Who knows how to fix?

Вылезла такая ошибка: Fatal error: Cannot redeclare get_singles_all() (previously declared in C:\OSPanel\domains\web\DB\db.php:12) in C:\OSPanel\domains\web\DB\db.php on line 15


<?php

$dbhost = "localhost";
$dbname = "test_saneto";
$username = "root";
$password = "";

$db = new PDO("mysql:host=$dbhost; dbname=$dbname", $username, $password);

// Получение всех статей
function get_singles_all(){
global $db;
$singles = $db->query("SELECT * FROM singles ORDER BY id DESC");
return $singles;
}

// Получение статьи по ее id
function get_single_by_id($id){
global $db;
$singles = $db->query("SELECT * FROM singles WHERE id = $id");
foreach($singles as $single){
return $single;
}
}

// Получение названия категории
function get_category_by_id($id){
global $db;
$categories = $db->query("SELECT * FROM categories WHERE id = $id");
}

// Получение имен авторов
function get_authors_by_id($id){
global $db;
$authors = $db->query("SELECT * FROM authors WHERE id = $id");
foreach($authors as $author){
return $author["author_name"];
}
}

// Получение комментариев
function get_comments_all(){
global $db;
$comments = $db->query("SELECT * FROM comments");
return $comments;
}

// Получение комментариев по id
function get_comments_all_by_id($id){
global $db;
$comments = $db->query("SELECT * FROM comments WHERE id_comment = $id");
foreach($comments as $comment){
return $comment["comment_text"];
}
}