Clase Abstracta PHP - PDO

<?php

abstract class ClsABSDataBase {

    private static $host = "localhost";
    private static $user = "root";
    private static $pass = "";
    protected $db = "nombre_basededatos";
    private $conex;
    protected $query;
    protected $data = array();
    protected $result = array();

    abstract protected function get($query, $data);

    abstract protected function set($query, $data);

    abstract protected function edit($query, $data);

    private function conDB($db = '') {
        try {
            $this->db = ($db != '') ? $db : $this->db;
            $this->conex = new PDO("mysql:host=" . self::$host . ";dbname=$this->db", self::$user, self::$pass);
            $this->conex->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        } catch (PDOException $ex) {
            die("Error SQL [" . $ex->getCode() . "] " . $ex->getMessage());
        }
    }

    private function desconDB() {
        try {
            $this->conex = null;
        } catch (PDOException $ex) {
            die("Error SQL [" . $ex->getCode() . "] " . $ex->getMessage());
        }
    }

    protected function getResult() {
        try {
            $this->conDB();
            $eSql = $this->conex->prepare($this->query);
            $eSql->execute($this->data);

            $this->result = $eSql->fetchAll(PDO::FETCH_ASSOC);
            $this->desconDB();
        } catch (PDOException $ex) {
            die("Error SQL [" . $ex->getCode() . "] " . $ex->getMessage());
        }
    }

    protected function query() {
        try {
            $this->conDB();
            $eSql = $this->conex->prepare($this->query);
            $eSql->execute();
            $this->desconDB();
        } catch (PDOException $ex) {
            die(md_err($ex->getCode(), $ex->getMessage(), "Error SQL"));
        }
    }
}