Connecting to database with PDO in php

Question

I've written this small class for my database connections in my project:

 <?php
    class DatabaseUtility{

        private $dsn, $username, $password, $database, $pdo;

        public function __construct($host = 'localhost', $username = 'root', $password = '', $database){
            $this->dsn = "mysqli:dbname=$database;host:$host";
            $this->username = $username;
            $this->password = $password;
            $this->database = $database;
        }

        public function connect(){
            try{
                $this->pdo = new PDO($this->dsn,$this->username,$this->password,null);
                $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
                $this->pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
            } catch(PDOException $err){
                die($err->getMessage());
            }
        }

        public function prepareStatment($query){
            $this->pdo->prepare($query);
        }

    }
?>

And this is how i'm using it:

<?php
    require 'DatabaseUtility.php';
    $db = new DatabaseUtility('localhost','root','','apex');
    $db->connect();
    $statment = $db->prepareStatment("Select offer_id from offer_images where img_id = :img_id");

?>

But i'm getting the following error:

Could not find driver

I'm new to PDO stuff so please do guide me what i'm doing wrong? Is this method okay for a secure and fast database activity?

Update: I'm now using these lines of code to use my DatabaseUtility class but got an error:

 <?php
        require 'DatabaseUtility.php';
        $id= 25;
        $db = new DatabaseUtility('localhost','root','','apex');
        $db->connect();
        $statment = $db->prepareStatment("Select offer_id from offer_images where img_id = :img_id");
       $statment->bindParam("img_id", $id ,PDO::PARAM_INT);
        $statment->execute();
        print_r($statment);
    ?>

Error is:

call to a member function bindParam() on a non-object in this line:
$statment->bindParam("img_id", $id ,PDO::PARAM_INT);

Answer 1

So it seems like you're mixing MYSQL as database with the MYSQL API's in PHP eg PDO , mysqli_* or mysql_* .

You use PDO as API to connect to your MYSQL database. But you have a few little errors in your connection string:

                        //vvvvv < -- > vvvvvvvvv
$this->dsn = "mysqli:host=$host;dbname:$database";
                 //^ ^^^^ < - > ^^^^^^^ must be a equal sign
                 //| Your database is MYSQL so remove the i

Answer 2

It looks like you are not returning anything in your prepareStatment() method.

public function prepareStatment($query){
    return $this->pdo->prepare($query);
}

This is the reason $statment = $db->prepareStatment("Select offer_id from offer_images where img_id = :img_id"); was returning false.