Optimizing MySQL Queries for Finding Top Earners by Department (leetcode : 184. Department Highest Salary)
Optimizing MySQL Queries for Finding Top Earners by Department Optimizing MySQL Queries for Finding Top Earners by Department In this blog post, we’ll explore how to write and optimize a MySQL query to find employees with the highest salary in each department. This is a common problem in database querying, often encountered in interviews and real-world applications. We’ll compare two solutions: one using a correlated subquery and an optimized version using a Common Table Expression (CTE). We’ll explain the approach, logic, time complexity, and provide the complete SQL code for both. Problem Statement Given two tables: Employee : Contains employee details with columns id , name , salary , and departmentId . Department : Contains department details with columns id and name . We need to find each employee who earns the highest salary in their department, returning the department name, employee name, and salary....