db.php

<?php 
$pdoOptions = [
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
    PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"
];
$pdo = new PDO('mysql:host=127.0.0.1;dbname=blog', 'root', '', $pdoOptions);
$statement = $pdo->prepare("SELECT * FROM posts");
$statement->execute();
$posts = $statement->fetchAll(PDO::FETCH_ASSOC);