Complete XML Schema Reference
The selector element specifies an XPath expression that selects a set of elements for an identity constraint (unique, key, and keyref elements).
(The ? sign declares that the element can occur zero or one time inside the selector element)
| Attribute | Description |
|---|---|
| id | Optional. Specifies a unique ID for the element |
| xpath | Required. Specifies an XPath expression, relative to the element being declared, that identifies the child elements to which the identity constraint applies |
| any attributes | Optional. Specifies any other attributes with non-schema namespace |
Complete XML Schema Reference
The perfect solution for professionals who need to balance work, family, and career building.
More than 10 000 certificates already issued!
The HTML Certificate documents your knowledge of HTML.
The CSS Certificate documents your knowledge of advanced CSS.
The JavaScript Certificate documents your knowledge of JavaScript and HTML DOM.
The jQuery Certificate documents your knowledge of jQuery.
The XML Certificate documents your knowledge of XML, XML DOM and XSLT.
The ASP Certificate documents your knowledge of ASP, SQL, and ADO.
The PHP Certificate documents your knowledge of PHP and SQL (MySQL).
| WEB HOSTING |
|---|
| Best Web Hosting |
| PHP MySQL Hosting |
| Best Hosting Coupons |
| UK Reseller Hosting |
| Cloud Hosting |
| Top Web Hosting |
| $7.95/mo SEO Hosting |
| Premium Website Design |
| WEB BUILDING |
|---|
| Download XML Editor |
| FREE Website BUILDER |
| Free Website Templates Free CSS Templates |
| Make Your Own Website |
| W3SCHOOLS EXAMS |
|---|
|
Get Certified in: HTML, CSS, JavaScript, XML, PHP, and ASP |
| W3SCHOOLS BOOKS |
|---|
|
New Books: HTML, CSS JavaScript, and Ajax |
| STATISTICS |
|---|
|
Browser Statistics Browser OS Browser Display |
| SHARE THIS PAGE |
|---|