That just means MySQL insists that you give the inner SELECT a name, like: SELECT MAX(counted) FROM (     SELECT COUNT(*) AS counted     FROM table_actions     WHERE status = "good"     GROUP BY user ) AS counts;

If you have a dinamic website and want to allow your visitors to use the back button after they sent a form with the post method, the best combination I found was: <?php header("Expires: Sat, 01 Jan 2000 00:00:00 GMT"); header("Last-Modified: ".gmdate("D, d M Y H:i:s")." GMT"); header("Cache-Control: post-check=0, pre-check=0",false); session_cache_limiter("must-revalidate"); // and after you start the sessionsession_start(); ?> I try some combinations using header("Cache-Control: no-cache, must-revalidate"), but when clicking the back button, the last changes in the form back to their previous states. The combination above works fine with IE 6.x. I didn't test this with other browsers. When I try something like session_cache_limiter("nocache, must-revalidate") it doesn't work. The page only updates when I used the browser's refresh button. In dynamic web sites this is not g

You can reset the counter with: ALTER TABLE tablename AUTO_INCREMENT = 1 For InnoDB you cannot set the auto_increment value lower or equal to the highest current index