See the Exhibit and Examine the structure of SALES and PROMOTIONS tables: Exhibit:
You want to delete rows from the SALES table, where the PROMO_NAME column in the
PROMOTIONS table has either blowout sale or everyday low price as values. Which
DELETE statements are valid? (Choose all that apply.)
A.
DELETE FROM sales WHERE promo_id = (SELECT promo_id FROM promotions
WHERE promo_name = ‘blowout sale’) AND promo_id = (SELECT promo_id FROM
promotions WHERE promo_name = ‘everyday low price’);
B.
DELETE FROM sales WHERE promo_id = (SELECT promo_id FROM promotions
WHERE promo_name = ‘blowout sale’) OR promo_id = (SELECT promo_id FROM
promotions WHERE promo_name = ‘everyday low price’);
C.
DELETE FROM sales WHERE promo_id IN (SELECT promo_id FROM promotions
WHERE promo_name = ‘blowout sale’ OR promo_name = ‘everyday low price’);
D.
D DELETE FROM sales WHERE promo_id IN (SELECT promo_id FROM promotions
WHERE promo_name IN (‘blowout sale’,’everyday low price’));
“B” is very fragile. If the sub query will return more than 1 result the query will crash.