题目链接：点击打开链接
题目大意：略。
解题思路：略。
AC 代码
-- 解决方案(1)
SELECT DISTINCT t1.product_id, t1.product_name
FROM (SELECT s.product_id, product_name
FROM Product p JOIN Sales s ON s.product_id = p.product_id
WHERE sale_date BETWEEN '2019-01-01' AND '2019-03-31') t1
LEFT JOIN
(SELECT s.product_id, product_name
FROM Product p JOIN Sales s ON s.product_id = p.product_id
WHERE NOT(sale_date BETWEEN '2019-01-01' AND '2019-03-31')) t2
ON t1.product_id = t2.product_id
WHERE t2.product_id IS NULL
-- 解决方案(2)
SELECT s.product_id, product_name
FROM Sales s
JOIN Product p
ON s.product_id = p.product_id
GROUP BY s.product_id
HAVING MIN(sale_date) >= '2019-01-01' AND MAX(sale_date) <= '2019-03-31'
