Top Diagnoses SQL | Dataford Interview Questions

Write a SQL query to find the top five most common diagnoses in a given dataset. Use the provided diagnosis records and diagnosis reference data, excluding records without a recognized diagnosis.

Output

One row per diagnosis, with diagnosis_code, diagnosis_name, and diagnosis_count
Return only the five diagnoses with the highest counts
Sort by count descending, then diagnosis code ascending to break ties

Schema

diagnosis_records

Column	Type	Description
record_idPK	INT	Unique diagnosis record identifier
patient_id	INT	Identifier of the associated patient
diagnosis_code	VARCHAR(10)	Recorded diagnosis code
recorded_date	DATE	Date the diagnosis was recorded

diagnoses

Column	Type	Description
diagnosis_codePK	VARCHAR(10)	Reference diagnosis code
diagnosis_name	VARCHAR(150)	Readable diagnosis name

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