SQL Subqueries

Background

Subqueries nest one query inside another, enabling complex filtering and computation based on query results.

Problem

Write a SQL query to find employees who earn more than the average salary of their department using a correlated subquery.

Input

An employees table with id, name, department, salary columns.

Output

Employees earning above their department average salary.

Sample tests

Input: employees across 3 departments with varying salaries

Expected: employees above their dept average

Your solution

Learning objective

Learn correlated subqueries, subquery in WHERE, and performance considerations.