Identify Customers Purchasing Every Product in Catalog

X_PURCHASES

+-------------+---------+
| customer_id | pro_key |
+-------------+---------+
| 1           | A       |
| 1           | B       |
| 2           | A       |
+-------------+---------+

PRODUCT_CATALOG_Y

+---------+
| pro_key |
+---------+
| A       |
| B       |
+---------+

Scenario

E-commerce team wants to identify customers who have purchased every product currently in the catalog.

Question

Using SQL (or Python), return the customer_id values who have at least one purchase in X_PURCHASES for every pro_key that appears in PRODUCT_CATALOG_Y.

Hints

Group by customer and compare counts, or use NOT EXISTS to filter missing products.

Customers who purchased all catalog products

You are given two tables: X_PURCHASES, which records product purchases by customers, and PRODUCT_CATALOG_Y, which lists all products currently in the catalog. Using SQL, return the customer_id values for customers who have at least one purchase in X_PURCHASES for every pro_key that appears in PRODUCT_CATALOG_Y.

Table X_PURCHASES

column	type	constraints
customer_id	INTEGER
pro_key	VARCHAR(10)

Sample data:

customer_id	pro_key
1	A
1	B
2	A

Table PRODUCT_CATALOG_Y

column	type	constraints
pro_key	VARCHAR(10)

Sample data:

pro_key
A
B

Expected output

Return one row per customer_id where the customer has purchased all products listed in PRODUCT_CATALOG_Y at least once.

customer_id
1

Hints

1. Join purchases to the product catalog and group by customer_id.
2. In the HAVING clause, compare the count of distinct purchased products to the total count of products in PRODUCT_CATALOG_Y.
3. Alternatively, use NOT EXISTS to filter out customers missing any catalog product.