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

## The entity-relationship data model

The entity-relationship (ER) data model is a high-level conceptual data model that has existed for over 35 years. It is well suited to data modeling for use with databases because it is fairly abstract and is easy to discuss and explain. ER models, also called ER schemas, are represented by **ER diagrams**.

ER modeling is based on two concepts:

* **Entities**, defined as tables that hold specific information (data).

* **Relationships**, defined as the associations or interactions between entities.

Here is an example of how these two concepts might be combined in an ER data model: Prof. Lawrence (entity) teaches (relationship) the database systems course (entity).



# The entity-relationship data model

The entity-relationship (ER) data model is a high-level conceptual data model that has existed for over 35 years. It is well suited to data modeling for use with databases because it is fairly abstract and is easy to discuss and explain. ER models, also called ER schemas, are represented by **ER diagrams**.

ER modeling is based on two concepts:

* **Entities**, defined as tables that hold specific information (data).

* **Relationships**, defined as the associations or interactions between entities.

Here is an example of how these two concepts might be combined in an ER data model: Prof. Lawrence (entity) teaches (relationship) the database systems course (entity).



This lesson introduces the concept of entity-relationship model.

Introduction

Fundamental Concepts

Data Modeling

Entity-Relationship Data Model

The Relational Data Model

Functional Dependencies

Normalization

Structured Query Language

Conclusion

Intro to Entity-Relationship Model

The entity-relationship data model