Using PDO database class within other PHP classes

Question

I have a database class that uses PDO. Here\'s a portion example of it:

class db {
private $host;
private $username;
private $password;
private $con;
    pri         


        

Answer 1

Take a look into the Singleton Design Pattern, it works great for a DB class

I used to use a class like this for quite a while

   abstract class DB
   {

    protected static $instance;

    protected $db;

    protected static $host = 'host';
    protected static $user = 'user';
    protected static $pass = 'pass';
    protected static $database;

    public static function getInstance()
    {
        if (!isset(self::$instance)) self::$instance = new static();

        return self::$instance;
    }

    protected function __construct()
    {
        $this->db = new PDO(sprintf('mysql:host=%s;dbname=%s', static::$host, static::$database), static::$user, static::$pass);
        $this->db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    }

    public static function db()
    {
        return static::getInstance()->db;
    }

    public function fetch_single_row($sql, $data)
    {
        if( $data !== null )
            $data = array_values( $data ); // Incase it's an associative array
        $sel = self::db()->prepare( $sql );
        $sel->execute( $data );
        $sel->setFetchMode( PDO::FETCH_OBJ );
        $obj = $sel->fetch();
        return $obj;
    }
}

I would then extend that class for each different database I would need to connect to

class Main extends DB
{
    protected static $database = 'db';
}

You can then use the class like this

$db = Main::getInstance();
$obj = $db->fetch_single_row($sql, $data);