（112）View the Exhibit and examine the structure of the PROMOTIONS table. Evaluate the following SQL statement:

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

答案：（C）

解析：

group by子句中不允许出现别名

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OCP 1Z0-051-112