title: PHP mysql search multiple tables using a keyword
body: <p>I have three tables in my database which are:</p>
  
  <pre><code>messages
  topics
  comments
  </code></pre>
  
  <p>Each of these tables has two fields called 'content' and 'title'. I want to be able to use 'Like' in my sql statement to look at 'messages.content', 'messages.title', 'topics.content', 'topics.title', 'comments.content' and 'comments.title' using a keyword.</p>
  
  <p>So far, my query is able to find results from only one table:</p>
  
  <pre><code>mysql_query("SELECT * FROM messages 
  WHERE content LIKE '%" . $keyword . "%' 
  OR title LIKE '%" . $keyword ."%'");
  </code></pre>
  
  <p>I am also wondering, once I get the results from multiple tables, how can I tell what result is from what table? </p>
  
  <p>Any help would be greatly appreciated!</p>