1327-ListProductsOrderedInPeriod.sql

/*
    Write a solution to get the names of products that have at least 100 units ordered in February 2020 and their amount.
    Return the result table in any order.

    Example 1:
    Input: 
    Products table:
    +-------------+-----------------------+------------------+
    | product_id  | product_name          | product_category |
    +-------------+-----------------------+------------------+
    | 1           | Leetcode Solutions    | Book             |
    | 2           | Jewels of Stringology | Book             |
    | 3           | HP                    | Laptop           |
    | 4           | Lenovo                | Laptop           |
    | 5           | Leetcode Kit          | T-shirt          |
    +-------------+-----------------------+------------------+
    Orders table:
    +--------------+--------------+----------+
    | product_id   | order_date   | unit     |
    +--------------+--------------+----------+
    | 1            | 2020-02-05   | 60       |
    | 1            | 2020-02-10   | 70       |
    | 2            | 2020-01-18   | 30       |
    | 2            | 2020-02-11   | 80       |
    | 3            | 2020-02-17   | 2        |
    | 3            | 2020-02-24   | 3        |
    | 4            | 2020-03-01   | 20       |
    | 4            | 2020-03-04   | 30       |
    | 4            | 2020-03-04   | 60       |
    | 5            | 2020-02-25   | 50       |
    | 5            | 2020-02-27   | 50       |
    | 5            | 2020-03-01   | 50       |
    +--------------+--------------+----------+
    Output: 
    +--------------------+---------+
    | product_name       | unit    |
    +--------------------+---------+
    | Leetcode Solutions | 130     |
    | Leetcode Kit       | 100     |
    +--------------------+---------+
*/

SELECT p.product_name, sum(o.unit) AS unit
FROM Products p
JOIN Orders o
ON p.product_id = o.product_id
WHERE o.order_date>='2020-02-01' and o.order_date<='2020-02-29'
GROUP BY o.product_id 
HAVING unit >= 100