Store sessions in DB (using using catfan/medoo)

schema.sql

CREATE TABLE IF NOT EXISTS sessions (
  id varchar(32) NOT NULL,
  access int(10) unsigned DEFAULT NULL,
  data text,
  PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

Session.php

<?php


class Session
{
    private $db = false;

    public function __construct()
    {
        $this->db = new \Medoo\Medoo(); // http://medoo.in

        session_set_save_handler(
            [$this, "_open"],
            [$this, "_close"],
            [$this, "_read"],
            [$this, "_write"],
            [$this, "_destroy"],
            [$this, "_gc"]
        );

        session_start(); // @?
    }

    public function _open()
    {
        if ($this->db !== false) {
            return true;
        }

        return false;
    }

    public function _close()
    {
        $this->db = null;

        return true;
    }

    public function _read($sessionID)
    {
        $row = $this->db->get('session', 'data', [
            'session_id' => $sessionID,
        ]);

        if ($row !== null) {
            return $row['data'];
        }

        return '';
    }

    public function _write($sessionID, $data)
    {
        // Create time stamp
        $access = time();

        $bool = $this->db->replace('session', [
            'access' => $access,
            'data' => $data,
        ], [
            'session_id' => $sessionID,
        ]);

        if ($bool !== false) {
            return true;
        }

        return false;
    }

    public function _destroy($sessionID)
    {
        $bool = $this->db->delete('session', [
            'session_id' => $sessionID,
        ]);

        if($bool !== false) {
            return true;
        }

        return false;
    }

    public function _gc($max)
    {
        $old = time() - $max;

        $bool = $this->db->delete('session', [
            'access[<]' => $old,
        ]);

        if ($bool !== false) {
            return true;
        }

        return false;

    }
}