Database and Expert System Technology - Information Systems Reengineering, Integration and Normalization - page 63

Patient Record

Patient

*

Recordfolder

*

*

Medical record Borrow

|

+

Outpatient
record

Loan_
History

AE record Ward record

Fig. 2.11 A data type definition graph for patient record

2.5.2 XML Schema Definition (XSD) and XSD Graph

XSD (Fong 2005 ) is in the logical level of the XML model and is used in most
Web applications. At present, there is no standard format for the conceptual level
of the XML model. Therefore, we introduce an XSD Graph as an XML conceptual
schema for representing and confirming the data semantics according to the user
requirements in a diagram. The XSD Graph consists of nodes representing all ele-
ments within the XSD, and can capture the data semantics of root element, weak
elements, participation, cardinality, aggregation, generalization, categorization, and
n-ary association. These data semantics can be implemented by the structural con-
straints of XSD such as key, keyref, minOccurs, maxOccurs, Choice, Sequence, and
extension. They can be shown as follows:

Element
Element are tags with texts between them

• Propernesting