Databases are universal - they underlie the technology you use every day. They're a crucial component of everything from telecommunications systems, banking systems, and video games to just about any other software system that maintains some amount of persistent data.

In this course, you'll learn about the fundamental concepts of databases, why and when they're used, what relational databases are, and entity-relationship diagrams. You will also be exposed to techniques like normalization that help to increase the efficiency of databases. You'll wrap up with a look at the basics of Structured Query Language (SQL). 

After completing this course, you will be able to move onto more advanced courses involving database systems and SQL.

Database Design Fundamentals for Software Engineers

# Relational database schemas

A relational database schema **S** is a set of relation schemas S = {R$_1$, R$_2$, … , R$_m$} and a set of integrity constraints **IC**. A relational database state **DB** of S is a set of relation states DB = {r$_1$, r$_2$, … , r$_m$} such that each r$_i$ is a state of R$_i$. 
The figure below shows a relational database schema that we call COMPANY = {EMPLOYEE, DEPARTMENT, DEPT_LOCATIONS, PROJECT, DEPENDENT}. In each relation schema, the underlined attribute represents the primary key.



In this lesson, we will discuss the basic concepts behind relational database schemas.

Introduction

Fundamental Concepts

Data Modeling

Entity-Relationship Data Model

The Relational Data Model

Functional Dependencies

Normalization

Structured Query Language

Conclusion

Relational Database Schemas

Relational database schemas