Unit 1 Getting Started

AOIT Database Design Lesson 2 Database Basics

Student Resources

Resource Description

Student Resource 2.1 Worksheet: Star Wars and the Holocron Database

Student Resource 2.2 Worksheet: Database Scavenger Hunt

Student Resource 2.3 Worksheet: Learning About Non-Web Databases

Student Resource 2.4 Worksheet: How Data Affects People

Student Resource 2.5 Reading: What Is a Database?

Student Resource 2.6 Worksheet: Diagramming Simple Data Flow

Student Resource 2.7 Worksheet: Comparing Databases

Student Resource 2.8 Reading: The Evolution of Databases

Student Resource 2.9 Worksheet: The Evolution of Databases

Student Resource 2.1 Worksheet: Star Wars and the Holocron Database

Student Name:______Date:______

Directions: Complete the following questions as you watch the video Star Wars: The Holocron (found at http://www.youtube.com/watch?v=wuqSdtWADAc or http://www.wired.com/entertainment/hollywood/magazine/16-09/ff_starwarscanon?currentPage=all).

1. What is stored in the Holocron database?

2. What does a database administrator do?

3. Which employees at Lucasfilms might have job duties that require access to the Holocron?

4. What serious problems could Lucasfilm encounter without this database?

5. What are some other ways Lucasfilm could have tried to manage all of this character information? In your opinion, which way is best, and why?

Student Resource 2.2 Worksheet: Database Scavenger Hunt

Student Names:______Date:______

Directions: Work with your partner to find the following information using Internet-based databases.

What is the call number for the book Brave New World by Aldous Huxley?

Name of website

Website URL

Our answer

How much would one economy class round-trip ticket leaving two months from today from your nearest airport to London, England, cost?

Name of website

Website URL

Our answer

Visit eBay, and locate one item you would like to bid on.

Name of auction

Auction URL

Search terms you used to find this

If your school has automated online grade reporting, look up your grade in this class. (To protect your privacy, you don’t have to list your actual grades, but you do need to tell how many points are currently possible in order to show you have retrieved the information.)

Website URL

Search terms you entered

Points possible

Student Resource 2.3 Worksheet: Learning About Non-Web Databases

Student Name:______Date:______

Directions: Interview an adult you know (a parent, relative, neighbor, local businessperson, or teacher, for example) about databases he or she uses on a regular basis. Ask your interview subject to think about non-Web-based databases and to describe them for you. If your interview subject cannot think of a database he or she uses regularly, give them some examples, such as retail databases, record indexes, or inventory lists. You may ask any questions you choose but must include the following information:

Name of your interview subject:

Name of the database with which he or she works:

Purpose of this database:

When or why does your subject use this database?

How often is the database used?

What types of information are stored in the database?

How is this information used?

Be sure to record your findings carefully on this worksheet, and be prepared to share what you have learned with the class during an upcoming class discussion.

Student Resource 2.4 Worksheet: How Data Affects People

Student Names:______Date:______

Directions: Working with your partner, answer the following questions for two websites you worked with during the scavenger hunt. Use the example provided as a guide for your work.

Website How does this database help What are some of the problems people? unreliable data could cause people who use this database?

Library of Congress All books published in the United An incorrect call number could (http://catalog.loc.gov/) States are catalogued here. cause a checked-in book to Anyone can access this become lost; an incorrect author database to learn information name (or incorrect spelling of the about any title, such as the name) could separate one book author, year of publication, call by an author from the rest of his number, publisher name, how or her works. many pages it has, and so on.

Student Resource 2.5 Reading: What Is a Database?

This presentation explains how data gets stored in a database and how things work when users retrieve data from a database. In addition, the presentation talks about the different kinds of databases that are in use today, ranging from databases that serve several thousands of users at once to databases that are used only by one person.

A database is like a large computerized filing cabinet. Users ask questions (called queries) and retrieve files (called records) from the “cabinet.” Data in the database is not organized in a way that is typically “user friendly,” so users (people like you) use tools called database applications to help them retrieve and make sense of the data.

A database application oversees the user interface (UI), or user’s experience, when he or she is working with a database. It creates the screens we see, creates the forms we fill out, manages how reports are generated (and what reports we can create), and controls the order in which users ask for and receive data. Anything you see on the screen when working with a database is there because of the database application.

When you tell the database application what you want, it sends your request to the DBMS. The DMBS then translates your question into a search of the database. In reality, you are unlikely ever to notice the difference between the database application and the DBMS. In many applications, the two are integrated. This is the case for Microsoft Access, the program with which you’ll be dealing the most in this class.

The DBMS bridges the gap between what a user has asked for and where the information is stored. It is the DBMS’s job to go into the database, locate the requested information, and return it to the user via the application program. A DBMS does the hard work of locating records users require in only a fraction of a second. If people had to search by hand, the process could take days or even weeks!

Nearly everyone uses databases, whether they realize it or not. These are just a few of the uses for databases. What others can you think of?

Enterprise-level databases are the largest of all database systems. These are the databases that power large firms, like those in the travel and financial industries and government data warehouses. Enterprise- level databases can give thousands of users access to records all at the same time. One of the leading firms providing services to enterprise-level clients is Oracle. It has, almost single- handedly, transformed the way enterprise clients store and manage their data. You may have heard of the language Oracle uses to power its products, called SQL (pronounced ”sequel”). Learning SQL is a valuable career skill; in fact, some people spend their entire day, every day, working with SQL to manage and improve the enterprise database users’ experience.

Groups also use databases. Small teams in offices or labs can pool resources and information with databases. Imagine scientists working on a project together. Because of databases’ ability to pool large amounts of information and to make it available to people around the globe, colleagues don’t have to be in the same lab to be working to solve the same problems, share research findings, or analyze data.

Individuals can also benefit from databases, though households use “lower-tech” databases than the powerful enterprise- and workgroup-level databases that businesses and government bodies rely on. Many homes have several flat-file or hierarchical databases in operation or even run Microsoft Access to maintain a simple hierarchical database. Do you have a file on your computer with recipes, address books, or perhaps a list of all the DVD or video games you own? What about a computer file or scrapbook with a family tree? If so, you have a database. When thinking about individual databases, keep in mined the word individual. Databases at this level are very personal; they handle hundred, not millions of records, and are typically used by just a handful of people. These databases add productivity to our home systems, collections, and other data, but they do not offer the depth available to enterprise and workgroup-level users.

Databases power our library systems, ticket sales systems, bank records, retail cash registers, and any number of information-rich websites. Perhaps more than any other type of software, databases have revolutionized the way we work, play, and learn.

Usually, four elements work together to make a database work. This is true for giant Oracle databases that banks use and also for the databases you will be creating in this class using Microsoft Access. 1. The user enters data into a user interface that is usually a form for entering data into a database. 2. The database has an application program that takes the data entered into the form and communicates the information to the DBMS. 3. The DBMS stores the information in the database and remembers the location where it is stored. When a user asks to retrieve data, the process is like this: 1. The user inputs information about the data he or she wants using a user interface. 2. The application program takes the information from the user interface and communicates it to the DBMS. 3. The DBMS finds the requested information in the database and sends it back to the application program. 4. The application program uses the user interface to communicated the requested information to the user.

Student Resource 2.6 Worksheet: Diagramming Simple Data Flow

Student Name:______Date:______

Directions: Think about what you have learned in this lesson, and draw a picture or diagram in the space below showing how you would access a database to look up your grades. How do your grades get from the database to your computer screen?

Use the diagramming symbols used in Student Resource 2.5, Reading: What Is a Database?

Student Resource 2.7 Worksheet: Comparing and Contrasting Databases

Directions: The samples below show three different types of databases. Each was popular during a certain period in the history of databases. Before you begin the reading, note the obvious differences that you find between the different types of databases at the bottom of this page.

Flat-File Database Sue Daly 305 E 5 St Newton MA 02459 Angela Elrod 3332 Hazel Ave Tempe AZ 85281 Kim Graves 6605 Walker Ave Norman OK 73072 Tim Miller 5581 W 34 St San Jose CA 95113 Jeff Pugh 8531 S Louis Blvd St Cloud MN 56301 Marilyn Pugh 8531 S Louis Blvd St Cloud MN 56301

Hierarchical Database

Relational Database Person Table Address Table Person Address Person First_Name Last_Name Addre Street Address City _ID _ID _ID ss_ID 1 1 1 Sue Daly 1 305 E 5 St Newton 2 2 2 Angela Elrod 2 3332 Hazel Ave Tempe 3 3 3 Kim Graves 3 6605 Walker Ave Norman 4 4 4 Tim Miller 4 5581 W 34 St San 5 5 5 Jeff Pugh Jose 6 5 6 Marilyn Pugh 5 8531 S Louis St Cloud Blvd

Note some of the obvious differences between these databases:

Student Resource 2.8 Reading: The Evolution of Databases

As you may have guessed, the development of databases follows the general development of computer technology quite closely. Just as computers have become more complex, so have databases. People have always needed to organize data. Ancient cultures used papyrus and vellum scrolls. Early modern cultures kept records on tally sticks and in parchment scrolls. More modern peoples used tools like ledger books. These have all been good ways to keep track of information, but today’s businesses need truly powerful tools to help them organize and sort data and to generate reports about the information they have.

The Earliest Databases In 1945, before computers as we know them even existed, people were thinking and writing about ways to organize data. One man, Vannevar Bush, began working with the U.S. Census Bureau to organize data from the 1950 Census. They created a counting method that used a flat-file database design. The system helped the Census Bureau count and organize data more easily than ever before. Flat files store all information for a record on a single line. A record from a flat-file database might look like this: Sue Daly 305 E 5 St Newton MA 02459 Organizing data with computers, even in this basic way, was a giant leap forward for information management. However, the flat-file system was far from perfect. For instance, many departments could access a flat-file database, but if one group needed to make a change, the group had to let all the others know to update their copies of the record. Any time someone added new data, everyone had to add it, even if they didn’t need it. There was also a lot of repeated data in these files, especially as the systems became more complex. As you can imagine, this led to lots of internal errors, and the constant maintenance took up a lot of time. Another problem with the flat-file system was that it relied on the hardware running it. What if the machine with the database became obsolete or had to be replaced, and what if the new hardware was from a different company? The database could be lost unless someone converted it into a format that could be used by the new replacement machines. Computers then did not know how to read data that was not programmed for that one brand of machine. In time, people came to see that the information stored in databases needed to be independent of its hardware (just as Bush had known all along). By the early 1960s, more government agencies had noticed the flat-file databases. NASA was working on the Saturn V and Apollo missions and was very interested in using databases to help track parts and expenses for the projects. NASA’s interest led to the development of the first hierarchical database in 1964. If you have ever seen a drawing of a company’s organizational chart, you can imagine how a hierarchical database is designed. This model is based on the parent and child idea. Each record has a parent and/or child. This model allowed computers to access data more quickly than was possible with a flat-file system, but the design was also very rigid. It is nearly impossible to make changes to a hierarchical database once it is in use. The hierarchical model looks like this:

In 1966, the first database was offered for sale to businesses. Large companies, such as airlines, began buying these hierarchical systems to help them organize tickets and schedules and to streamline their internal functions. The modern, information-driven office was born.

Databases in Transition After years of working with hierarchical databases, developers began to look for other ways to store and manage large sets of data. The next design to emerge (around 1969) was the network database model. It is a lot like the hierarchical one. It also has parent and child relationships, and records are connected to each other with special physical pointers. Unlike the hierarchical model, network databases let records have many parents and children. This is called a many-to-many approach. People use network databases to keep track of information such as the many roles one person plays in an organization, all of the people assigned to work on a certain project, and so on. Because more than one record can be the parent for each entry (and because each entry may have several “children”), a network database can be more complex than a hierarchical one. The network model looks like this:

Relational Databases Though popular, network databases never really dominated the market. Once people saw how well the one-to-many style worked, they wanted even more flexible ways to organize data. One IBM engineer, E. F. “Ted” Codd, was very interested in this idea. In June 1970, he wrote an article outlining the basic idea for the relational model. In it, he explained a simple but very flexible file structure made up of several tables. Each table has a purpose and can be related to other tables with keys. For example, an address database might have one table for people’s names, another for their street address, another for their city, and so on. The item in a table that tells its main purpose is called the primary key. A foreign key, usually an ID number, can be added to any table to show how it links (or relates) to any another table. Foreign keys replaced the physical pointers used in the hierarchical and network models. With the new relational model, database designers could show the many ways data relates to other data and could sort it easily to generate highly specialized reports to show the links present among many pieces of data.

As relational databases were catching on, a new company, Oracle, was founded. It now leads the database field. One of the key reasons for Oracle’s success has been its development and use of the computer language SQL (pronounced “sequel”). SQL allows programmers to write code that will work with applications made by any number of companies. In short, SQL offers a standard way to write computer code to query databases.

Databases and the Masses The relational model is still the most popular database style. However, a newer design has emerged in the past 20 years, the object-oriented model. It works well with applications programmed using object- oriented languages such as Java, C++, and Objective C. These databases are very fast and can handle lots of data easily. This model is a hybrid. It pairs the relational model with the benefits of object-oriented programming capabilities. Relational databases are found in nearly every business you can think of. Databases run our libraries, school systems, and ticket sales systems. Bank records, cash registers, and information-rich websites also use databases. Perhaps more than any other type of software, databases have revolutionized the way we work, play, and learn.

Student Resource 2.9 Timeline: The Evolution of Databases

Directions: On a piece of chart paper, draw a timeline, and place the key events in the evolution of databases.

Before you begin, read through this worksheet to make sure you understand the assignment and the assessment criteria. To get an idea of how you might organize your timeline and include analysis and pictures, study the exemplar on the following page that shows a timeline about the history of computer programming. Use the timeline that is started for you below to create a rough draft of the events you want to include on your timeline.

Requirements  Include at least six major events and at least four of the database models. Your timeline should be a graphic representation that tells the story of how databases have evolved.  To add to the story line, include at least three boxes that give some sort of analysis of the information. The analysis could be a cause and effect, the implications of a certain event, or a prediction about where databases will go in the future, based on how they have evolved in the past.  To enhance the story that your timeline tells, include at least two illustrations of events on the timeline.

1950 - US Census uses flat file databases

Check to make sure your assignment meets or exceeds the following assessment criteria:

1. The timeline’s events tell the story of how database technology has evolved over time.

2. The dates and events listed in the timeline are correct.

3. The timeline includes some analysis of the events, such as cause-and-effect relationships, implications, and/or predictions.

4. The illustrations provide a visual image of some aspects or events in the evolution of databases.

5. The timeline is neat, legible, and presentable.

The personal computer made programming accessible to a much larger segment of the population.

As the Internet thrives, there will continue to be an increasing demand for programmers who know web-scripting languages.

Object-oriented programming makes it easier for programming groups to work on different parts of the same product simultaneously. This makes product development cycles shorter.