API With Data Manipulation | Dataford Interview Questions

Describe an API you built that included some data manipulation.

For the SQL portion, write a query over the provided API tables to produce an endpoint-level report for January 2026. Include only POST, PUT, and PATCH requests in that month, while retaining endpoints with no matching requests.

Output

One row per endpoint, with route, http_method, request_count, mutation_count, total_rows_changed, and successful_request_count.
Count mutations and changed rows associated with included requests; count successful requests with status codes from 200 through 299.
Order by route, then http_method ascending.

Schema

api_endpoints

Column	Type	Description
endpoint_idPK	INTEGER	Unique endpoint identifier
route	VARCHAR(100)	API route path
http_method	VARCHAR(20)	Configured HTTP method

api_requests

Column	Type	Description
request_idPK	INTEGER	Unique API request identifier
endpoint_id	INTEGER	Referenced endpoint
http_method	VARCHAR(20)	Method used by the request
requested_at	TIMESTAMP	Request timestamp
status_code	INTEGER	HTTP response status code

api_mutations

Column	Type	Description
mutation_idPK	INTEGER	Unique mutation identifier
request_id	INTEGER	Request that caused the mutation
rows_changed	INTEGER	Number of rows changed by the mutation

Your question is API With Data Manipulation. Start with the requirements and the three tables in the Question tab.

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Problem