PHP函数后不显示HTML

I have a page that will not show the bottom half of my HTML after my PHP Code. The only way I could get it to show was to place a RETURN at the end of the WHILE Loop, which also ended the loop. I know it is probably something simple and just need to find out what it is. Thanks in advance for your help.

The HTML:

<table border='0'>
 <thead>
     <tr>
        <th scope="cols">Select</th>
        <th scope="cols">Name</th>
        <th scope="cols">Units</th>
        <th scope="cols">Amounts</th>
        <th scope="cols">Calories</th>
        <th scope="cols">Sugars</th>
   </tr>
 </thead>
 <tbody>
    <?php 
         //Establishs the DB connection
         $sql = new Mysql();

         //Queries the Foods
         $sql->food();
      ?> <!--NOTHING SHOWS FROM HERE DOWN-->
  </tbody>    
</table>
<h2>Training Plan</h2>
<table id="dairy">
 <thead>
     <tr>
        <th scope="cols">Select</th>
        <th scope="cols">Name</th>
        <th scope="cols">Units</th>
        <th scope="cols">Amounts</th>
        <th scope="cols">Calories</th>
        <th scope="cols">Sugars</th>
     </tr>
     ...more HTML....

The PHP Function:

function food() {
   //Query's the DB
   $result = $this->conn->query("SELECT * FROM ingredient")  or die(mysql_error());

   //Display's all of the Contents in the DB
   while ($row = $result->fetch_assoc() or die(mysql_error()))
   {
       echo'<tr class="normal" id="row'.$row['id'].'" onclick="onRow(this.id);">'."
\t\t\t\t\t\t\t".'<td><input type="checkbox" value="'.$row['id'].'" id="checkbox" /></td>'."
\t\t\t\t\t\t\t";
       echo'<td>'.$row['Name'].'</td>'."
\t\t\t\t\t\t\t";
       echo'<td>'.$row['Units'].'</td>'."
\t\t\t\t\t\t\t";
       echo'<td>'.$row['Amount'].'</td>'."
\t\t\t\t\t\t\t";
       echo'<td>'.$row['Calories'].'</td>'."
\t\t\t\t\t\t\t";
       echo'<td>'.$row['Sugar'].'</td>'."
\t\t\t\t\t\t";
       echo'</tr>'."
\t\t\t\t\t\t";
   }
}

while ($row = $result->fetch_assoc() or die(mysql_error()))

The problem is in this line, if $result->fetch_assoc() returns falsy when there are no more rows(which I suspect it does) you script will be stopped. Leave out the die part

while ($row = $result->fetch_assoc())

It's not showing because you have an error. Is food a member of the $sql class?