ocp 11g考試題庫(kù)詳解：1Z0-051-112題，完整題庫(kù)請(qǐng)點(diǎn)擊這里聯(lián)系老師咨詢了解

112. View the Exhibit and examine the structure of the PROMOTIONS table.

Evaluate the following SQL statement:

SQL>SELECT promo_category, AVG(promo_cost) Avg_Cost, AVG(promo_cost)*.25 Avg_Overhead

FROM promotions

WHERE UPPER(promo_category) IN ('TV', 'INTERNET','POST')

GROUP BY Avg_Cost

ORDER BY Avg_Overhead;

The above query generates an error on execution.

Which clause in the above SQL statement causes the error?

A. WHERE

B. SELECT

C. GROUP BY

D. ORDER BY

Answer: C

試題解析：

group by不能跟列別名