Get to know tables
1. Introduction
OVER()
Computations with OVER()
Aggregate functions with OVER()
OVER() and WHERE
Summary

## Instruction

Hello! In the previous part, we showed you a very complicated query that might have looked a bit scary to you. In this part, we're going to start from the very beginning. Step by step, you will learn new elements that make up window functions. We hope that at the end of our course, you will take one more look at that scary example and think: this is now so easy!

But first things first. We'll start with introducing today's tables. We're going to deal with employees, their departments and purchases in each department. Not very original, you can find such tables in many database examples, but that's exactly the point – we want you to feel comfortable when you take your first steps with window functions.

## Exercise

Select all the information from table employee.

The table presents all employees at some point in time. Each employee has a first and last name, a department in which they work, their salary and the number of full years they have worked in the company so far.