This displays information on total sales for all the authors. The SQL is quite tricky... I wonder if it is possible to have a breakdown of how many of each books...
Author Total Sales
Klaus Bohn151976310917.34
Blizzard Entertainment4252546813.7000003
,Kimberly Hartz6365.04
Anne J. Adelman1693.5
Sony Computer Entertainment144.78
Zed Shaw44.05



All content are being used for learning and practising SQL and PHP.