Database Reference
In-Depth Information
you can then apply it to any other database you're designing. Your focus, then, should al-
ways be on the concept or technique being presented, not on the example itself.
Nevertheless,Iuseasingledatabaseexampleasacasestudytoillustratethestepsinvolved
in the design process. This enables me to present the process with some degree of continu-
ity. As the database design process unfolds, I apply each technique to designing the data-
base for the fictitious company in the case study. I provide only a few details about the
company in this chapter, but I'll supply more as I present each new concept or technique.
Mike's Bikes, our case-study business, is a new bike shop located in a small suburb called
Greenlake,notfarfromdowntownSeattle.Ithasbeenopenforonlytwomonths,andbusi-
nessisgrowingsteadily.Mike,theshop'sowner,hasbeenconductinghisdailybusinesson
paper. He records sales on preprinted forms, maintains employee and vendor information
on sheets of paper (storing them in folders), and writes information about his regular cus-
tomersonindexcards.Asaresult,Mikespendsalotoftimemaintainingallofthisdata.He
owns a computer but uses it mainly to play games, watch videos on YouTube, write email,
keep in touch with friends on Facebook, and visit various golf sites. The only business-re-
lated task he performs on the computer is keeping track of the bike shop's inventory using
a spreadsheet program.
Recently, Mike learned that using a database would be a good way to store and work with
data related to his business. Using a database would greatly diminish the amount of time
he currently spends maintaining his data, and he could always ensure that the data is up-
to-date and that the information is accurate. Although he thinks a database is a good idea,
he's aware of the fact that he doesn't know the first thing about properly designing one.
Undaunted, Mike has decided to hire a database consultant to design the database for him.
You are, in this fable, the consultant he has hired for the project. As the database design
processunfoldsthroughoutthenextseveralchapters,you'llapplyeachtechniquetodesign
the database for Mike's Bikes. As you learn new concepts or techniques, Mike will supply
you with the information you need to complete the design of his database.
Defining the Mission Statement
Inthepreviouschapter,youlearnedthatthe
mission statement
declaresthespecificpurpose
of the database in general terms and that you define it at the beginning of the database
designprocess.Furthermore,itprovidesyouwithafocusforyourdesigneffortsandkeeps
you from getting diverted and making the database structure unnecessarily large or com-
plex.
