Chapter 2 Building an XML model

KeyRef general properties

The General page of a keyRef property sheet displays the following properties:

Property

Description

Name

Name of the keyRef constraint. It must be a no-colon-name

 

(See Glossary)

Code

Code of the keyRef constraint. It must be a no-colon-name

Comment

Descriptive label of the keyRef constraint

Stereotype

Sub-classification used to extend the semantics of an object

 

without changing its structure. It can be predefined or user-

 

defined

ID

ID of the keyRef constraint. Its value must be of type ID and

 

unique within the model containing the keyRef constraint

Reference

Name of a key or a unique constraint defined in the current

 

model (or another model with a specified namespace). The

 

Reference value must be a qualified name (See Glossary)

Selector (XPath)

An XML Path Language expression that selects a set of

 

elements across which the values specified in the Fields page

 

must be unique. There must be one and only one selector

 

 

For more information on Selector or XPath, see section Defining an identity constraint selector.

KeyRef fields properties

The Fields page of a keyRef property sheet displays a list of XPath expressions.

If there is more than one field (or XPath expression), the combination of fields must be unique.

For information on XPath expressions, see section Defining an identity constraint selector.

Creating an identity constraint

You create an identity constraint from an element property sheet.

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Sybase XML manual Creating an identity constraint, KeyRef general properties, KeyRef fields properties