Database Development For Dummies

Allen G. Taylor

• Publisher: For Dummies
• Year: 2011
• Print ISBN: 9780764507526
• eBook ISBN: 9781118085257
• Edition: 1
• Topic: Computer Science
• Subtopic: Software Development
• Index: Computer Science

Powerful, low-cost database development tools make it possible for virtually anybody to create their own database—and this hands-on guide makes it fun and easy

Databases permeate every nook and cranny of our highly connected, information-intensive world, from ATMs to personal finance, online shopping, and networked information management. Databases have become so integral to the business environment that, nowadays, it's next to impossible to stay competitive without the assistance of some sort of database technology—no matter what type or size of business you run. But developing your own database can be tricky. Whether you want to keep records for a small business or run a large e-commerce website, developing the right database system can be a major challenge. Which is where Database Development For Dummies ?comes in.

From data modeling methods and development tools to Internet accessibility and security, ?this comprehensive guide shows you, step-by-step and with illustrations, everything you need to know about building a custom system from the ground up. You'll learn to:

• Model data accurately
• Design a reliable functional database
• Deliver robust relational databases on time and on budget
• Build a user-friendly database application
• Put your database on the Web

The book acquaints you with the most popular data modeling methods and shows you how to systematically design and develop a system incorporating a database and one or more applications that operate on it. Here's more of what you'll discover in the book:

• Database architecture and how it has evolved
• How database technology affects everyday life
• A structured approach to database development
• How to create an appropriate data model
• How to develop a reliable relational design
• The complexities that you're likely to encounter in designing a database and how to simplify them
• Implementing your design using Microsoft Access 2000, SQL Server, and other powerful database development tools
• Database security
• Ten rules to know when creating a database
• Another ten rules to know when creating a database application

If you need a database tailored to you and your company's current and future data storage and management needs, this is the book for you. Get? Database Development For Dummies ?and discover what it takes to design, develop, and implement a sophisticated database system.

Part I

Basic Concepts

In this part . . .

**IN a DROPCAP**

In Part I, I give you the background information you need in order to build high-quality databases and database applications. I describe the different classes of databases and what makes them different. I also describe the critical role that databases play in our data-saturated world, including the so-called “new economy.” I offer a brief history of data processing and the advent of database systems, leading up to coverage of what databases and database applications are, followed by a structured approach to building them. I also describe some of the major pitfalls of database development, and explain how to avoid them.

Chapter 1

Database Processing

In This Chapter

Sorting out the different classes of databases

Discovering what databases can do for you

Understanding database processing

Database processing is one of the more common operations performed on computers today. In fact, only word-processing and spreadsheet packages outrank database management systems among the most popular business tools. Everyone, from the largest corporate entities to private individuals, wants to keep track of something. Applications such as order entry, accounts receivable, accounts payable, and general ledger all incorporate databases. Companies keep track of their customers, product inventories, employees, and capital assets in databases. Businesses, governments, and organizations around the world would grind to a halt without databases.

The Different Classes of Databases

Large international corporations and national governments have substantially different data management needs from those of a private individual or even a small to medium-sized company. Large database users have demanding capacity and performance requirements and are willing to pay what it takes to meet those requirements. That kind of power would be serious overkill for an individual, local non-profit organization, or small business, and would be too expensive anyway. As a result, different database development tools are available for addressing different market segments. Some of these tools, called database management systems (DBMSs), are capable of supporting huge, high-performance databases, but require very powerful (and expensive) mainframe computers to do the job. Other tools run on personal computers, and are limited in the size and performance of databases they are able to support.

Enterprise databases

The first databases, back in the 1960s, although primitive by today’s standards, were applied to large, enterprisewide problems, such as airline reservation systems, and maintaining bills of materials for NASA spacecraft. In those days, computers were big, expensive to buy, and expensive to run. Only large corporations or government agencies could afford to own the computers that could support a database. As a result, the first databases were enterprise class databases. The database management systems that were used to create databases were powerful, robust, and resource-hungry.

As computer power has steadily increased and become less expensive, enterprise class databases have become even more powerful and are capable of supporting much larger collections of data. The data on such systems is also accessible to thousands of simultaneous users. Today, large organizations get orders of magnitude larger and faster databases for much lower cost than was true in the early days of database, but costs of such systems are still out of reach for individual users. This is not a big problem, because few individuals need a database system that supports thousands of simultaneous users.

Personal databases

In 1975, the first, primitive personal computer kits arrived on the scene, and in 1976 you could buy one already assembled. (Pretty slick, eh?) These machines were not powerful enough to support even a very cut-down database management system, but performance improved steadily. With the advent of the IBM PC coupled with hard disk storage, database technology started to proliferate on personal computers in 1981.

Personal database products are much simpler than their enterprise class ancestors. For one thing, they have to support only one simultaneous user, rather than thousands. For another, typical single-user applications use much smaller databases than those needed to run an airline reservation system or something similarly huge. Furthermore, because there were soon millions of personal computers compared to a much smaller installed base of mainframe computers, the economies of scale kick in and it is possible to sell personal databases at a much lower price than mainframe databases and still make a profit. Development costs are spread over many more units.

Today, personal computers have become so powerful that the DBMS products available on them have much more capacity and much better performance than did the mainframe DBMS products of yesteryear.

The Y2K catastrophe

Remember the big Y2K scare? People were seriously concerned that on the stroke of midnight on December 31, 1999, the world as we knew it would come to an end. Well, maybe not come to an end, but terrible things would surely happen. Airliners would fall out of the sky. Elevators would drop down their shafts and crash into the building basement floor. Car engines would turn off while you were cruising at 60 mph on the freeway. Libraries would send fine money to patrons with overdue books, because the books were returned a hundred years before they were taken out. Who knows? Maybe even Pez® dispensers would cease functioning.

Billions of dollars were spent worldwide to exorcise the Y2K demon. Where did all that money go? Most of it went to modifying database files and the applications that accessed them. Some was spent on new equipment, because the threat of Y2K disaster made it easier for workers to convince management that, to be safe, they needed new Y2K-compliant computers or Pez dispensers.

Workgroup databases

After millions of personal computers had been sold and installed in companies large and small, people came to a fundamental realization. Millions of people, each with their own personal computer, now had far greater ability to do their work faster and with less effort than had been the case before. Productivity had taken a quantum leap forward. However, each one of those personal computers was an isolated island of compute power and data storage. Productivity would be boosted even more if somehow the data and compute power residing on those personal computers could be shared.

Networking connected the personal computers together, and a new class of database — the workgroup database — was invented to take advantage of the new connectivity. Workgroup databases, accessed by perhaps up to 50 or 100 simultaneous users, filled the gap between the enterprise database and the personal database. Today, in small to medium-sized organizations, workgroup databases are the most common of the three database classes.

So Much Data, So Little Time

Ever since electronic computers first came into use in the late 1940s, they have generated data of all types much faster that had ever been possible using adding machines along with paper and pencil. Since then, the power of computers has been increasing at an exponential rate. Moore’s Law, named after Intel co-founder Gordon Moore, has held true for decades, stating that the power of computers doubles about every 18 months, as shown in Figure 1-1.

Figure 1-1: Growth of computer power as a function of time.

The amount of data that computers are able to process doubles at a comparable rate. As a result, we are being drowned in a veritable sea of data. Much of it is potentially valuable, but the situation has reached the point where data is being gathered so fast that much of it may never be put to use. Raw data has very little value. It gains value when it is organized in such a way that it conveys meaningful information to people who can use that information. Databases are our most powerful tool for organizing data into potentially valuable information.

Databases and privacy: We know who you are, and we know where you live

One of the unanticipated consequences of the tremendous growth in the amount of data that is generated every day is the erosion of personal privacy. A generation ago, as long as you were not a famous or notorious person, nobody knew much of anything about you. Your private life was just that, private. If you wanted to drop out of sight, move somewhere else and start a new life, it was not very difficult to do. Aside from a small number of people in your local community who had lived and worked with you, you were a complete unknown to the world at large. Those days are gone and will never return.

Now it is practically impossible to buy anything, sell anything, or travel anywhere by air, rail, or sea, without the fact being recorded in a database somewhere. Ever since the days of J. Edgar Hoover, the FBI has prided itself in its ability to know the whereabouts of and important facts about individuals it considers important. Nowadays, you don’t have to be the FBI or the CIA to have that kind of knowledge about anyone you care to know about. Mer-chants, airlines, and travel agents have data on your living and buying habits. With the recent rash of mergers of all kinds of organizations into larger entities, this data is becoming centralized. Residing in databases that can be “mined” for useful information, companies can find out not only who you are and where you live, but also what you like to eat, what you like to read, who your favorite musicians and entertainers are. They know what your favorite sports teams are, and what sports you like to participate in yourself. They know where you shop and how often. They know when you are about to run out of something you buy regularly. They know when your kids are born, when they are about to enter kindergarten, when they will graduate from high school, and when they ...

Table of contents

• Title
• Contents
• Introduction
• Part I : Basic Concepts
• Chapter 1: Database Processing
• Chapter 2: Database Development
• Part II : Data Modeling: What Should the Database Represent?
• Chapter 3: The Users’ Model
• Chapter 4: The Entity-Relationship Model
• Chapter 5: The Semantic Object Model
• Chapter 6: Determining What You Are Going to Do
• Part III : Database Design
• Chapter 7: The Relational Model
• Chapter 8: Using an Entity-Relationship Model to Design a Database
• Chapter 9: Using a Semantic Object Model to Design a Database
• Part IV : Implementing a Database
• Chapter 10: Using DBMS Tools to Implement a Database
• Chapter 11: Addressing Bigger Problems with SQL Server 2000
• Chapter 12: Using SQL to Implement a Database
• Part V : Implementing a Database Application
• Chapter 13: Using DBMS Tools to Implement a Database Application
• Chapter 14: SQL and Database Applications
• Part VI : Using Internet Technology with Database
• Chapter 15: Database on Networks
• Chapter 16: Database Security and Reliability
• Part VII : The Part of Tens
• Chapter 17: Ten Rules to Remember When Creating a Database
• Chapter 18: Ten Rules to Remember When Creating a Database Application
• Glossary