PHP MySQL: Updating users profile - php

Question

I got a problem for my profile page in my login system. When I want to update the user's username and email, I can only update one of the two. Look where I putted the points. If I use username it only updates the username and the same goes for the email.
Here is my code:
function updateProfile($db, $errors)
{
$id = $_SESSION['user']['id'];
$username = mysqli_real_escape_string($db, $_POST['username']);
$email = mysqli_real_escape_string($db, $_POST['email']);
$field_check_query = "SELECT * FROM users WHERE username='$username' email='$email'";
$result = mysqli_query($db, $field_check_query);
$field = mysqli_fetch_assoc($result);
// Checks if username is already taken
if ($field) {
if ($field['username'] === $username) {
array_push($errors, "Gebruikersnaam is al reeds ingenomen");
}
// Checks if email is already taken
if ($field['email'] === $email) {
array_push($errors, "E-mailadres is al reeds ingenomen");
}
}
if (count($errors) == 0) {
if (isset($_POST['.......'])) {
$query = "UPDATE users SET username='$username' email='$email' WHERE id=$id";
mysqli_query($db, $query);
header('location: profile.php?profileeditedsuccesfully');
die($query);
}
}
}

Answer 1

Add AND to WHERE in Select:
$field_check_query = "SELECT * FROM users WHERE username='$username' AND email='$email'";
Add comma to separate the pairs in Update.
=$query = "UPDATE users SET username='$username', email='$email' WHERE id=$id";