按类别显示数据顺序php

Question

我该如何显示

category1

id
title

category2

id
title

但直到现在只有我可以显示的是所有这些按类别排序。我的代码：

 $query = mysql_query("select * from article where user_id = '$userId' order by category,date desc") ; 
 while( $row = mysql_fetch_assoc( $query )) {
    $id=$row['id'];
    $trimstring = substr($row['body'], 0, 100) ;
    $varCategory = NULL;
        ?>
        <div class="container" id = "articles">
            <h1><a href="index.php?page=articol&id=<?php echo $id;?>"><?php echo $row['title'];?></a></h1>
            <p>  <?php echo $trimstring; ?> </p>
            <p id = "date">  <?php echo $row['date']; ?> </p>
        </div>

       <?php
         }