Watch 10 video solutions for Customers With Strictly Increasing Purchases, a hard level problem involving Database. This walkthrough by NeetCode has 427,733 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Table: Orders
+--------------+------+ | Column Name | Type | +--------------+------+ | order_id | int | | customer_id | int | | order_date | date | | price | int | +--------------+------+ order_id is the column with unique values for this table. Each row contains the id of an order, the id of customer that ordered it, the date of the order, and its price.
Write a solution to report the IDs of the customers with the total purchases strictly increasing yearly.
0.Return the result table in any order.
The result format is in the following example.
Example 1:
Input: Orders table: +----------+-------------+------------+-------+ | order_id | customer_id | order_date | price | +----------+-------------+------------+-------+ | 1 | 1 | 2019-07-01 | 1100 | | 2 | 1 | 2019-11-01 | 1200 | | 3 | 1 | 2020-05-26 | 3000 | | 4 | 1 | 2021-08-31 | 3100 | | 5 | 1 | 2022-12-07 | 4700 | | 6 | 2 | 2015-01-01 | 700 | | 7 | 2 | 2017-11-07 | 1000 | | 8 | 3 | 2017-01-01 | 900 | | 9 | 3 | 2018-11-07 | 900 | +----------+-------------+------------+-------+ Output: +-------------+ | customer_id | +-------------+ | 1 | +-------------+ Explanation: Customer 1: The first year is 2019 and the last year is 2022 - 2019: 1100 + 1200 = 2300 - 2020: 3000 - 2021: 3100 - 2022: 4700 We can see that the total purchases are strictly increasing yearly, so we include customer 1 in the answer. Customer 2: The first year is 2015 and the last year is 2017 - 2015: 700 - 2016: 0 - 2017: 1000 We do not include customer 2 in the answer because the total purchases are not strictly increasing. Note that customer 2 did not make any purchases in 2016. Customer 3: The first year is 2017, and the last year is 2018 - 2017: 900 - 2018: 900 We do not include customer 3 in the answer because the total purchases are not strictly increasing.