Customers With Net-Positive Revenue in 2021

EASY10 pts

A subscription analytics team stores customer-level annual revenue snapshots and needs a clean list of accounts that ended 2021 above break-even.

Table: customers

customer_id: unique customer identifier
year: fiscal year of the snapshot
revenue: net revenue for that customer in that year

Data guarantees:

(customer_id, year) is unique.
revenue may be negative, zero, or positive.

Task: Return all customer_id values that satisfy both conditions:

year = 2021
revenue > 0

Output requirements:

Return exactly one column in this order:
- customer_id
Sort results by customer_id in ascending order.

Supported submission environments:

SQL (SQLite 3.27.2)
Pandas (Python)

Example

Input

customers:
| customer_id | year | revenue |
|-------------|------|---------|
| 1           | 2018 | 50      |
| 1           | 2021 | 30      |
| 1           | 2020 | 70      |
| 2           | 2021 | -50     |
| 3           | 2018 | 10      |
| 3           | 2016 | 50      |
| 4           | 2021 | 20      |

Output

[
  {"customer_id":1},
  {"customer_id":4}
]

Explanation

Customers 1 and 4 have strictly positive revenue in 2021. Customer 2 is negative in 2021, and customer 3 has no 2021 row.

Example

Input

customers:
| customer_id | year | revenue |
|-------------|------|---------|
| 11          | 2019 | 8       |
| 12          | 2022 | 90      |
| 13          | 2020 | -2      |

Output

[]

Explanation

No row meets year=2021 and revenue>0 simultaneously.

Example

Input

customers:
| customer_id | year | revenue |
|-------------|------|---------|
| 40          | 2021 | 0       |
| 41          | 2021 | 300     |
| 42          | 2021 | -1      |
| 43          | 2017 | 1000    |

Output

[
  {"customer_id":41}
]

Explanation

Revenue must be strictly greater than zero in 2021. Zero and negative values are excluded, and positive values in other years do not qualify.

Accepted0/0·0% Acceptance

Constraints

0 <= number of rows in customers <= 250000
1 <= customer_id <= 1000000000
2000 <= year <= 2030
-1000000000 <= revenue <= 1000000000
(customer_id, year) is unique
Return exactly one column: customer_id
Sort results by customer_id ascending
For SQL submissions, use SQLite 3.27.2 semantics
For Pandas submissions, return a DataFrame with column: customer_id

Code

Visualizer

Solutions

14px

Test Cases3

Results

Submissions

customers =

[{"customer_id":1,"year":2018,"revenue":50},{"customer_id":1,"year":2021,"revenue":30},{"customer_id":1,"year":2020,"revenue":70},{"customer_id":2,"year":2021,"revenue":-50},{"customer_id":3,"year":2018,"revenue":10},{"customer_id":3,"year":2016,"revenue":50},{"customer_id":4,"year":2021,"revenue":20}]

Customers With Net-Positive Revenue in 2021

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Customers With Net-Positive Revenue in 2021

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