<?php

$query = "SELECT allergen_num, count(*) AS num FROM allergies WHERE school_num = $school_num GROUP BY 1";
$results = db_query($query);
while ($row = db_fetch_assoc($results)) {
   extract($row);
   if (isset($allergen_num) && intval($allergen_num) > 0) {
      $query = "UPDATE allergens SET member_count = $num WHERE school_num = $school_num AND record_num = $allergen_num";
      db_query($query);
   }
}
?>