XML Schema selectorElement

XML Schema 参考手册Complete XML Schema Reference Manual

Definition and Usage

The selector element specifies an XML Path Language (XPath) expression that selects a set of elements for the identity constraints (unique, key, and keyref elements).

Element Information

  • Parent element: key, keyref, unique

Syntax

<selector
id=ID
xpath=a subset of XPath expression
any attributes
>

(annotation?)

</selector>

(The ? symbol declares that this element can occur zero or one time within the restriction element.)

Attributes Description
id Optional. Specifies a unique ID for this element.
xpath Required. Specifies an XPath expression relative to the declared element. This expression identifies the child elements to which the identity constraint (the declared element) applies.
any attributes Optional. Specifies any other attributes with a non-schema namespace.

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