XPath實例

XPath實例
翻譯：Linyupark / 2006-03-24

Let's try to learn some basic XPath syntax by looking at some examples.
讓我們來嘗試通過觀察一些實例來學習基礎的XPath語法

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The XML Example Document

We will use the following XML document in the examples below.
我們將使用下面這個XML文檔來進行實例

"books.xml":

<?xml version="1.0" encoding="ISO-8859-1"?>

<bookstore>

<book category="COOKING">
  <title lang="en">Everyday Italian</title>
  <author>Giada De Laurentiis</author>
  <year>2005</year>
  <price>30.00</price>
</book>

<book category="CHILDREN">
  <title lang="en">Harry Potter</title>
  <author>J K. Rowling</author>
  <year>2005</year>
  <price>29.99</price>
</book>

<book category="WEB">
  <title lang="en">XQuery Kick Start</title>
  <author>James McGovern</author>
  <author>Per Bothner</author>
  <author>Kurt Cagle</author>
  <author>James Linn</author>
  <author>Vaidyanathan Nagarajan</author>
  <year>2003</year>
  <price>49.99</price>
</book>

<book category="WEB">
  <title lang="en">Learning XML</title>
  <author>Erik T. Ray</author>
  <year>2003</year>
  <price>39.95</price>
</book>

</bookstore>

View the "books.xml" file in your browser.

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Selecting Nodes
選擇節點

We will use the Microsoft XMLDOM object to load the XML document and the selectNodes() function to select nodes from the XML document:
我們使用了XMLDOM對象來加載XML文檔並用selectNode()函數來進行XML文檔上節點的選擇：

set xmlDoc=CreateObject("Microsoft.XMLDOM")
xmlDoc.async="false"
xmlDoc.load("books.xml")

xmlDoc.selectNodes(path expression)

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Select all book Nodes
選擇所有book節點

The following example selects all the book nodes under the bookstore element:
下面這個實例就會選擇所有bookstore元素以下的book節點：

xmlDoc.selectNodes("/bookstore/book")

如果你有IE5以上的版本你可以自己來做一下.

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Select the First book Node
選擇第一個book節點

The following example selects only the first book node under the bookstore element:

xmlDoc.selectNodes("/bookstore/book[0]")

If you have IE 5 or higher you can try it yourself.

Note: IE 5 and 6 has implemented that [0] should be the first node, but according to the W3C standard it should have been [1]!!

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Select the prices
選擇prices

The following example selects the text from all the price nodes:

xmlDoc.selectNodes("/bookstore/book/price/text()") 

If you have IE 5 or higher you can try it yourself.

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Selecting price Nodes with Price>35
選擇price大於35的price節點

The following example selects all the price nodes with a price higher than 35:

xmlDoc.selectNodes("/bookstore/book[price>35]/price") 

If you have IE 5 or higher you can try it yourself.

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Selecting title Nodes with Price>35
選擇Price大於35的title節點

The following example selects all the title nodes with a price higher than 35:

xmlDoc.selectNodes("/bookstore/book[price>35]/title")