SQL Data Validation Checks | Dataford Interview Questions

How would you implement a data validation check in SQL?

Validate each record for a nonblank record key, an allowed status, an event date in 2025, and a non-null amount that is zero or greater. Return every record, including valid records, and identify all applicable validation issues.

Output

One row per record with record_id, record_key, validation_status, and validation_errors.
Set validation_status to VALID or INVALID; combine multiple issues in validation_errors.
Order by record_id ascending.

Schema

validation_records

Column	Type	Description
record_idPK	INT	Unique identifier for the record
record_key	VARCHAR(40)	Business key that should be present and nonblank
status_code	VARCHAR(20)	Status that must exist in the allowed-status reference table
event_date	DATE	Date required to fall within calendar year 2025
amount	NUMERIC(10,2)	Value that must be non-null and non-negative

allowed_statuses

Column	Type	Description
status_codePK	VARCHAR(20)	Recognized status code
status_label	VARCHAR(60)	Description of the recognized status

Your question is SQL Data Validation Checks. Start with the requirements and the two tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem