Write an SQL query to display Employee Name, Department Name, and Salary, and another query to find the third highest salary from the Employee table.

To display the employee name, department name, and salary, you need to join the Employee and Department tables on dept_id. The query is:

SELECT e.emp_name, d.dept_name, e.salary

FROM Employee e

JOIN Department d ON e.dept_id = d.dept_id;

For the third highest salary, you can use a subquery that orders distinct salaries in descending order and limits the result to the third row. One concise way is:

SELECT DISTINCT salary

FROM Employee

ORDER BY salary DESC

LIMIT 1 OFFSET 2;

Alternatively, you can use a window function to rank salaries and then filter for rank = 3:

SELECT salary

FROM (

SELECT salary, DENSE_RANK() OVER (ORDER BY salary DESC) AS rnk

FROM Employee

) AS ranked

WHERE rnk = 3;

Both approaches run in O(n log n) time due to the sort, and they handle duplicate salaries correctly by using DISTINCT or DENSE_RANK().