title: Insert md5 hash into mysql database
body: <p>I'm trying to insert a md5 hash into a mysql database table with php.</p>
  
  <pre><code>        $key = $email . date('mY');
          $key = md5($key);
  
          $query = "INSERT INTO confirm (key, angemeldet_von, geschlecht, geburtstag)
              VALUES('$key', '$angemeldet_von', '$geschlecht', '$geburtstag')";
          $confirm = mysql_query($query, $connectionID)
            or die('failed connecting: ' . mysql_error());
  </code></pre>
  
  <p>This query returns the error:</p>
  
  <pre><code>failed connecting: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'key, angemeldet_von, geschlecht, geburtstag) VALUES('8fe3ec75be1a43b49eacd3' at line 1
  </code></pre>
  
  <p>But the same query works well when I leave out the key column and its value.
  So what is the problem here?
  Mysql:</p>
  
  <pre><code>key varchar(128)    utf8_general_ci
  </code></pre>