title: show related articles by title and tag using php/mysql
body: <p>I have an articles and tag tables like this</p>
  
  <pre><code> 1. articles
  |itemid   |title            |tag
  1         |my first post    |hello, world
  2         |my second        |world war post
  3         |my third post    |testing
  
  the tag is separate either by space or comma
  
  2. tagterm
  tag_id| tagterm
  1     | hello
  2     | world
  3     | war
  4     | post
  5     | testing
  
  
  3. tag_link
  id| tag_id| tag_itemid
  1 | 1     | 1
  2 | 2     | 1
  3 | 2     | 2
  and so on 
  </code></pre>
  
  <p>i would like to show all related articles by the tag field and also title if thats possible</p>
  
  <p>what i tried so far... does not work please help, im a newbie</p>
  
  <pre><code>SELECT a1.itemid, GROUP_CONCAT(DISTINCT a2.itemid) AS related_articles 
  FROM articles AS a1 
  JOIN tag_link AS t1 ON a1.itemid = t1.tag_itemid 
  JOIN articles AS a2 ON a2.itemid = t1.tag_itemid GROUP BY a1.itemid
  </code></pre>