title: MySQL: Multiple Primary Keys and Auto Increment
body: <p>I'm quite new to setting up tables in MySQL and there is something I'd like to do which is a bit more advance than I'm able to do.</p>
  
  <p>I have two columns as part of a composite primary key, one is a Date and  an ID I would like to be an auto increment integer. For each date, I would like to reset the auto integer to 0, so something like this:</p>
  
  <pre><code>|-----------------|
  |Date       | ID  |
  |-----------------|
  |2012-06-18 | 1   |
  |2012-06-18 | 2   |
  |2012-06-18 | 3   |
  |2012-06-19 | 1   |
  |2012-06-19 | 2   |
  |2012-06-20 | 1   |
  |-----------------|
  </code></pre>
  
  <p>Thanks</p>