Problem
Table: Product
+---------------+---------+ | Column Name | Type | +---------------+---------+ | product_id | int | | product_name | varchar | +---------------+---------+ product_id is the primary key (column with unique values) for this table. product_name is the name of the product.
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Table: Sales
+---------------------+---------+ | Column Name | Type | +---------------------+---------+ | product_id | int | | period_start | date | | period_end | date | | average_daily_sales | int | +---------------------+---------+ product_id is the primary key (column with unique values) for this table. period_start and period_end indicate the start and end date for the sales period, and both dates are inclusive. The average_daily_sales column holds the average daily sales amount of the items for the period. The dates of the sales years are between 2018 to 2020.
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Write a solution to report the total sales amount of each item for each year, with corresponding product_name
, product_id
, report_year
, and total_amount
.
Return the result table ordered by product_id
and report_year
.
The result format is in the following example.
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Example 1:
Input: Product table: +------------+--------------+ | product_id | product_name | +------------+--------------+ | 1 | LC Phone | | 2 | LC T-Shirt | | 3 | LC Keychain | +------------+--------------+ Sales table: +------------+--------------+-------------+---------------------+ | product_id | period_start | period_end | average_daily_sales | +------------+--------------+-------------+---------------------+ | 1 | 2019-01-25 | 2019-02-28 | 100 | | 2 | 2018-12-01 | 2020-01-01 | 10 | | 3 | 2019-12-01 | 2020-01-31 | 1 | +------------+--------------+-------------+---------------------+ Output: +------------+--------------+-------------+--------------+ | product_id | product_name | report_year | total_amount | +------------+--------------+-------------+--------------+ | 1 | LC Phone | 2019 | 3500 | | 2 | LC T-Shirt | 2018 | 310 | | 2 | LC T-Shirt | 2019 | 3650 | | 2 | LC T-Shirt | 2020 | 10 | | 3 | LC Keychain | 2019 | 31 | | 3 | LC Keychain | 2020 | 31 | +------------+--------------+-------------+--------------+ Explanation: LC Phone was sold for the period of 2019-01-25 to 2019-02-28, and there are 35 days for this period. Total amount 35*100 = 3500. LC T-shirt was sold for the period of 2018-12-01 to 2020-01-01, and there are 31, 365, 1 days for years 2018, 2019 and 2020 respectively. LC Keychain was sold for the period of 2019-12-01 to 2020-01-31, and there are 31, 31 days for years 2019 and 2020 respectively.