1070. Product Sales Analysis III
SQL 50 · Sorting and Grouping (day 4). Decode it with the hints, solve it on LeetCode, then compare with the reference solution in MySQLPostgreSQL.
Your work
Hints
Open one at a time. Try to finish with as few as you can.
1. What does one output row represent?
One sale in its product’s first year.
2. Approach
WHERE (product_id, year) IN (SELECT product_id, MIN(year) … GROUP BY product_id).
3. The trap
A product can have several sales in its first year; keep them all.
Reference solution
Tested on MySQL 8.0 and PostgreSQL 16. Switch dialect at the top of the page.
Show the MySQLPostgreSQL solution
SELECT product_id, year AS first_year, quantity, price
FROM Sales
WHERE (product_id, year) IN (
SELECT product_id, MIN(year)
FROM Sales
GROUP BY product_id
);