SQL Server 2005 XML 操作总结（五）元素（节点）操作——修改、删除、移动、遍历操作

========修改操作======

--将category="WEB"的第一个book节点的year值改为2000
set @data.modify('replace value of
(/bookstore/book[@category="WEB"]/year/text())[1] with "2000"')
/*output:
<book category="WEB">
<title lang="cn">Learning XML</title>
<author>Erik T. Ray</author>
<year>2000</year>
<price>39.95</price>
</book>
*/
--替换第一个book节点的author的内容为“替换内容”
set @data.modify('replace value of(/bookstore/book[1]/author[1]/text())[1] with ("替换内容")')
/*output:
<book category="COOKING">
<title lang="en">Everyday Italian</title>
<author>替换内容</author>
<year>2005</year>
<price>30.00</price>
</book>*/

========删除操作========

--删除title的@lang="en"的所有book节点
set @data.modify('delete /bookstore/book[./title[@lang="en"]]')
/*output:
<bookstore>
<book>
<title lang="jp">Harry Potter</title>
<author>J K. Rowling</author>
<year>2005</year>
<price>29.99</price>
</book>
<book category="WEB">
<title lang="cn">Learning XML</title>
<author>Erik T. Ray</author>
<year>2003</year>
<price>39.95</price>
</book>
</bookstore>
*/
--删除第一个book节点的author的内容
set @data.modify('delete /bookstore[1]/book[1]/author[1]/text()')
/*output:
<book category="COOKING">
<title lang="en">Everyday Italian</title>
<author />
<year>2005</year>
<price>30.00</price>
</book>
*/
========移动操作=========

--title="Harry Potter"的book节点在同级中上移一层
set @data.modify('insert (/bookstore/book[title="Harry Potter"])
before (/bookstore/book[. << (/bookstore/book[title="Harry Potter"])[1]])
[last()]')
SET @data.modify ('delete  /bookstore/book[title="Harry Potter"]
[. is (/bookstore/book[title="Harry Potter"])[last()]]')
/*output:
<book category="CHILDREN">
......
</book>
<book category="COOKING">
......
</book>
<book category="WEB">
......
</book>
<book category="WEB">
......
</book>*/
--title="Harry Potter"的book节点在同级中下移一层
set @data.modify('insert (/bookstore/book[title="Harry Potter"])
before (/bookstore/book[. >> (/bookstore/book[title="Harry Potter"])[1]])
[last()]')
SET @data.modify ('delete  /bookstore/book[title="Harry Potter"][1] ')
/*output:
<book category="COOKING">
......
</book>
<book category="WEB">
......
</book>
<book category="CHILDREN">
......
</book>
<book category="WEB">
......
</book>*/
--title="Harry Potter"的book节点移到category为COOKING的book节点前
set @data.modify('insert (/bookstore/book[title="Harry Potter"])
before (/bookstore/book[@category="COOKING"])[1]')
SET @data.modify ('delete  /bookstore/book[title="Harry Potter"] [2]')
/*output:
<book category="CHILDREN">
......
</book>
<book category="COOKING">
......
</book>
<book category="WEB">
......
</book>
<book category="WEB">
......
</book>*/
--title="Harry Potter"的book节点移到categroy为WEB的第一个book节点后
set @data.modify('insert (/bookstore/book[title="Harry Potter"])
after (/bookstore/book[@category="WEB"])[1] ')
SET @data.modify ('delete  /bookstore/book[title="Harry Potter"][1] ')
/*output:
<book category="COOKING">
......
</book>
<book category="WEB">
......
</book>
<book category="CHILDREN">
......
</book>
<book category="WEB">
......
</book>*/

========循环遍历所有元素=========

--循环所有book节点
DECLARE
@cnt INT,
@totCnt INT,
@child XML
-- counter variables
SELECT
@cnt = 1,
@totCnt = @data.value('count(/bookstore/book)','INT')
-- loop
WHILE @cnt <= @totCnt BEGIN
SELECT
@child = @data.query('/bookstore/book[position()=sql:variable("@cnt")]')
PRINT 'Processing Child Element: ' + CAST(@cnt AS VARCHAR)
PRINT 'Child element:  ' + CAST(@child AS VARCHAR(max))
PRINT ''
-- incremet the counter variable
SELECT @cnt = @cnt + 1
END
/*output
Processing Child Element: 1
Child element:  <book category="COOKING">......</book>

Processing Child Element: 2
Child element:  <book><title lang="jp">......</book>

Processing Child Element: 3
Child element:  <book category="WEB">......</book>

Processing Child Element: 4
Child element:  <book category="WEB">......</book>