title: PDO UPDATE creates a new record instead of updating one
body: <p>I'm using the following code to update a record. Bad thing is that it's not updating a record but it's adding a new record.</p>
  
  <p>What am I doing wrong? I want it to update the record and not create a now one. </p>
  
  <p>My modify url looks like this: <a href="http://randomsite.com/modify.php?id=1" rel="nofollow">http://randomsite.com/modify.php?id=1</a></p>
  
  <p><strong>Modify.php code:</strong></p>
  
  <pre><code>&lt;?php
      require_once("connect.php");
  
      $query = "SELECT * FROM cars WHERE id = :id";
  
      $result = $odb-&gt;prepare($query);
      $result-&gt;execute(array(':id' =&gt; $_REQUEST['id']) );
  
      while  ($row = $result-&gt;fetch(PDO::FETCH_ASSOC)) { ?&gt;
  
  
      &lt;h1&gt;Modify a car&lt;/h1&gt;
      &lt;form  action="&lt;?php echo $_SERVER['PHP_SELF']; ?&gt;" method="post"&gt;
      Brand:      &lt;input type="text" name="brand" value="&lt;?php echo $row['brand']; ?&gt;"  /&gt;&lt;br /&gt;
      Model:      &lt;input type="text" name="model" value="&lt;?php echo $row['model']; ?&gt;"  /&gt;&lt;br /&gt;
      Year:       &lt;input type="text" name="year"  value="&lt;?php echo $row['year'];  ?&gt;"   /&gt;&lt;br /&gt;
      ID:     &lt;input type="text" name="id"  value="&lt;?php echo $row['id'];  }?&gt;"   /&gt;&lt;br /&gt;
      &lt;input type="submit" value="Modify" /&gt;
      &lt;/form&gt;
  
      &lt;?php
  
      if(isset($_POST['submit'])) {
      $id    = $_POST['id'];
      $brand = $_POST['brand'];
      $model = $_POST['model'];
      $year  = $_POST['year'];
      $q     = "UPDATE cars WHERE id = $_GET[id] (id, brand, model, year) VALUES(:id, :brand, :model, :year)";
      $query = $odb-&gt;prepare($q);
      $results = $query-&gt;execute(array(
              ":id"    =&gt; $id,
              ":brand" =&gt; $brand,
              ":model" =&gt; $model,
              ":year"  =&gt; $year,
      )); 
  }
  ?&gt;
  </code></pre>