UNION Two Tables and Deduplicate | Dataford Interview Questions

Novo Nordisk's analytics team is consolidating patient records from Wegovy and Ozempic clinical programs. Write a PostgreSQL query that combines both patient tables and removes duplicate records.

Requirements

Return patient_id, patient_name, birth_date, and indication from both tables.
Use UNION so identical rows are returned only once. Do not treat records with the same patient_id but different attributes as duplicates.
Sort the final result by patient_id, then indication.

Schema

wegovy_program_patients

Column	Type	Description
patient_id	INTEGER	Patient identifier
patient_name	VARCHAR(100)	Patient name
birth_date	DATE	Patient date of birth
indication	VARCHAR(80)	Clinical indication

ozempic_program_patients

Column	Type	Description
patient_id	INTEGER	Patient identifier
patient_name	VARCHAR(100)	Patient name
birth_date	DATE	Patient date of birth
indication	VARCHAR(80)	Clinical indication

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