The Web Server Environment - Database Processing: Fundamentals, Design, and Implementation - page 500

Figure 11-54
Continued
(b) Graphical representation of the Phonetype Global Element
(c) Graphical representation of the XML Schema
In Figure 11-54(a), for example, the Address group is defined as the global element
AddressType, and the Phone group is defined as the global element PhoneType. According to
the XML Schema standard, these are global elements because they reside at the top level of the
schema.
If you examine Figure 11-54(a) further, you will see that both Customer and Salesperson
within Customer use the AddressType and PhoneType global definitions. They are refer-
enced by the notations type = "AddressType" and type = "PhoneType." By using these global
definitions, if either PhoneType or AddressType is changed, the definition of Customer and
Salesperson will inherit the change.
One other change in this figure is that the cardinality of the Phone group of Salesperson
has been set to 1..3. This notation means that at least one Phone group is required and as many
as three are allowed. As you learned in Chapter 5, representing such multivalued attributes in