00:00:00

Description

Editorial

Customers Without Purchase Activity

EASY10 pts

Your commerce analytics team maintains two relational tables:

Customers: master customer records with id and name
Orders: checkout events with order id and customerId

Build a report that returns every customer who has never placed an order.

Output requirements:

Return exactly one column named Customers.
Include customer names where Customers.id does not appear in Orders.customerId.
Return rows in any order unless your local checker requires deterministic sorting.

This problem must be solved for:

SQL (SQLite 3.27.2)
Pandas

Example

Input

Customers:
| id | name  |
|----|-------|
| 1  | Joe   |
| 2  | Henry |
| 3  | Sam   |
| 4  | Max   |

Orders:
| id | customerId |
|----|------------|
| 1  | 3          |
| 2  | 1          |

Output

[
  {"Customers":"Henry"},
  {"Customers":"Max"}
]

Explanation

Customers 2 and 4 do not appear in Orders.customerId, so they are returned.

Example

Input

Customers:
| id | name  |
|----|-------|
| 10 | Ana   |
| 11 | Omar  |

Orders:
| id | customerId |
|----|------------|
| 90 | 10         |
| 91 | 10         |

Output

[
  {"Customers":"Omar"}
]

Explanation

Multiple orders from the same customer still mean that customer is active. Only customer 11 has no order.

Example

Input

Customers:
| id | name   |
|----|--------|
| 7  | Priya  |
| 8  | Arjun  |

Orders:
| id | customerId |
|----|------------|
| 1  | null       |
| 2  | 8          |

Output

[
  {"Customers":"Priya"}
]

Explanation

A null customerId in Orders does not match any customer. Only customer 8 has a valid order reference.

Accepted0/0·0% Acceptance

Constraints

1 <= number of rows in Customers <= 10,000
0 <= number of rows in Orders <= 10,000
Customers.id is unique
Orders.id is unique
Orders.customerId may include IDs not present in Customers (or null in imperfect data feeds)
Use SQLite 3.27.2 semantics for SQL submissions
For Pandas submissions, return a DataFrame with exactly one column: Customers

Code

Visualizer

Solutions

14px

Test Cases3

Results

Submissions

orders =

[{"id":1,"customerId":3},{"id":2,"customerId":1}]

customers =

[{"id":1,"name":"Joe"},{"id":2,"name":"Henry"},{"id":3,"name":"Sam"},{"id":4,"name":"Max"}]

Loading problem...

101

00:00:00

Description

Editorial

Customers Without Purchase Activity

EASY10 pts

Your commerce analytics team maintains two relational tables:

Customers: master customer records with id and name
Orders: checkout events with order id and customerId

Build a report that returns every customer who has never placed an order.

Output requirements:

Return exactly one column named Customers.
Include customer names where Customers.id does not appear in Orders.customerId.
Return rows in any order unless your local checker requires deterministic sorting.

This problem must be solved for:

SQL (SQLite 3.27.2)
Pandas

Example

Input

Customers:
| id | name  |
|----|-------|
| 1  | Joe   |
| 2  | Henry |
| 3  | Sam   |
| 4  | Max   |

Orders:
| id | customerId |
|----|------------|
| 1  | 3          |
| 2  | 1          |

Output

[
  {"Customers":"Henry"},
  {"Customers":"Max"}
]

Explanation

Customers 2 and 4 do not appear in Orders.customerId, so they are returned.

Example

Input

Customers:
| id | name  |
|----|-------|
| 10 | Ana   |
| 11 | Omar  |

Orders:
| id | customerId |
|----|------------|
| 90 | 10         |
| 91 | 10         |

Output

[
  {"Customers":"Omar"}
]

Explanation

Multiple orders from the same customer still mean that customer is active. Only customer 11 has no order.

Example

Input

Customers:
| id | name   |
|----|--------|
| 7  | Priya  |
| 8  | Arjun  |

Orders:
| id | customerId |
|----|------------|
| 1  | null       |
| 2  | 8          |

Output

[
  {"Customers":"Priya"}
]

Explanation

A null customerId in Orders does not match any customer. Only customer 8 has a valid order reference.

Accepted0/0·0% Acceptance

Constraints

1 <= number of rows in Customers <= 10,000
0 <= number of rows in Orders <= 10,000
Customers.id is unique
Orders.id is unique
Orders.customerId may include IDs not present in Customers (or null in imperfect data feeds)
Use SQLite 3.27.2 semantics for SQL submissions
For Pandas submissions, return a DataFrame with exactly one column: Customers

Code

Visualizer

Solutions

14px

Test Cases3

Results

Submissions

orders =

[{"id":1,"customerId":3},{"id":2,"customerId":1}]

customers =

[{"id":1,"name":"Joe"},{"id":2,"name":"Henry"},{"id":3,"name":"Sam"},{"id":4,"name":"Max"}]

Customers Without Purchase Activity

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Customers Without Purchase Activity

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