Table: Product
+--------------+---------+
| Column Name | Type |
+--------------+---------+
| product_id | int |
| product_name | varchar |
| unit_price | int |
+--------------+---------+
product_id 是这个表的主键
Table: Sales
+-------------+---------+
| Column Name | Type |
+-------------+---------+
| seller_id | int |
| product_id | int |
| buyer_id | int |
| sale_date | date |
| quantity | int |
| price | int |
+------ ------+---------+
这个表没有主键，它可以有重复的行.
product_id 是 Product 表的外键.
编写一个SQL查询，报告2019年春季才售出的产品。即仅在2019-01-01至2019-03-31（含）之间出售的商品。
查询结果格式如下所示：
Product table:
+------------+--------------+------------+
| product_id | product_name | unit_price |
+------------+--------------+------------+
| 1 | S8 | 1000 |
| 2 | G4 | 800 |
| 3 | iPhone | 1400 |
+------------+--------------+------------+
Sales table:
+-----------+------------+----------+------------+----------+-------+
| seller_id | product_id | buyer_id | sale_date | quantity | price |
+-----------+------------+----------+------------+----------+-------+
| 1 | 1 | 1 | 2019-01-21 | 2 | 2000 |
| 1 | 2 | 2 | 2019-02-17 | 1 | 800 |
| 2 | 2 | 3 | 2019-06-02 | 1 | 800 |
| 3 | 3 | 4 | 2019-05-13 | 2 | 2800 |
+-----------+------------+----------+------------+----------+-------+
Result table:
+-------------+--------------+
| product_id | product_name |
+-------------+--------------+
| 1 | S8 |
+-------------+--------------+
id为1的产品仅在2019年春季销售，其他两个产品在之后销售。
思路：查出不符合要求的名单，判断每个商品是否在名单即可。
select product_id,product_name
from Product
where product_id not in (select product_id from Sales where sale_date>'2019-03-31' or sale_date<'2019-01-01');