150.View the Exhibit and examine the data in the PROMOTIONS table.
A.SELECT promo_category FROM promotions
MINUS
SELECT promo_category FROM promotions
WHERE promo_subcategory = 'discount';
B.SELECT promo_category FROM promotions
INTERSECT
SELECT promo_category FROM promotions
WHERE promo_subcategory = 'discount';
C.SELECT promo_category FROM promotions
MINUS
SELECT promo_category FROM promotions
WHERE promo_subcategory <> 'discount';
D.SELECT promo_category FROM promotions
INTERSECT
SELECT promo_category FROM promotions
WHERE promo_subcategory <> 'discount';
答案:AD
解析:这里考察的是INTERSECT和MINUS
INTERSECT:获取a表和b表的交集
MINUS:获取a表中排除b表数据的集合
题目说的是不包含discount的数据,那么
A:正确,总的数据减去包含discount的数据,剩下的也就是不包含的数据了
B:错误,总的数据与包含discount的数据的交集,也就是包含discount的数据
C:错误,总的数据减去不包含discount的数据,剩下的也就是包含的数据了
D:正确,总的数据与不包含discount的数据的交集,也就是不包含discount的数据
You need to display all promo categories that do not have 'discount' in their subcategory.
A.SELECT promo_category FROM promotions
MINUS
SELECT promo_category FROM promotions
WHERE promo_subcategory = 'discount';
B.SELECT promo_category FROM promotions
INTERSECT
SELECT promo_category FROM promotions
WHERE promo_subcategory = 'discount';
C.SELECT promo_category FROM promotions
MINUS
SELECT promo_category FROM promotions
WHERE promo_subcategory <> 'discount';
D.SELECT promo_category FROM promotions
INTERSECT
SELECT promo_category FROM promotions
WHERE promo_subcategory <> 'discount';
答案:AD
解析:这里考察的是INTERSECT和MINUS
INTERSECT:获取a表和b表的交集
MINUS:获取a表中排除b表数据的集合
题目说的是不包含discount的数据,那么
A:正确,总的数据减去包含discount的数据,剩下的也就是不包含的数据了
B:错误,总的数据与包含discount的数据的交集,也就是包含discount的数据
C:错误,总的数据减去不包含discount的数据,剩下的也就是包含的数据了
D:正确,总的数据与不包含discount的数据的交集,也就是不包含discount的数据