No Recorded Discharge Date | Dataford Interview Questions

Your question is No Recorded Discharge Date. Start with the requirements and the one table on the right.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Providence data analysts need to identify patients who remain open in an encounter extract because no discharge date has been recorded. Write a PostgreSQL query using the patient_encounters table.

Requirements

Return each patient with a missing discharge_date, including the patient ID, name, admission date, and care unit.
Sort the results by earliest admission date first, then by patient ID.

A missing discharge date is represented by SQL NULL. Do not treat an empty string or a future discharge date as missing.

Schema

patient_encounters

Column	Type	Description
encounter_idPK	INTEGER	Unique encounter identifier
patient_id	INTEGER	Unique patient identifier
patient_name	VARCHAR(100)	Patient's display name
admission_date	DATE	Date the encounter began
discharge_date	DATE	Date of discharge, or NULL when not recorded
care_unit	VARCHAR(80)	Providence care unit for the encounter