MySQL connection works on Localhost but not on webserver - php

Question

Good day Everyone..
I have an issue that is puzzling me and I can not seem to find a way to solve it. Even the tech support in my hosting service can not solve it.
I have created a small script to do a simple task. I require the employees to log in to perform any said task.
I have tested the application on a development server and the login script works perfectly, but when I place it on the webserver the connection is never established.
I use the same username and passowrd in the dbcon.php file to log in using phpMyAdmin and it works, and I run the queries and they also work.
Here are the files:
1: dbcon.php
<?php
$connect = "mysql:host=localhost;dbname=mdchaara_draiwil_dms;charset=utf8";
$db_user = "dbusername";
$db_pass = "dbpassword";
$db = new PDO($connect,$db_user,$db_pass);
?>
2: login.php:
<?php
session_start();
require "../../_dbcon/_dbcon.php";
//Timezone settings:
$timezone = "Asia/Kuwait";
if(function_exists('date_default_timezone_set')) date_default_timezone_set($timezone);
// check the username has only alpha numeric characters
if (ctype_alnum($_POST['username']) != true)
{
//if there is no match
$message = "Username must be alpha numeric";
}
//check the password has only alpha numeric characters ***/
if (ctype_alnum($_POST['password']) != true)
{
//if there is no match ***/
$message = "Password must be alpha numeric";
}
else
{
// if we are here the data is valid and we can insert it into database
$username = filter_var($_POST['username'], FILTER_SANITIZE_STRING);
$password = filter_var($_POST['password'], FILTER_SANITIZE_STRING);
//SQL Injection Precaution:/
$username = stripslashes($username);
$password = stripslashes($password);
try
{
//Select Statement:
$stmt = $db->query("SELECT *
FROM dms_gt_users
WHERE username = '$username' AND password = '$password'");
$result = $stmt->rowCount();
}
catch(PDOException $ex) {
echo "An Error occured!"; //user friendly message
some_logging_function($ex->getMessage());
}
// If result matched $username and $password, there will be one row
if($result==1){
// check if the account is active:
$stmt = $db->query("SELECT id_status
FROM dms_gt_users
WHERE username = '$username' AND password = '$password'");
while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
$id_status= $row['id_status'];
}
$stmt = $db->query("SELECT employee_id
FROM dms_gt_users
WHERE username = '$username' AND password = '$password'");
while($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
$employee_id= $row['employee_id'];
}
//Check if account is active:
if($id_status == "A"){
// Create Session ID:
$session_id = "";
$_SESSION['sid'] = "";
$session_id = mt_rand(100000, 999999);
$sid_update = $db->query("UPDATE dms_gt_users
SET `session_id`='$session_id'
WHERE username='$username' and password ='$password'");
$_SESSION['sid'] = $session_id;
//Get last login details:
$current_login = date("Y-m-d H:i:s");
$stmt = $db->query('SELECT `last_log_in`
FROM dms_gt_users
WHERE `employee_id` = '.$employee_id);
while($row = $stmt->fetch(PDO::FETCH_ASSOC)){
$last_log_in = $row['last_log_in'];
}
$_SESSION['last_log_in'] = $last_log_in;
//get IP address:
$ip = getenv('REMOTE_ADDR');
//Add login details to Activity Log:
$stmt = $db->query("INSERT INTO dms_activity_log
(`employee_id`, `activity_date_time`, `activity`, `ip_address`)
VALUES ('$employee_id', '$current_login', 'Logged in', '$ip')");
//Add login details to users table:
$stmt = $db->query("UPDATE dms_gt_users
SET `last_log_in`='$current_login'
WHERE username='$username' and password ='$password'");
//update session login
$_SESSION['login']= 1;
//save employee id to session
$_SESSION['employee_id'] = $employee_id;
// redirect to portal home:
header ("Location:../../../home.php");
}
//Account is not Active:
else{
header ("Location:../../../index.php");
}
}
//Username or password are incorrect
else {
header ("Location:../../../index.php");
}
}
?>
What am I doing wrong? and if my code is ok, what should I tell the hosting Tech Support to look for?
Thanks!!
EDIT
#noc2spam: I have updated the connection string as you have advised, I get no errors logged. I var_dump the $db, and I get object(PDO)#1 (0)

Answer 1

It is pretty hard to tell why this is happening without looking into the server itself. I suggest that you enable the Exception mode so that you can see what the problem is. For example:
try {
$connect = "mysql:host=localhost;dbname=mdchaara_draiwil_dms;charset=utf8";
$db_user = "dbusername";
$db_pass = "dbpassword";
$db = new PDO($connect,$db_user,$db_pass);
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
catch (PDOException $e) {
echo 'PDO Exception: '.$e->getMessage();
die();
}
It would be much easier to troubleshoot now. Check if you are getting any error and update the original question with the message if possible. I will edit this answer after that.

Answer 2

IF Roger Ng's answer doesn't solve it, then you may have a firewall blocking your connection. Check your mysql server port... typically 3306.

Answer 3

Check your database's url. Generally, in shared/dedicated hosting environment, DB server and App Server are on different machines. Also, many service providers do not provide mysql cluster services on port 3306. So, please get the correct URL and port of the database from your hosts CPanel or tech support team.
Also, add the App server's IP address to the permitted IP addresses list in Remote MySQL Cpanel interface.