Gain insights into fundamental database concepts, relational databases, and entity-relationship diagrams. Learn about normalization techniques and basics of SQL to enhance database efficiency.

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

# What is SQL?

SQL is Structured Query Language, which is a computer language for storing, manipulating and retrieving data in a relational database.

SQL is the standard language for a relational database system. All the Relational Database Management Systems (RDMS) like MySQL, MS Access, Oracle, and SQL Server use SQL as their standard database language.

# A brief history of SQL

SQL was initially developed by IBM in the early 1970s. The initial version, called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM’s quasi-relational database management system, System R. Then, in the late 1970s, Relational Software Inc., which is now Oracle Corporation, introduced the first commercially available implementation of SQL, Oracle V2 for VAX computers.

# Why SQL?

SQL is widely popular because it can

* Create the database and table structures.

* Perform basic data management chores (add, delete and modify).

* Perform complex queries to transform raw data into useful information.

# SQL Commands

The standard SQL commands to interact with relational databases are **CREATE**, **INSERT**, **UPDATE**, **DELETE**, and **DROP**. These commands can be classified into the following groups based on their nature:

**DDL - Data Definition Language**

|  Command  |   Description      |
| --- | ---  |
| **CREATE** | Creates a new table, a view of a table, or other objects in the database.    |
| **ALTER** | Modifies an existing database object, such as a table.  |
|  **DROP**  |  Deletes an entire table, a view of a table or other objects in the database.   |



**DML - Data Manipulation Language**

|  Command |  Description     |
| --- | --- |
| **INSERT**   |   Creates a record. |
| **UPDATE**  |    Modifies records.  |
| **DELETE**  |   Deletes records.  |


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In the next lesson, we will highlight some important data types and operations in SQL.

Introduction

Fundamental Concepts

Data Modeling

Entity-Relationship Data Model

The Relational Data Model

Functional Dependencies

Normalization

Structured Query Language

Conclusion

Structured Query Language (SQL)

What is SQL?