title: Showing year over year results in SQL
body: <p>I've searched and tried some variations on things I found but am getting stumped on something I feel should be easy.</p>
  
  <p>Example data includes:</p>
  
  <pre>LOCATION,  SALES, MONTH, YEAR
  Location1, 100,   4,     2012
  Location1, 130,   4,     2013</pre>
  
  <p>I'm trying to write a Select statement that will allow me to show the sales from the previous month/year against the current month/year.</p>
  
  <p>The results would, ideally, look like:</p>
  
  <pre>LOCATION, [4/2012 Sales], [4/2013 Sales]
  Location1, 100, 130</pre>
  
  <p>Any help is appreciated.</p>