XML Schema selector element
Definition and usage
The selector element specifies the XML path language (XPath) expression, which is an expression that identifies constraints to select a set of elements (unique, key, and keyref elements).
element information
| appearance times | once |
| parent element | key、keyref、unique |
| content | annotation |
grammar
<selector id=ID xpath=subset of XPath expression any attributes > (annotation?) </selector>
| 屬性 | 描述 |
|---|---|
| id | 可選。規定該元素的唯一的 ID。 |
| xpath | 必需。規定相對於所聲明的元素的 XPath 表達式。該表達式識別應用識別約束（所聲明的元素）的子元素。 |
| any attributes | 可選。規定帶有 non-schema 命名空间的任何其他屬性。 |
