title: update specific bit in integer column
body: <p>I have a mysql table where user permissions are stored as a bitmask:</p>
  
  <pre><code>|user   | permissions |
  | Admin | 31          |
  | User  | 13          |
  
             16 8  4  2  1
  Admin -&gt;   1  1  1  1  1  -&gt; 16 + 8 + 4 + 2 + 1 -&gt; 31
  User  -&gt;   0  1  1  0  1  -&gt;  8 + 4 + 1 -&gt; 13
  </code></pre>
  
  <p>Now I want to add a permission for every user with an sql query.
  Let's say I want to add the permission 16 for everyone without modifying another bit.</p>
  
  <pre><code> UPDATE users SET permission = ????
  </code></pre>
  
  <p>How do I do this?</p>