1084\. Sales Analysis III

Easy

SQL Schema

Table: `Product`

    +--------------+---------+
    | Column Name  | Type    |
    +--------------+---------+
    | product_id   | int     |
    | product_name | varchar |
    | unit_price   | int     |
    +--------------+---------+
    product_id is the primary key of this table.
    Each row of this table indicates the name and the price of each product. 

Table: `Sales`

    +-------------+---------+
    | Column Name | Type    |
    +-------------+---------+
    | seller_id   | int     |
    | product_id  | int     |
    | buyer_id    | int     |
    | sale_date   | date    |
    | quantity    | int     |
    | price       | int     |
    +-------------+---------+
    This table has no primary key, it can have repeated rows.
    product_id is a foreign key to the Product table.
    Each row of this table contains some information about one sale. 

Write an SQL query that reports the **products** that were **only** sold in the first quarter of `2019`. That is, between `2019-01-01` and `2019-03-31` inclusive.

Return the result table in **any order**.

The query result format is in the following example.

**Example 1:**

**Input:**

    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  |
    +-----------+------------+----------+------------+----------+-------+

**Output:**

    +-------------+--------------+
    | product_id  | product_name |
    +-------------+--------------+
    | 1           | S8           |
    +-------------+--------------+

**Explanation:**

The product with id 1 was only sold in the spring of 2019.

The product with id 2 was sold in the spring of 2019 but was also sold after the spring of 2019.

The product with id 3 was sold after spring 2019.

We return only product 1 as it is the product that was only sold in the spring of 2019. 
