title: PDO Mysql Update query appears to execute twice?
body: <p>I have a script that runs an update query, yet it appears that the query is executing twice, as the value is incremented by double the number I give it each time (e.g. +2 adds 4 onto the value, +3 would add 6 onto the value). What am I doing wrong? Other questions of a similar nature here appear to have other flaws wrong with the code, but even if I keep it as simple as possible, it still appears to run the query twice. If I run it manually in MySQL, the query increments only once as expected.</p>
  
  <pre><code>&lt;?php
  $db = new PDO('mysql:host=localhost;dbname=db;charset=utf8', 'user', 'password', array(PDO::ATTR_EMULATE_PREPARES =&gt; false, PDO::ATTR_ERRMODE =&gt; PDO::ERRMODE_EXCEPTION));
  $query = $db-&gt;query("UPDATE basket SET quantity = (quantity + 1) WHERE user_id = 1 AND product_id = 4"); 
  $query-&gt;execute();
  die();
  ?&gt;
  </code></pre>