（149）View the Exhibits and examine the structures of the COSTS and PROMOTIONS tables. Evaluate the following SQL statement:

SELECT prod_id FROM costs

WHERE promo_id IN (SELECT promo_id FROM promotions WHERE promo_cost < ALL (SELECT MAX(promo_cost) FROM promotions

GROUP BY (promo_end_date - promo_begin_date)));

What would be the outcome of the above SQL statement?

A. It displays prod IDs in the promo with the lowest cost.

B. It displays prod IDs in the promos with the lowest cost in the same time interval.

C. It displays prod IDs in the promos with the highest cost in the same time interval.

D. It displays prod IDs in the promos with cost less than the highest cost in the same time interval.

答案：（D）

解析：

注意ALL后面的子查询中只有一个值

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OCP 1Z0 051 149