title: auto increment second column
body: <p>I have a table with 2 columns. The ID column auto increments. I'm trying to auto increment the user column with the same ID as the <code>id</code> column, but with a "user" prefix (example: user100, where the ID is also 100) basically just like what is done on stackoverflow.</p>
  
  <pre><code>CREATE TABLE test_table (
       id MEDIUMINT NOT NULL AUTO_INCREMENT,
       user CHAR(30) NOT NULL,
       PRIMARY KEY (id)
  ) ENGINE=MyISAM;
  </code></pre>
  
  <p>Is there a way of doing this in 1 query? Instead of inserting into the DB, then querying to get the ID, and inserting the ID into the user column?</p>