PHP - Why Is This Return Always 1

<?php

class Article{
    public function fetch_all(){
        global $pdo;

        $query = $pdo->prepare("SELECT * FROM `articles` ORDER BY `article_timestamp` DESC");
        $query->execute();

        return $query->fetchAll();
    }

    public function fetch_data($article_id){
        global $pdo;

        $query = $pdo->prepare("SELECT * FROM `articles` WHERE `article_id` = ?");
        $query->bindValue(1, $article_id);
        $query->execute();

        return $query->fetch();
    }

    /*
     * These have gotten added later on.
     */
    
    public function delete($id){
        global $pdo;

        $query = $pdo->prepare("DELETE FROM `articles` WHERE `article_id` = ?");
        $query->bindValue(1, $id);
        $query->execute();

        // The "return" here.

    }

    public function edit_page($title, $content, $aticle_id){
        global $pdo;

        $query = $pdo->prepare("UPDATE `articles` SET `article_title` = ?, `article_content` = ? WHERE `article_id` = ?");

        $query->bindValue(1, $title);
        $query->bindValue(2, $content);
        $query->bindValue(3, $article_id);

        $query->execute();

        // The "return" here.
    }

}


?>

Hi everyone

for my end of studies projects I decided to do a little e-commerce problem on the filter .. I use an ajax request at the click of the checkbox this goes to my controller which calls a method of my Model class but the concern is that .. if the array $ _POST ['brands'] has several elements then only the last one is returned to me? I thought I saw one day that if the same variable is in a url then the last value will be returned to me is for security but how can I do ... I have been there for too long .. and finally despair. . Help me please... :')

request payload:

brands%5B%5D=arai&brands%5B%5D=bell

reply :

<- prepare var_dump ()
object (PDOStatement) # 2 (1) {["queryString"] => string (73) "SELECT mark FROM articles WHERE categorie_article =? AND mark IN (?,?)"}

string (4) "arai" <- bind
string (4) "bell" <- bind

var_dump () of my fetchAll ()
array (2) {[0] => array (2) {["brand"] => string (4) "bell" [0] => string (4) "bell"} [1] => array (2 ) {["brand"] => string (4) "bell" [0] => string (4) "bell"}}
image_icon

since the last value taken into account is bell then I get two items of the bell brand from my bdd but no arai ...