PHP script not recognising my mysql query - php

Question

I am new to php and mysql and I have began coding a simple social media network. So I am currently working on my login.php page which seem to have no errors, but it is not working as it should and I am assuming it is because the query is not being recognised as a statement. i.e "password" should not be highlighted as a key word but it is a field in the database. I am also aware that I have not considered injection. When I run this in the browser there are no errors but it returns "User not registered" even when a user is in the database. Any insight would be great thanks!
Here is my code:
<?php
include('classes/DB.php');
if (isset($_POST['login'])) {
$username = $_POST['username'];
$password = $_POST['password'];
if (DB::query('SELECT username FROM users WHERE username=:username',
array(':username'=>$username))) {
if (password_verify($password, DB::query("SELECT password FROM
users WHERE username=:username", array(':username'=>$username))[0]
['password'])) {
echo 'Logged in!';
} else {
echo 'Incorrect Password!';
}
} else {
echo 'User not registered!';
}
}
Here is my DB.php class:
<?php
class DB {
private static function connect() {
$pdo = new PDO('mysql:host=127.0.0.1;dbname=SocialNetwork;charset=utf8', 'root', '');
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
return $pdo;
}
public static function query($query, $params = array()) {
$statement = self::connect()->prepare($query);
$statement->execute($params);
if (explode(' ', $query)[0] == 'SELECT') {
$data = $statement->fetchAll();
return $data;
}
}
}

Answer 1

<?php
include('classes/DB.php');
if (isset($_POST['login'])) {
$username = $_POST['username'];
$password = $_POST['password'];
if (DB::query('SELECT username FROM users WHERE username=:username',
array('username'=>$username))) {
if (password_verify($password, DB::query("SELECT password FROM
users WHERE username=:username", array('username'=>$username))[0]
['password'])) {
echo 'Logged in!';
} else {
echo 'Incorrect Password!';
}
} else {
echo 'User not registered!';
}
}