Find Duplicate Records in SQL

EasySQL · PostgreSQL00:00

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Your question is Find Duplicate Records in SQL. Start with the requirements and the one table on the right.

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Problem

Johns Hopkins Medicine needs to identify duplicate patient records before a data quality cleanup. Write a SQL query to find records that appear more than once based on the same first_name, last_name, and date_of_birth.

Requirements

Return each duplicated name and birth date combination only once
Include the number of times each duplicate appears
Sort results by duplicate count descending, then by name

Schema

patient_records

Column	Type	Description
patient_idPK	INT	Primary key for each patient record
first_name	VARCHAR(100)	Patient first name
last_name	VARCHAR(100)	Patient last name
date_of_birth	DATE	Patient date of birth
mrn	VARCHAR(20)	Medical record number
created_at	TIMESTAMP	Record creation timestamp

Tablespatient_records

Your solutionPostgreSQL

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