ocp题库解析：11g-1Z0-051-第18题
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ocp题库解析：11g-1Z0-051-第18题，完整题库请点击这里联系老师咨询了解
18. Examine the structure of the PROMOTIONS table:
name Null Type
PROMO_ID NOT NULL NUMBER(6)
PROMO_NAME NOT NULL VARCHAR2(30)
PROMO_CATEGORY NOT NULL VARCHAR2(30)
PROMO_COST NOT NULL NUMBER(10,2)
The management wants to see a report of unique promotion costs in each promotion category.
Which query would achieve the required result?
A. SELECT DISTINCT promo_cost, promo_category FROM promotions;
B. SELECT promo_category, DISTINCT promo_cost FROM promotions;
C. SELECT DISTINCT promo_cost, DISTINCT promo_category FROM promotions;
D. SELECT DISTINCT promo_category, promo_cost FROM promotions ORDER BY 1;
A与描述的不一致
BC语法错误，DISTINCT放在第二列要报错。
此题答案选D
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