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XML Schema field Element

Complete XML Schema Reference

Definition and Usage

The field element specifies an XPath expression that specifies the value used to define an identity constraint.

Element Information

Parent elements: key, keyref, unique

Syntax

<field
id=ID 
xpath=XPath expression
any attributes
>

(annotation?)

</field>

(The ? sign declares that the element can occur zero or one time inside the field element)

Attribute	Description
id	Optional. Specifies a unique ID for the element
xpath	Required. Identifies a single element or attribute whose content or value is used for the constraint
any attributes	Optional. Specifies any other attributes with non-schema namespace

Example 1

The following example shows a field element that specifies the "userID" attribute as the field to use for the identity constraint:

<xs:field xpath="@userID"/>

Complete XML Schema Reference

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