title: float precision problem in mysql
body: <p>Can anybody, given example below, make to me an explanation how FLOAT works in mySQL? I know that float is approximative, but really, such a difference? And there is only 9 digits, so it is not overflow problem, isn't it?</p>
  
  <pre><code>mysql&gt; create table t(f FLOAT(15,2), db DOUBLE);
  mysql&gt; insert into t(f,db) VALUES (512659663, 512659663);
  mysql&gt; select * from t;
  
  +--------------+-----------+
  | f            | db        |
  +--------------+-----------+
  | 512659648.00 | 512659663 |
  +--------------+-----------+
  </code></pre>
  
  <p>(mysql  Ver 14.14 Distrib 5.1.44, for Win32 (ia32) on Windows XP)</p>