查询搜索＃按升序向上，而不是从数据库中获取实际代码

I have a query fetching product ID from the database, then base on the ID #, I have a switch statement that gets the image for the product. All works fine and at the end of the switch I have a default case where it would just print out an image that says "no image available".

Here is part of the code for imagequery.php

<?php
if($image = mysqli_fetch_assoc($imagequery))
{
  switch($image['product_code'])
  {
case 0:
  echo '<th><img src="Images/pencil.jpg">';
  break;
case 1:
  echo '<th><img src="Images/pen.jpg">';
  break;
case 2:
  echo '<th><img src="Images/marker.png">';
  break;
case 3:
  echo '<th><img src="Images/clipper.png">';
  break;
case 4:
  echo '<th><img src="Images/paper.png">';
  break;
default:
  echo '<th><img src="Images/noimage.jpg">';
  break;
  }
}

Edit1: After doing more recommended echo checks, turns out the $image['imagequery'] is going in ascending order and I'm not sure why. My code to get $imagequery is this.

    $results = "SELECT product_code FROM products WHERE product_desc='Office Materials'";
    $imagequery = mysqli_query($mysqli, $results);
    include('imagequery.php');