[PHP-DB] Difference between 2 dates.. thoughts?

[Aaron Wolski]

Hi All,
 
First off I have a query like this:
 
SELECT dateinserted FROM SiteTrackingTable;
 
Now. in this query any number of results could be returned 10 or 1000,
etc.
 
Is it possible to take the dateinserted value from the first record and
then from the last record and perform some calculation to get the number
of days the record spans?
 
Haven't done something like this before and don't have a clue where to
start. Date sorting,etc I can do just don't know about this one.
 
Thanks for your help!
 
Aaron