SQL Challenge: Employee Salary Analytics

Lakshit

Consider an employees table:

• employee_id (int)
• employee_name (varchar)
• department (varchar)
• joining_date (date)
• salary (decimal)

1. Highest Earner by Department:
2. Find the employee with the highest salary in each department.
3. Average Salary by Department and Year:
4. Calculate the average salary for each department per year.
5. Longest Serving Employee:
6. Identify the employee with the longest tenure.

Please provide concise SQL queries for these analyses, emphasizing simplicity and efficiency. Thanks!