LeetCode 1158: Market Analysis I Solution

Master LeetCode problem 1158 (Market Analysis I), a medium challenge, with our optimized solutions in Java, C++, and Python. Explore detailed explanations, test your code in our interactive editor, and prepare for coding interviews.

1158. Market Analysis I

Medium

Database

Problem Explanation

Explanation

To solve this problem, we need to join the Users and Orders tables based on the buyer_id column. We can then filter the orders made in 2019 and count them for each user. Finally, we need to return the user_id, join_date, and the number of orders made in 2019 for each user.

Perform a left join on Users and Orders tables based on the buyer_id.
Filter the orders made in 2019.
Group the results by buyer_id.
Count the number of orders for each user.
Return the user_id, join_date, and the count of orders made in 2019.

Time Complexity: O(n) Space Complexity: O(n)

Solution Code

# Write your Java solution here
SELECT u.user_id AS buyer_id, u.join_date, COALESCE(COUNT(o.order_id), 0) AS orders_in_2019
FROM Users u
LEFT JOIN Orders o ON u.user_id = o.buyer_id
WHERE o.order_date >= '2019-01-01' AND o.order_date <= '2019-12-31' OR o.order_id IS NULL
GROUP BY u.user_id, u.join_date

Try It Yourself

Loading code editor...

Frequently Asked Questions

How to solve LeetCode 1158 (Market Analysis I)?

This page provides optimized solutions for LeetCode problem 1158 (Market Analysis I) in Java, C++, and Python, along with a detailed explanation and an interactive code editor to test your code.

What is the time complexity of LeetCode 1158 (Market Analysis I)?

The time complexity for LeetCode 1158 (Market Analysis I) varies by solution. Check the detailed explanation section for specific complexities in Java, C++, and Python implementations.

Can I run code for LeetCode 1158 on DevExCode?

Yes, DevExCode provides an interactive code editor where you can write, test, and run your code for LeetCode 1158 in Java, C++, or Python.

Back to LeetCode Solutions