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Window Functions in SQL
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Window Functions in SQL

MediumSQL · PostgreSQL

Problem

Tell me about a window function query you have written or debugged.

Using the provided tables, write a PostgreSQL query that returns the latest review for every employee, including employees who have no reviews. If an employee has multiple reviews on the latest date, select the review with the greatest review ID.

Output

  1. One row per employee, ordered by employee_id ascending.
  2. Columns: employee_id, employee_name, department, review_id, review_date, and rating.
  3. Employees without reviews must remain in the result with NULL review fields.

Schema

employees
ColumnTypeDescription
employee_idPKINTUnique employee identifier
employee_nameVARCHAR(100)Employee display name
departmentVARCHAR(100)Employee department
employee_reviews
ColumnTypeDescription
review_idPKINTUnique review identifier
employee_idINTEmployee receiving the review
review_dateDATEDate the review was recorded
ratingINTReview rating from 0 to 5
review_statusVARCHAR(30)Review workflow status
Tablesemployeesemployee_reviews
Interviewer

Your question is Window Functions in SQL. Start with the requirements and the two tables in the Question tab.

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

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CodePostgreSQL
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