title: MySQL sub-SELECT from same table
body: <p>This is oversimplified for the purpose of this question, but suppose I have an <code>INVENTORY</code> table with the following columns: <code>SKU</code>, <code>DATE</code>, <code>QUANTITY</code>.  I want to select all of the columns where the <code>QUANTITY</code> from the day previous is less than the <code>QUANTITY</code> for any day.  How do you write a <code>SELECT</code> query with a sub <code>SELECT</code> on the same table?</p>
  
  <p>Or, if anyone knows what to call this kind of query so I can do more research on my own that would be helpful.  (ie., Is this a recursive query?)</p>