SQL Remove Duplicate Rows | Dataford Interview Questions

Write a query to remove duplicate rows from a table while keeping the latest record.

Use records and treat rows with the same customer_id and event_type as duplicates. The latest row is determined by recorded_at, with record_id as the tie-breaker when timestamps match.

Output

Delete every duplicate while retaining one latest row per business key.
Return deleted record_id, customer_id, and event_type values.
Ordering is not required for the returned rows.

Schema

records

Column	Type	Description
record_idPK	INT	Unique record identifier
customer_id	INT	Customer associated with the event
event_type	VARCHAR(30)	Type of customer event
payload	TEXT	Event data stored with the record
recorded_at	TIMESTAMPTZ	Time when the event was recorded

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