B.4 Domain Data Types

arbitrary_id

An attribute whose value is unique for all instances of the class, but whose content is unimportant.

Count

A nonnegative number used to indicate a count of items, e.g., the number of items in an order.

Money

An amount of money. All bookstore orders are handled in U.S. Dollars.

Note: In a multicurrency system, this type would also identify the currency (U.S. Dollar, Euro, British Pound, etc.) and quite possibly conversion rate information.

date

A calendar date and time.

ElapsedTime

The time that elapses between two points in time, expressed in terms of days, hours, minutes, and seconds.

MonthYear

A date specified only to the precision of a month and year.

Year

A calendar year, used primarily for specifying copyright dates. Since the bookstore does not handle books copyrighted prior to the 20th century (copyrights, after all, ultimately expire within a century or so), this does not need to deal with dates prior to 1900.

ISBNBookNumber

The ISBN (International Standard Book Number) is a unique identification number for any book in publication.

The ISBN is defined in ISO Standard 2108. It consists of ten digits organized into four parts: group identifier, publisher identifier, title identifier, and check digit. Each part is separated by hyphens or spaces, e.g. "ISBN 0 571 08989 5" or "ISBN 90-70002-34-5."

The number of digits in the first three parts of the ISBN (group identifier, publisher prefix, title identifier) varies. The number of digits in the group number and in the publisher prefix is determined by the quantity of titles planned to be produced by the publisher or publisher group. Publishers or publisher groups with large title outputs are represented by fewer digits.

For more information on the ISBN, see www.isbn.org.

ISBNGroupIdentifier

A unique code that identifies a country, area, or language area participating in the ISBN system. Some members form language areas (e.g., German language group = group number 3) or regional units (e.g., South Pacific = group number 982).

Each agency is responsible for assigning codes to publishers who, in turn, complete the ISBN by assigning codes to the books they publish.

ISBNPublisherPrefix

A code that uniquely identifies a publisher and that becomes the publisher component of the book's ISBN (International Standard Book Number).

The U.S. ISBN Agency is responsible for the assignment of the ISBN Publisher Prefix to those publishers with a residence or office in the U.S. that are publishing their titles within the U.S. Similar agencies exist for other countries.

ISBNTitleCode

The part of the ISBN assigned by the publisher to identify the books published by that publisher. Contrast this with ISBNBookNumber and ISBNPublisherPrefix.

PersonalName

A name of a person, consisting of an optional title (Mr., Ms., Dr., etc.), a required first and last name, a suffix (Jr., Sr.), and an optional middle name or initial.

WebsiteURL

A Uniform Resource Locator (URL), commonly known as a "web address," used to identify a site on the World Wide Web.

InternetEmailAddress

An ordinary e-mail address, generally of the form user@domain. The bookstore performs no validation on the e-mail address other than to check that there is an @ somewhere in it (without an @, the address would be considered local to the bookstore's domain).

MailingAddress

An address sufficient for the delivery of mail or packages. This may be a street address or a post office box.

ShipmentTrackingNumber

A number assigned by a package delivery company (sometimes called an "airbill" or "waybill" number) to identify a shipment uniquely in the system.

TelephoneNumber

A telephone number, specified in a way that it can be dialed from the bookstore's offices in the United States. Numbers without country codes are assumed to be in the North American Numbering Plan (United States, Canada, and Caribbean); all other telephone numbers will include a country code.

BankCardAccountNumber

An account number for a standard credit or debit card (commonly known as a "bank card") that can be used for payment.

BankCardApprovalCode

One of several response codes that the credit card company can return to indicate whether a charge has been approved or declined and the reason for approving or declining the charge.

Enumeration:

approved

Charge is approved for the amount requested.

overLimit

The charge would put the credit card over its limit, or the credit card is already over its limit. This error may also be returned if a charge is declined because account is overdue.

noAccount

No account has been found with this account number. The account number may have been entered incorrectly.

connectionFailed

No decision could be made, as the connection to the credit card company failed. Retry the charge.

accountDataMismatch

The supporting data (name, address) provided with the charge do not match the account.

expired

The card is expired. This does not mean that the expiration date entered is incorrect (the expiration date input parameter is checked only against the bank's records), but rather that the account is expired regardless of the date entered on the charge request. This usually happens when a new card is mailed to the customer but the card has not yet been activated.

UniversalProductCode

A unique code assigned to all commercial products. This is the famous "bar code" found on everything from groceries to books, recordings, and software. UPC Codes are assigned by the Uniform Code Council (UCC: website http://www.uc-council.org/).

For a detailed explanation of UPC codes, see http://www.howstuffworks.com/upc.htm.

VersionString

A string used to identify the version of a software product. Every product seems to have its own scheme for version numbering, so we treat this as merely an arbitrary string.