title: difference between `id int(10)` and `id bigint(10)`
body: <p>I am creating a table for that I am using a integer primary key field
  I am creating table as</p>
  
  <pre><code>CREATE TABLE `post` (
   `id`  int(100) NOT NULL AUTO_INCREMENT,
   `description` varchar(100),
     PRIMARY KEY (`id`)
   );
  </code></pre>
  
  <p>I read this <a href="http://dev.mysql.com/doc/refman/5.0/en/numeric-types.html" rel="nofollow">Numeric Types</a>. according to this we can store values in int and bigint less than 20 digits.</p>
  
  <p>I would like to know about following </p>
  
  <ol>
  <li>What is the difference between <code>id  int(10)</code> and <code>id  bigint(10)</code></li>
  <li>I have used <code>id  int(100)</code> is there any problem.</li>
  <li>what data type should i use for above id(for id value 21 to 100
  digits).</li>
  </ol>