   [web] Imposing Limits on MySql Averaging
  Question:If I want to take the average over a column in a mysql database....  but, I only want to average the last 10 or so entries, how would I go about setting this condition?  My attempt was to do it like this:  "Select avg(Column1) from Table order by Column2 desc limit 0, 10"But, it failed pretty miserably... and after looking at it, I can understand why.  I know I could run two queries, thus changing my statment to:  "Select avg(Column1) from Table where Column2 > X"   But.. that requires I figure out what X is (which requires a second query).  Any ideas on how I could reduce this down to 1 call?   