title: How to make multiple tables share the id column in MySQL
body: <p>This question has been asked before but never really answered (at least the way I want to do it). I have three tables in my database, <code>threads</code>, <code>responses</code> and <code>votes</code>. I need them to share the <code>id</code> field only. So I can do something like</p>
  
  <pre><code>SELECT * FROM threads AS t JOIN responses AS r JOIN votes AS v
  WHERE id = 15
  </code></pre>
  
  <p>and will only retrieve a thread a response or (exclusive) a vote record with id = 15.</p>
  
  <p>Is there a possible way to do this without creating an extra table? I'm not asking if it's a good idea (which is probably not), but if it's possible and how to do it.</p>