Grant all privileges to all users on a host in mysql
<p>How to grant all privileges to all users in mySQL ?</p>

<pre><code>GRANT ALL PRIVILEGES ON *.* TO 'USERNAME'@'1.2.3.4' IDENTIFIED BY 'PASSWORD' WITH GRANT OPTION;
</code></pre>

<p>What do I replace username with in order to allow it for every user on the given IP?Even if it is <code>''</code> i.e no username at all in input ?</p>

<p>I tried <code>*</code> and <code>%</code> in username but that did not help. </p>