Home > Articles

This chapter is from the book

This chapter is from the book

A Sample Database

This section describes the sample database that we'll use throughout the rest of this book. It provides a source of examples for you to try as you learn to put MySQL to work. We'll draw examples primarily from two of the situations described earlier:

  • The organizational secretary scenario. We need something more definite than "an organization," so I'll make one up with these characteristics: It's composed of people drawn together through a common affinity for United States history (called, for lack of a better name, the U.S. Historical League). The members maintain their affiliation by renewing their membership periodically on a dues-paying basis. Dues go toward the expenses incurred by the League, such as publication of a newsletter, "Chronicles of U.S. Past." The League also operates a small Web site, but it hasn't been developed very much. Thus far, the site has been limited to basic information, such as what the League is about, who the officers are, and how people can join.

  • The grade-keeping scenario. You are a teacher who administers quizzes and tests during the grading period, records scores, and assigns grades. Afterward, you determine final grades, which you turn in to the school office along with an attendance summary.

Now let's examine these situations more closely in terms of two requirements:

  • You must decide what you want to get out of the database—that is, what goals you want to accomplish.

  • You must figure out what you're going to put into the database—that is, what data you will keep track of.

Perhaps it seems backward to think about what comes out of the database before considering what goes in. After all, you must enter your data before you can retrieve it. But the way you use a database is driven by your goals, and those are more closely associated with what you want to get from your database than with what you put into it. Presumably you're not going to waste time and effort putting information into a database unless you plan to use it for something later.

The U.S. Historical League

The situation for this scenario is that you as League secretary maintain the membership list using a word processing document. That works reasonably well for generating a printed directory but limits what else you can do with the information. You have the following objectives in mind:

  • You want to produce output from the directory in different formats, using information appropriate to the application. One goal is to generate the printed directory each year—a requirement the League has had in the past that you plan to continue to carry out. You can think of other uses for the information in the directory, too—for example, to provide the current member list for the printed program that's handed out to attendees of the League's annual banquet. These applications involve different sets of information. The printed directory uses the entire contents of each member's entry. For the banquet program, you need to pull out only member names (something that hasn't been easy using a word processor).

  • You want to search the directory for members whose entries satisfy various criteria. For example, you want to know which members need to renew their memberships soon. Another application that involves searching arises from the list of keywords you maintain for each member. These keywords describe areas of U.S. history in which each member is particularly interested (for example, the Civil War, the Depression, civil rights, or the life of Thomas Jefferson). Members sometimes ask you for a list of other members with interests similar to their own, and you'd like to be able to satisfy these requests.

  • You want to put the directory online at the League's Web site. This would benefit both the members and yourself. If you can convert the directory to Web pages by some reasonably automated process, an online version of the directory could be kept up to date in a more timely fashion than the printed version. And if the online directory can be made searchable, members could look for information easily themselves. For example, a member who wants to know which other members are interested in the Civil War could find that out without waiting for you to perform the search, and you wouldn't need to find the time to do it yourself.

I'm well aware that databases are not the most exciting things in the world, so I'm not about to make any wild claims that using one stimulates creative thinking. Nevertheless, when you stop thinking of information as something you must wrestle with (as you do when using your word processing document) and begin thinking of it as something you can manipulate relatively easily (as you hope to do with MySQL), it has a certain liberating effect on your ability to come up with new ways to use or present that information:

  • If the information in the database can be moved to the Web site in the form of an online directory, you might also be able to make information flow the other way. Suppose that members could edit their own entries online to provide updates for the database. Then you wouldn't have to do all the editing yourself, and it would make the information in the directory more accurate.

  • If you store email addresses in the database, you could use them to send email to members that haven't updated their entries in a while. The messages could show members the current contents of their entry, ask them to review it, and indicate how to make any needed modifications using the facilities provided on the Web site.

  • A database might help make the Web site more useful in ways not even related to the membership list. The League publishes a newsletter, "Chronicles of U.S. Past," that has a children's section containing a history-based quiz in each issue. Some of the recent issues have focused on biographical facts about U.S. presidents. The Web site could have a children's section, too, where the quizzes are put online. Perhaps this section could even be made interactive, by putting the information from which quizzes are drawn in the database and having the Web server query the database for questions to present to visitors.

Well! At this point the number of uses for the database that you're coming up with make you realize you might be getting a little carried away. After pausing to come back down to earth, you start asking some practical questions:

  • Isn't this a little ambitious? Won't it be a lot of work to set this up?

  • Anything's easier when you're just thinking about it and not doing it, of course, and I won't pretend that all of this will be trivial to implement. Nevertheless, by the end of this book you'll have done everything we've just outlined. Just keep one thing in mind: It's not necessary to do everything all at once. We'll break the job into pieces and tackle it a piece at a time.

  • Can MySQL be used to accomplish all these goals?

  • No, it can't, at least not by itself. For example, MySQL has no direct Web-programming facilities. But even though MySQL alone cannot do everything we've discussed, you can combine MySQL with other tools that work with it to complement and extend its capabilities.

    We'll use the Perl scripting language and the DBI (database interface) Perl module to write scripts that access MySQL databases. Perl has excellent text-processing capabilities, which allow for manipulation of query results in a highly flexible manner to produce output in a variety of formats. For example, we can use Perl to generate the directory in Rich Text Format (RTF), which can be read by all kinds of word processors, and in HTML format for Web browsers.

    We'll also use PHP, another scripting language. PHP is particularly adapted to writing Web applications, and it interfaces easily with databases. This allows you to initiate MySQL queries from Web pages and to generate new pages that include the results of database queries. PHP works well with Apache (the most popular Web server in the world), making it easy to do things such as presenting a search form and displaying the results of the search.

    MySQL integrates well with these tools and gives you the flexibility to choose how to combine them to achieve the ends you have in mind. You're not locked into some all-in-one suite's components that have highly touted "integration" capabilities but that actually work well only with each other.

  • And, finally, the big question: How much will all this cost? The League has a limited budget, after all.

  • This might surprise you, but it probably won't cost anything. If you're familiar with the usual ken of database systems, you know that they're generally pretty pricey. By contrast, MySQL is usually free. (See the MySQL AB Web site for specific details.) The other tools we'll use (Perl, DBI, PHP, Apache) are free, so, all things considered, you can put together a useful system quite inexpensively.

The choice of operating system for developing the database is up to you. Virtually all the software we'll discuss runs under both Unix (which I use as an umbrella term that includes BSD Unix, Linux, Mac OS X, and so forth) and Windows. The few exceptions tend to be shell or batch scripts that are specific to either Unix or Windows.

The Grade-Keeping Project

Now let's consider the other situation for which we'll be using the sample database.

The scenario here is that as a teacher, you have grade-keeping responsibilities. You want to convert the grading process from a manual operation using a gradebook to an electronic representation using MySQL. In this case, the information you want to get from a database is implicit in the way you use your gradebook now:

  • For each quiz or test, you record the scores. For tests, you put the scores in order so that you can look at them and determine the cutoffs for each letter grade (A, B, C, D, and F).

  • At the end of the grading period, you calculate each student's total score, and then sort the totals and determine grades based on them. The totals might involve weighted calculations because you probably want to count tests more heavily than quizzes.

  • You provide attendance information to the school office at the end of the grading period.

The objectives are to avoid manually sorting and summarizing scores and attendance records. In other words, you want MySQL to sort the scores and perform the calculations necessary to compute each student's total score and number of absences when the grading period ends. To accomplish these goals, you'll need the list of students in the class, the scores for each quiz and test, and the dates on which students are absent.

How the Sample Database Applies to You

If you're not particularly interested in the Historical League or in grade-keeping, you might be wondering what either of these scenarios have to do with you. The answer is that they aren't an end in themselves. They simply provide a vehicle by which to illustrate what you can do with MySQL and tools that are related to it.

With a little imagination, you'll see how example database queries apply to the particular problems you want to solve. Suppose that you're working in that dentist's office I mentioned earlier. You won't see many dentistry-related queries in this book, but you will see that many of the queries you find here apply to patient record maintenance, office bookkeeping, and so forth. For example, determining which Historical League members need to renew their memberships soon is similar to determining which patients haven't visited the dentist for a while. Both are date-based queries, so once you learn to write the membership-renewal query, you can apply that skill to writing the delinquent-patient query in which you have a more immediate interest.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020