Johansen - SQL The Ultimate Beginners Guide

SQL

The Ultimate Beginners Guide!

Andrew Johansen

Copyright 2015 by Andrew Johansen- All rights reserved.

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Table of Contents

Introduction

Chapter 1: SQL The Basics

Chapter 2: The SQL Commands That You Can Use

Chapter 3: Data Types

Chapter 4: How to Manage Database Objects

Chapter 5: Database Normalization

Chapter 6: Data Manipulation

Chapter 7: How to Manage Database Transactions

Chapter 8: How to Get Excellent Results from Database Queries

Chapter 9: Categorize Information Using Database Operators

Conclusion

Introduction

I want to thank you and congratulate you for getting my book

SQL: The Ultimate Beginners Guide!

This book will teach you the basics of SQL and database operations. Since SQL is a language used to manage databases, you have to familiarize yourself with its basics and nuances. Dont worry if you have never used SQL before: this book will turn you from a beginner to an efficient SQL-user.

This book will cover important topics about SQL. For instance, a chapter focuses on the operators that you can use. Another chapter, however, concentrates on giving you accurate results from your database queries. Overall, youll be an effective SQL user after reading this book.

Thanks again for getting a copy of this book, I hope you enjoy it!

Chapter 1: SQL The Basics

Every company generates, holds, and uses data. Thus, companies need an organized way of storing information. This organized way is known as DBMS (i.e. Database Management System). Business organizations have been using these database systems for years.

At first, these systems were extremely simple. With the modern technology, however, database management systems have evolved. Even the most basic ones have powerful features you can take advantage of. The DBMSs youll see today can store large amounts of data and access the internet.

The new breed of data management is often implemented using an RDBMS (i.e. Relational Database Management System). This is derived from the classic DBMS. Relational database systems often have Web and server/client technologies. That means they can help businesses in managing various types of information and staying competitive in todays market.

This book will teach you how to use SQL and relational databases. By reading this book, youll learn how to manage large amounts of data using SQL.

What Is SQL?

SQL stands for Structured Query Language. This is the basic language used to interact with databases. The original version was created by IBM during the 70s. During 1979, right after IBM released the prototype, Relational Software Inc. published the first SQL tool in the world. They called this product ORACLE. This product became so successful the entire company is now called Oracle Corporation. Today, ORACLE is one of the leaders in database technologies.

You can pronounce SQL in two ways:

1. Read the letters one by one, as in S-Q-L

2. Read the letters as Sequel

Modern users prefer the second way of pronouncing the name. Basically, you will use SQL to tell a database about your needs and wants. This process is similar to ordering food in a restaurant: you can utilize SQL to get the information you need.

Databases

Simply put, databases are groups of information. Some people consider databases as organized mechanisms that can store information, through which users can access data efficiently and effectively.

You are actually using databases without knowing it. A phonbook is considered as a database it contains information about peoples names, phone numbers, and physical addresses. The information is presented in alphabetical order, which allows you to find certain pieces of data easily.

Here is an image of a simple database:

Relational Databases An Introduction

This is a database segregated into tables or logical units. These tables are interconnected inside the database. Relational databases allow you to break data into smaller units. Thus, you can easily maintain your database and optimize it based on the needs of your organization. Heres a visual representation of a relational database:

Client/Server Technology An Introduction

Previously, mainframe computers dominated the computer industry. Mainframe computers are machines that possess large, robust systems capable of storing and processing information. People interacted with mainframe computers using dumb terminals (i.e. terminals not capable of thinking on their own). To perform their functions, dumb terminals relied on the computers storage, memory, and processor. This setup worked excellently. Actually, some companies are still using them in their business operations. However, a better solution was developed: the client/server technology.

In client/server systems, the main computer (i.e. the server) can be accessed using a network usually a WAN (wide area network) or a LAN (local area network). Users typically access the server using desktop computers or other servers, rather than dumb terminals. Every computer, referred to as a client, has access to the system, enabling interaction between the server and the client/s.

The major difference between mainframe and client/server environments is that with the latter, the users computer can think on its own and run its own applications. Because of these features, client/server environments are preferred by modern businesses and non-profit organizations.

Heres a visual representation of a client/server setup: