title: mysql show databases() only information_schema database
body: <p>I use <code>mysql -u root -p</code> to login to mysql. Command <code>show databases</code> only shows information_schema database, and <code>current_user</code> is not root</p>
  
  <pre><code>mysql&gt; show databases;
  +--------------------+
  | Database           |
  +--------------------+
  | information_schema |
  +--------------------+
  2 rows in set (0.00 sec)
  
  mysql&gt; select current_user();
  +----------------+
  | current_user() |
  +----------------+
  | @localhost     |
  +----------------+
  1 row in set (0.00 sec)
  </code></pre>