View the Exhibit and examine the description of SALES and PROMOTIONS tables.
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’));
Wouldn’t B be incorrect? Both subqueries can return multiple rows, it would need “promo_id IN” instead of “promo_id =”