title: combine multiple queries on same mysql table
body: <p>I'm trying to connect each answer in this table with the title to its question. I understand that nested queries are a bad idea. Is there another way to do this?</p>
  
  <pre><code>postid | type     | parent_postid | title       | content
  ----------------------------------------------------
  1      | question | NULL          | car wheels  | how many
  2      | answer   | 1             | NUll        | 4 wheels
  
  SELECT * FROM table WHERE type = 'answer'
  
  while($row = mysql_fetch_array($result)) {
      $parent_postid = row['parent_postid'];
      SELECT title FROM table WHERE postid = '$parent_postid'
  }
  </code></pre>