BookStore数据库中有销售明细表OrderDetail(OrderCode,BookCode,Amount)查询销售总量前20%的图书,并按总销量降序排列。SQL语句:SELECT TOP 20 PERCENT Bookcode As书号,SUM(Amount)As总销量ROMOrderDetail GROUP BY Book code ORDER BY()
A、AmountDESC
B、SUM(Amount)DESC
C、COUNT(Amount)DESC
D、ADD(Amount)DESC