LeetCode - 1045. Customers Who Bought All Products (MySQL)

Medium, SQL - GROUP BY, HAVING

RunTime : 468 ms

문제

Write a solution to report the customer ids from the Customer table that bought all the products in the Product table.

Return the result table in any order.

The result format is in the following example.

풀이

• 생각보다 매우 간단했던 문제
• 개수 비교를 통해 해결할 수 있다.

SELECT customer_id FROM Customer
GROUP BY 1
HAVING COUNT(DISTINCT product_key) = (
    SELECT COUNT(product_key) FROM Product
)