OCP-1Z0-051-题目解析-第18题
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?
（ 题意：题目给出了一个PROMOTIONS表的结构，需要打印出每个促销品种中不同的促销价格的报表，问，下面哪条查询语句能够满足这个要求？）
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;
Answer: D
题目解析：这题和OCP-1Z0-051-题目解析-第14题是一样的都是考察distinct的使用。
A: 把promo_cost字段放在前面显然不合题意，题目要求是每个促销品种中的不同的价格都打印出来。
BC:语法错误。
D: 正确。
版权声明：本文为博主原创文章，未经博主允许不得转载。
页:
[1]