Php database handling - php

Question

I'm working on a php page that compare information received by a client with information in a database, but I'm not so good in php and I don't know what I did wrong, I always get response code 500, internal server error.
Here is the code:
<?php
/**
* #var object $payload The payload sent from the client
*/
$payload = json_decode(file_get_contents("php://input"), true);
/**
* #var object $user_name The username sent by the client
* #var object $user_name The password sent by the client
*/
$user_name = $payload['username'];
$user_password = $payload['password'];
$response = null;
$responseCode = 200;
$result_row = null;
/**
* The form representing a positive response
*/
class Response {
public $accessToken = "";
public $availableProfiles = "";
public $selectedProfile = "";
}
/**
* The form representing a negative response
*/
class negativeResponse {
public $error = "";
public $errorMessage = "";
}
/**
* #var object $db_connection The database connection
*/
$db_connection = null;
try {
$db_connection = new PDO('mysql:host=localhost;dbname=launcher_login;charset=utf8', 'myUser', 'myPass');
} catch (PDOException $e) {
//Catch exception
}
// user can login with his username or his email address.
// if user has not typed a valid email address, we try to identify him with his user_name
if (!filter_var($user_name, FILTER_VALIDATE_EMAIL)) {
// database query, getting all the info of the selected user
$query_user = $this->db_connection->prepare('SELECT * FROM users WHERE user_name = :user_name');
$query_user->bindValue(':user_name', $user_name, PDO::PARAM_STR);
$query_user->execute();
// get result row (as an object)
$result_row = $query_user->fetchObject();
// if user has typed a valid email address, we try to identify him with his user_email
} else {
// database query, getting all the info of the selected user
$query_user = $db_connection->prepare('SELECT * FROM users WHERE user_email = :user_email');
$query_user->bindValue(':user_email', trim($user_name), PDO::PARAM_STR);
$query_user->execute();
// get result row (as an object)
$result_row = $query_user->fetchObject();
}
// if this user not exists
if (!isset($result_row->user_id)) {
$response = new negativeResponse();
$response->error = "Credenziali Invalide";
$response->errorMessage = "Non esiste un account con questa combinazione nome utente/password";
$responseCode=201;
// if the password isn't correct
} else if (!password_verify($user_password, $result_row->user_password_hash)) {
$response = new negativeResponse();
$response->error = "Credenziali Invalide";
$response->errorMessage = "Non esiste un account con questa combinazione nome utente/password";
$responseCode=201;
// if the account exists but it isn't activated
} else if ($result_row->user_active != 1) {
$response = new negativeResponse();
$response->error = "Account non attivo";
$response->errorMessage = "Devi attivare l'account! Controlla l'email inserita";
$responseCode=201;
} else {
$response = new Response();
$response->accessToken = hash('md5', $user_name);
$response->availableProfiles = array(array('id' => hash('md5', $user_name), 'name' => $user_name, 'legacy' => true));
$response->selectedProfile = array('id' => hash('md5', $user_name), 'name' => $user_name, 'legacy' => true);
}
echo json_encode($response);
http_response_code($responseCode);
My table is created with this query:
CREATE TABLE IF NOT EXISTS `launcher-login`.`users` (
`user_id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'auto incrementing user_id of each user, unique index',
`user_name` varchar(64) COLLATE utf8_unicode_ci NOT NULL COMMENT 'user''s name, unique',
`user_password_hash` varchar(255) COLLATE utf8_unicode_ci NOT NULL COMMENT 'user''s password in salted and hashed format',
`user_email` varchar(64) COLLATE utf8_unicode_ci NOT NULL COMMENT 'user''s email, unique',
`user_active` tinyint(1) NOT NULL DEFAULT '0' COMMENT 'user''s activation status',
`user_activation_hash` varchar(40) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT 'user''s email verification hash string',
`user_password_reset_hash` char(40) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT 'user''s password reset code',
`user_password_reset_timestamp` bigint(20) DEFAULT NULL COMMENT 'timestamp of the password reset request',
`user_rememberme_token` varchar(64) COLLATE utf8_unicode_ci DEFAULT NULL COMMENT 'user''s remember-me cookie token',
`user_failed_logins` tinyint(1) NOT NULL DEFAULT '0' COMMENT 'user''s failed login attemps',
`user_last_failed_login` int(10) DEFAULT NULL COMMENT 'unix timestamp of last failed login attempt',
`user_registration_datetime` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
`user_registration_ip` varchar(39) COLLATE utf8_unicode_ci NOT NULL DEFAULT '0.0.0.0',
PRIMARY KEY (`user_id`),
UNIQUE KEY `user_name` (`user_name`),
UNIQUE KEY `user_email` (`user_email`)
) ENGINE=MyISAM AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci COMMENT='user data';
EDIT: I feel stupid, the error was $query_user = $this->db_connection->prepare('SELECT * FROM users WHERE user_name = :user_name');. I was using this outside of a class, now I'm working on the client part, thank you all for help

Answer 1

I'm almost certain the issue is that $db_connection is null since the connection is failing. Based on what you provided your database name should be launcher-login instead of launcher_login as you've specified in your connection string. As such the following edit should fix your problem.
try {
$db_connection = new PDO('mysql:host=localhost;dbname=launcher-login;charset=utf8', 'myUser', 'myPass');
} catch (PDOException $e) {
echo 'Unable to connect to database'; exit;
}