一个交叉表SQL查询句子的分析

DecisionQuery里的一条语句
SELECT ORDERS.PaymentMethod, "ORDERS.DB".ShipVIA, "ORDERS.DB".Terms, "ORDERS.DB".ShipDate, COUNT( "ORDERS.DB".AmountPaid ), SUM( "ORDERS.DB".AmountPaid ), COUNT( "ORDERS.DB".ItemsTotal )
FROM "ORDERS.DB" ORDERS
GROUP BY ORDERS.PaymentMethod, "ORDERS.DB".ShipVIA, "ORDERS.DB".Terms, "ORDERS.DB".ShipDate

放在这里分析一下