title: PHP / MySQL query. Select either the one or the other
body: <p>I was trying to select pretty specific data from the database but my query does not seem to work. Is this query correct?</p>
  
  <pre><code>SELECT * 
  FROM matches 
  WHERE compo_id = '1' 
      AND match_id &lt; '5' 
      AND clan_user_id_1 = '0' 
      OR clan_user_id_2 = '0'
  </code></pre>
  
  <p>So I want to select all matches where either clan_user_id_1 or clan_user_id_2 equals zero.</p>