How to avoid opening multiple connections to the DB with OOP PHP

Question

I\'ve been a procedural programmer for over 4 yrs and it\'s time to start looking into OOP. With that said, let\'s say I needed to call two methods in my class. Each method requ

Answer 1

you should use singleton pattern

EDIT: the way you did it, it is possible to call _connect multiple times, which means reconnecting.

singleton implementation usually means you have to make constructor private/protected and define a getInstance method which creates connection on first call and returns the created connection on later calls.

this is what i would do:

class Database_Conn extends Model {

    static protected $_instance;

    protected $db = null;

    final protected function __construct() {
        $m = new Mongo("localhost:27017", array("persist"=>"x"));
        $this->db = $m->selectDB( "foo" );
    }

    static public function getInstance() {
        if (!(self::$_instance instanceof self)) {
            self::$_instance = new self();
        }
        return self::$_instance;
    }

    public function getConnection() {
        return $this->db;
    }

    final protected function __clone() { }
}

and then use Database_Conn::getInstance()->getConnection() to get the connection object.