[SQL 문제 풀이] Product Sales Analysis I

Can you solve this real interview question? Product Sales Analysis I - Table: Sales +-------------+-------+ | Column Name | Type | +-------------+-------+ | sale_id | int | | product_id | int | | year | int | | quantity | int | | price | int | +-------------+-------+ (sale_id, year) is the primary key (combination of columns with unique values) of this table. product_id is a foreign key (reference column) to Product table. Each row of this table shows a sale on the product product_id in a certain year. Note that the price is per unit.   Table: Product +--------------+---------+ | Column Name | Type | +--------------+---------+ | product_id | int | | product_name | varchar | +--------------+---------+ product_id is the primary key (column with unique values) of this table. Each row of this table indicates the product name of each product.   Write a solution to report the product_name, year, and price for each sale_id in the Sales table. Return the resulting table in any order. The result format is in the following example.   Example 1: Input: Sales table: +---------+------------+------+----------+-------+ | sale_id | product_id | year | quantity | price | +---------+------------+------+----------+-------+ | 1 | 100 | 2008 | 10 | 5000 | | 2 | 100 | 2009 | 12 | 5000 | | 7 | 200 | 2011 | 15 | 9000 | +---------+------------+------+----------+-------+ Product table: +------------+--------------+ | product_id | product_name | +------------+--------------+ | 100 | Nokia | | 200 | Apple | | 300 | Samsung | +------------+--------------+ Output: +--------------+-------+-------+ | product_name | year | price | +--------------+-------+-------+ | Nokia | 2008 | 5000 | | Nokia | 2009 | 5000 | | Apple | 2011 | 9000 | +--------------+-------+-------+ Explanation: From sale_id = 1, we can conclude that Nokia was sold for 5000 in the year 2008. From sale_id = 2, we can conclude that Nokia was sold for 5000 in the year 2009. From sale_id = 7, we can conclude that Apple was sold for 9000 in the year 2011.