SQL: Deleting Duplicate Records | Dataford Interview Questions

How would you delete duplicate records in SQL?

Assume duplicate rows have identical values in record_key, record_value, and source_system. Keep the row with the smallest record_id and delete the remaining copies.

Output

Return one row per deleted record.
Include deleted_record_id.
Order results by deleted_record_id ascending.

Schema

records

Column	Type	Description
record_idPK	BIGINT	Unique identifier for the record
record_key	VARCHAR(50)	Business key used to identify the record
record_value	VARCHAR(100)	Value associated with the business key
source_system	VARCHAR(30)	System that created the record
created_at	TIMESTAMP	Timestamp when the record was created

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