Forward-Fill NULL Job Roles

SQLMediumMid level~15 min

Problem

**[Classic — asked at multiple analytics companies]**

An employee log records role changes; NULL means no change that period.
Fill each NULL `job_role` with the **most recent non-NULL role** for that employee.

Return `employee_id`, `log_date`, and `filled_role`, ordered by employee then date.

Tables

Example rows — the live problem includes the full dataset.

employee_log

log_id	employee_id	log_date	job_role

Expected output

Your answer should return 7 rows with the columns employee_id, log_date, filled_role.

Starter code (SQL)

SELECT *
FROM employee_log;

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Solution & explanation

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