title: Modify select join to use one query instead of two
body: <p>Please consider the following query:</p>
  
  <pre><code>SELECT item.*, address_book.Country
  FROM item 
  INNER JOIN address_book
  ON item.addressbook_id=address_book.idaddress_book and address_book.Country="USA"  order by rand() limit 100;  ; 
  </code></pre>
  
  <p>What I would normally do after that is If I get no results to run another query without any restrictions on the country (so that I will get all the countries).</p>
  
  <p>If I get results but they are less than 100 I then rerun the second query for all the countries but with a limit (100-myexistingnoofresults)</p>
  
  <p>Is there any way to use only the first query and modify it somehow so the first x results to be USA (per the example) and the rest anything  and if no results for "USA" exist to display anything else.</p>
  
  <p>Also if possible I would like to display the results randomly.</p>