[LeetCode/SQL] 1045. Customers Who Bought All Products

[LeetCode/SQL]

---

📌 1045. Customers Who Bought All Products

문제

풀이

product 테이블에 있는 상품을 모두 구매한 
고객을 출력하라 

방법 I

SELECT customer_id
FROM Customer
GROUP BY customer_id
HAVING COUNT(distinct product_key)=(SELECT COUNT(product_key) FROM product)