Customers With Complete Product Coverage

Medium

You are given two relational tables. Customer captures purchase events: customer_id product_key Product captures the full catalog: product_key A customer is considered fully covered if they have purchased every product listed in Product at least once. Task: Return all qualifying customer_id values. Output one row per qualifying customer. Sort results by customer_id ascending. Supported submission environments: SQL (SQLite 3.27.2) Pandas (Python)

Example 1

Input

Customer:
| customer_id | product_key |
|-------------|-------------|
| 1           | 5           |
| 2           | 6           |
| 3           | 5           |
| 3           | 6           |
| 1           | 6           |

Product:
| product_key |
|-------------|
| 5           |
| 6           |

Output

[
  {"customer_id":1},
  {"customer_id":3}
]

Explanation

Customers 1 and 3 each purchased both required products.

Example 2

Input

Customer:
| customer_id | product_key |
|-------------|-------------|
| 10          | 100         |
| 10          | 100         |
| 11          | 100         |
| 11          | 101         |

Product:
| product_key |
|-------------|
| 100         |
| 101         |

Output

[
  {"customer_id":11}
]

Explanation

Duplicates for customer 10 do not compensate for missing product 101.

Example 3

Input

Customer:
| customer_id | product_key |
|-------------|-------------|
| 7           | 1           |
| 8           | 2           |

Product:
| product_key |
|-------------|
| 1           |
| 2           |

Output

[]

Explanation

No customer covers the entire catalog.

Constraints

1 <= number of rows in Product <= 200
1 <= number of rows in Customer <= 10,000
1 <= customer_id <= 1,000,000,000
1 <= product_key <= 1,000,000,000
Product.product_key is unique
Customer may contain duplicate (customer_id, product_key) rows
For SQL submissions, use SQLite 3.27.2 semantics
For Pandas submissions, return a DataFrame with one column: customer_id

Customer: | customer_id | product_key | |-------------|-------------| | 1 | 5 | | 2 | 6 | | 3 | 5 | | 3 | 6 | | 1 | 6 | Product: | product_key | |-------------| | 5 | | 6 |

Customer: | customer_id | product_key | |-------------|-------------| | 10 | 100 | | 10 | 100 | | 11 | 100 | | 11 | 101 | Product: | product_key | |-------------| | 100 | | 101 |

Customer: | customer_id | product_key | |-------------|-------------| | 7 | 1 | | 8 | 2 | Product: | product_key | |-------------| | 1 | | 2 |