Nth Highest Salary
You can write a SQL query to get the nth highest salary from the Employee table using a subquery and the LIMIT
and OFFSET
clauses. Here’s how you can do it:


This code creates a function that selects the unique salaries from the Employee table, orders them in descending order, and then uses the LIMIT
and OFFSET
clauses to get the nth highest salary. If there is no nth highest salary, the variable nthHighestSalary
will remain NULL, and the function will return NULL.
The reason for using N  1
in the OFFSET clause is related to how SQL numbering and the requirement for the “nth highest salary” work.
In SQL, OFFSET starts at 0, not 1. So, when you want to retrieve the 1st highest salary, you would use an OFFSET of 0. For the 2nd highest salary, you would use an OFFSET of 1, and so on.
So, the formula N  1
converts the humanreadable “nth” term into the zerobased numbering that SQL expects for the OFFSET.
 If you want the 1st highest salary, N is 1, so
N  1
gives you an OFFSET of 0.  If you want the 2nd highest salary, N is 2, so
N  1
gives you an OFFSET of 1.  And so on.
This allows you to skip over the first N  1
highest salaries and return the Nth one.