Customers Who Bought All Products SQL MySQL leetcode Solution using having
Challenge: Finding Customers Who Bought Everything
Difficulty: Medium
Data:
Two tables store information about customer purchases:
Customer (Primary Key: customer_id):
customer_id (int): Unique identifier for a customer.
product_key (int): Foreign key referencing the Product table (product purchased).
Product (Primary Key: product_key):
product_key (int): Unique identifier for a product.
Objective:
Identify customer IDs from the Customer table who have purchased all products listed in the Product table.
Output:
A table with a single column:
customer_id (int): Unique identifier for a customer who bought all products (same as input table).
Explanation:
We need to find customer_id values in the Customer table where the distinct count of product_key matches the total number of unique products in the Product table. This indicates customers who purchased every product.
SQL MYSQL leetcode Solution with HAVING and DISTINCT COUNT