Having Trouble with PDO, but No Errors

Question

I am playing around with PDO, but something weird is happening that I cannot seem to figure out. There are no errors being produced. Just nothing being inserted into the database.

index.php

<?php
error_reporting(E_ALL); 
require('includes/classes.php');
require_once('includes/config.php');

$db = new DatabaseCon();
$db->dbConnect($config);

$stmt = $db->prepare("INSERT INTO images (filename) VALUES (?)");
$stmt->bindParam(1, "hello world!");
$stmt->execute();
?>

classes.php

<?php
error_reporting(E_ALL);
require('config.php');

// Connect to database
// Does not handle anything else
class DatabaseCon {
    public $dbh;

    // Method to connect to database
    function dbConnect($config) {
        try {
            $dbh = new PDO("mysql:host=" . $config['host'] . ";dbname=" . $config['dbname'], $config['dbuser'], $config['dbpass']);
            //$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT);
        } catch (PDOException $e) {
            echo $e->getMessage();
        }
    }
}

config.php

<?php
error_reporting(E_ALL);

$config = array(
    'host' => 'localhost',  // Database hostname (usually localhost)
    'dbuser' => 'admin_mp', // Database username
    'dbpass' => 'mypassword here', // Database password
    'dbname' => 'mpdb' // Database name
);

When I navigate to index.php, "hello world" should be inserted into the database, but it's not. Can anyone find what I am doing wrong here?

Answer 1

Change

$dbh = new PDO("mysql:host=" . $config['host'] . ";dbname=" . $config['dbname'], $config['dbuser'], $config['dbpass']);

to

$this->dbh = new PDO("mysql:host=" . $config['host'] . ";dbname=" . $config['dbname'], $config['dbuser'], $config['dbpass']);

Change

$stmt = $db->execute("INSERT INTO images (filename) VALUES (?)");
$stmt->bindParam(1, "hello world!");
$stmt->execute();

to

error_reporting(E_ALL);
$stmt = $db->dbh->prepare("INSERT INTO images (filename) VALUES (?)");
if (!$stmt) die ('prepare() failed!');
$h = "hello world!";
$rv = $stmt->bindParam(1, $h);
if (!$rv) die ('bindParam() failed!');
$rv = $stmt->execute();
if (!$rv) die ('execute() failed!');

Answer 2

Try this:

index.php

<?php
error_reporting(E_ALL); 
ini_set('display_errors', 1);
require('includes/classes.php');
require_once('includes/config.php');

$db = new DatabaseCon();
$db = $db->dbConnect($config);

$stmt = $db->prepare("INSERT INTO images (filename) VALUES (?)");
$stmt->bindParam(1, "hello world!");
$stmt->execute();
?>

classes.php

<?php
error_reporting(E_ALL);
ini_set('display_errors', 1);
require('config.php');

// Connect to database
// Does not handle anything else
class DatabaseCon {

    // Method to connect to database
    function dbConnect($config) {
        try {
            $dbh = new PDO("mysql:host=" . $config['host'] . ";dbname=" . $config['dbname'], $config['dbuser'], $config['dbpass']);
            //$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT);
            return $dbh;
        } catch (PDOException $e) {
            echo $e->getMessage();
                    return false;
        }

    }
}

The DatabaseCon should be acting as a factory to create your connection object.

Answer 3

Thanks to the help of @BenRowe, I found the issue and it is now fixed. A combination of using the $this keyword, and removing the "hello world!" portion from the call to bindParam() fixed it. Seems that the bindParam() method only takes a value based on reference. So I set a random variable $h to "hello world!," and changed bindParam(1, "hello world") to bindParam(1, $h).

Thanks everyone :)