External file with PDO connection not working - php

Question

I realize this question has been asked in some form or another multiple times, but none of the solutions on the other versions of this question work for me.
These two files have no issues:
/blog/login.php
<?php
include('core/init.php');
if (empty($_POST) === false){
$username = $_POST['username'];
$password = $_POST['password'];
if (empty($username) || empty($password)) {
$errors[] = 'Missing username and/or password.';
} else if (user_exists($username) === false) {
$errors[] = 'User doesn\'t exist.';
}else if (user_active($username) === false) {
$errors[] = 'User account not activated.';
}else {
//
}
print_r($errors);
}
?>
/blog/core/init.php
<?php
require('database/connect.php');
require('functions/users.php');
require('functions/general.php');
session_start();
$errors = array();
?>
I'm just including them to show you how connect.php is require()'d (indirectly) in users.php.
/blog/core/database/connect.php
<?php
$dbname = "xxx_forms";
$servername = "mysql.xxx.com";
$usr= "xxx_xxx";
$pass = "xxxxxxxx";
$pdo = new PDO("mysql:host=$host;dbname=$dbname", $usr, $pass);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
?>
This connection itself doesn't trigger any errors...
/blog/core/functions/users.php
<?php
function user_exists($username) {
$ret = '';
try {
$sql = "SELECT COUNT(id) FROM registration WHERE user = '$username';";
$q = $pdo->query($sql);
$f = $q->fetch();
$ret = $f[0];
} catch (PDOException $e) {
die("Could not connect to the database $dbname :" . $e->getMessage());
}
return ($ret == 1) ? true : false;
}
However, when we get to users.php, I always get an error at the $q = $pdo->query($sql); line, apparently because PHP doesn't know what $pdo is. On the other hand, when I include the code from connect.php, so that it is not in an external file (exactly like below, but not commented out):
function user_exists($username) {
//$dbname = "xxx_forms";
//$servername = "mysql.xxx.com";
//$usr= "xxx_xxx";
//$pass = "xxxxxxxx";
$ret = '';
try {
//$pdo = new PDO("mysql:host=$host;dbname=$dbname", $usr, $pass);
$sql = "SELECT COUNT(id) FROM registration WHERE user = '$username';";
$q = $pdo->query($sql);
$f = $q->fetch();
$ret = $f[0];
} catch (PDOException $e) {
die("Could not connect to the database $dbname :" . $e->getMessage());
}
return ($ret == 1) ? true : false;
}
...everything works the way it is supposed to.
How do I make it work when the PDO connection is done in the external file connect.php?

Answer 1

Further to my comment, you need to do something like this:
/config.php
<?php
define('DS',DIRECTORY_SEPARATOR);
define('DB_HOST','localhost');
define('DB_NAME','database');
define('DB_USER','root');
define('DB_PASS','');
define('ROOT_DIR',__DIR__);
define('FUNCTIONS',ROOT_DIR.DS.'functions');
# Add the connection function
require_once(FUNCTIONS.DS.'connect.php');
# Start session
session_start();
# Get the connection
$pdo = connect();
/functions/connect.php
function connect()
{
$pdo = new PDO("mysql:host=".DB_HOST.";dbname=".DB_NAME, DB_USER, DB_PASS);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
return $pdo;
}
/functions/user_exists.php
<?php
function user_exists($pdo,$username)
{
$ret = 0;
try {
$sql = "SELECT COUNT(id) as count FROM registration WHERE user = :username";
$q = $pdo->prepare($sql);
$q->execute(array(":username"=>$username));
$f = $q->fetch(PDO::FETCH_ASSOC);
$ret = $f['count'];
}
catch (PDOException $e) {
die("Could not connect to the database ".DB_NAME.":" . $e->getMessage());
}
return ($ret == 1);
}
Here is an example of use:
/index.php
<?php
# Add the basic stuff
require(__DIR__.DIRECTORY_SEPARATOR.'config.php');
# Add our functions
require(FUNCTIONS.DS.'user_exists.php');
require(FUNCTIONS.DS.'general.php');
# Example of use
print_r(user_exists($pdo,'username#email.com'));