如何从mySQL数据库中获取时间戳？

Question

my query won't show a timestamp if i call the function getDate_created();. how can i fix this? The function getAll() does work.

<?php

class Post
{
    public $date_created;


    public function getDate_created()
    {
        return $this->date_created;
    }

    public function setDate_created($date_created)
    {
        $this->date_created = $date_created;

        return $this;
    }

    public static function getAll()
    {
        $conn = Db::getInstance();
        $result = $conn->query('SELECT * FROM images');

        return $result->fetchAll(PDO::FETCH_CLASS, __CLASS__);
     }
 }


$posts = Post::getAll();

$timepost = new Post();
$t = $timepost->getDate_created();
var_dump($t);

the table images:

CREATE TABLE `images` (
   `id` int(11) NOT NULL,
   `user_id` int(11) NOT NULL,
   `img_description` varchar(255) NOT NULL,
   `date_created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
   `file_path` varchar(255) NOT NULL
   ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

Var_dump($t) shows NULL as result.

Answer 1

You are creating a new instance of Post when you do $timepost = new Post();

If you want to read one of those posts from database you should read one (or more) from those that came from getAll() method.

Ex:

$posts = Post::getAll();

foreach($posts as $post) {
    var_dump($post->getDate_created());
}

//or

var_dump($posts[0]->getDate_created());