PHP/MYSQL: showing data out 2 databases : This is my first question and I tried to make it clear enough so you quys/girls can understand it. If I am missing something or doing something wrong please let me know! Its my first question.

**What I want:**

I want it to show the `voornaam` out of the database `Klanten` to show next to the other ones out of the database.

**What I have tried:**

    <?php
         $onderrwerp = $app->get_onderwerpen();
         $klantten = $app->get_klanten();
         foreach($onderrwerp as $onderwerp and $klantten as $klant){
           echo '<div class="well well-sm">';
           echo '<a href="https://tom.lbmedia.nl/reactie">' . $onderwerp['voornaam'].'</a>';
           echo '<h3>'.$onderwerp['naam'].'</h3><br>'; 
           echo '<a href="https://tom.lbmedia.nl/reactie">'  .$onderwerp['naam'].'</a>';
           echo '</div>';
        }
        ?>

**The php code:**

	<?php
     $onderrwerp = $app->get_onderwerpen();
     foreach($onderrwerp as $onderwerp){
       echo '<div class="well well-sm">';
       echo '<h3>'.$onderwerp['naam'].'</h3><br>'; 
       echo '<a href="https://tom.lbmedia.nl/reactie">'  .$onderwerp['naam'].'</a>';
       echo '</div>';
    }
    ?>

[How it looks like with this code][1]


**The functions:**

    public function get_onderwerpen(){
            $getOnderwerp = $this->database->query("SELECT * FROM onderwerpen ORDER BY id ASC");
            $onderwerpen = $this->database->resultset();
            
            return $onderwerpen;
            
       }
    public function get_klanten(){
            $getKlant = $this->database->query("SELECT * FROM klanten ORDER BY punten DESC");
            $klanten = $this->database->resultset();
            
            return $klanten;
            
        }


  [1]: https://i.stack.imgur.com/H5Kgu.png