: $_SESSION['id'];
foreach($id as $fn){
$query="select firstname,lastname from register where id='$fn'";
$result=mysqli_query($connection,$query);
$row=mysqli_fetch_array($result);
$firstname=$row['firstname'];
$lastname=$row['lastname'];
}
}else{
header('location: loginwebsite1.php');
}
also set your $connection variable to connect only once to your database.