047 第141题 请教
141. View the Exhibit and examine the descriptions for ORDERS and ORDER_ITEMS tables.
Evaluate the following SQL statement:
SELECT o.customer_id, oi.product_id, SUM(oi.unit_price*oi.quantity) "Order Amount"
FROM order_items oi JOIN orders o
ON oi.order_id = o.order_id
GROUP BY CUBE (o.customer_id, oi.product_id);
Which three statements are true regarding the output of this SQL statement? (Choose three.)
A. It would return the subtotals for the Order Amount of every CUSTOMER_ID.
B. It would return the subtotals for the Order Amount for every PRODUCT_ID.
C. It would return the subtotals for the Order Amount of every PRODUCT_ID and CUSTOMER_ID as one
group.
D. It would return the subtotals for the Order Amount of every CUSTOMER_ID and PRODUCT_ID as one
group.
E. It would return only the grand total for the Order Amount of every CUSTOMER_ID and PRODUCT_ID
as one group.
Answer: ABD
c和d感觉是一样的啊,还是我理解有误。。。