Issue with PDO Connection - php

Question

i am new to this so dont be rude :D
I have 3 file: database.php, init.php and user.php
Here the init.php:
<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
session_start();
require 'database.php';
require 'functions/user.php';
$errors = array();
Here the database.php:
<?php
$db_host = "localhost";
$db_name = "xxxx";
$db_user = "xxxx";
$db_pw = "xxxx";
try {
$conn = new PDO("mysql:host=$db_host;dbname=$db_name;", $db_user, $db_pw);
} catch(PDOException $e) {
die("Verbindung fehlgeschlagen: " . $e->getMessage());
}
And here the user.php:
<?php
function userExists($user) {
$sql = "SELECT * FROM user WHERE email = :email";
$stmt = $conn->prepare($sql);
$stmt->bindParam(':email', $user);
$stmt->execute();
$results = $stmt->fetch(PDO::FETCH_ASSOC);
if(count($results) > 0) return true;
return false;
}
So the error message:
Notice: Undefined variable: conn in /mnt/web109/b2/35/57848035/htdocs/includes/functions/user.php on line 4 Fatal error: Call to a member function prepare() on null in /mnt/web109/b2/35/57848035/htdocs/includes/functions/user.php on line 4
The function userExists() is called in another file named login.php. In login.php i have already required init.php. The error message appears when i want to login.
So i hope you can help me.
Thx

Answer 1

$conn is not available in your function since it is in a different scope. Pass it as a parameter or declare it as a global variable.
function userExists($user, $conn){
// ...
}
or
function userExists($user){
global $conn;
// ...
}

Answer 2

In your userExists function you are calling $conn variable which isn't global scope (Give a small look here)..
You can use one of these:
function userExists($user, $conn){
$sql = "SELECT * FROM user WHERE email = :email";
$stmt = $conn->prepare($sql);
$stmt->bindParam(':email', $user);
$stmt->execute();
$results = $stmt->fetch(PDO::FETCH_ASSOC);
if(count($results) > 0) return true;
return false;
}
OR
function userExists($user){
global $conn; //<--- bad practi
$sql = "SELECT * FROM user WHERE email = :email";
$stmt = $conn->prepare($sql);
$stmt->bindParam(':email', $user);
$stmt->execute();
$results = $stmt->fetch(PDO::FETCH_ASSOC);
if(count($results) > 0) return true;
return false;
}
OR
use of $GLOBALS variable
function userExists($user){
$sql = "SELECT * FROM user WHERE email = :email";
$stmt = $GLOBALS['conn']->prepare($sql);
$stmt->bindParam(':email', $user);
$stmt->execute();
$results = $stmt->fetch(PDO::FETCH_ASSOC);
if(count($results) > 0) return true;
return false;
}