SQL Server 2005/2008增加了对XML数据的支持,同时也新增了几种操作XML的方法,本文主要以SQL Server 2008为例介绍如何对XML数据进行insert、update、deleteSQL
Server中新增加了XML.Modify()方法,分别为xml.modify(insert),xml.modify(delete),xml.modify(replace)对应XML的插入,删除和修改操作。
本文以下面XML为例,对三种DML进行说明:
- declare @XMLVar XML;
- SET @XMLVar= '
- <catalog>
- <book category="ITPro">
- <title>Windows Step By Step</title>
- <author>Bill Zack</author>
- <price>49.99</price>
- </book>
- <book category="Developer">
- <title>Developing ADO .NET</title>
- <author>Andrew Brust</author>
- <price>39.93</price>
- </book>
- <book category="ITPro">
- <title>Windows Cluster Server</title>
- <author>Stephen Forte</author>
- <price>59.99</price>
- </book>
- </catalog>
A.利用as first,at last,before,after四个参数将元素插入指定的位置
- set @XMLVar.modify(
- 'insert <first name="at first" /> as first into (/catalog[1]/book[1])')
- set @XMLVar.modify(
- 'insert <last name="at last"/> as last into (/catalog[1]/book[1])')
- set @XMLVar.modify(
- 'insert <before name="before"/> before (/catalog[1]/book[1]/author[1])')
- set @XMLVar.modify(
- 'insert <after name="after"/> after (/catalog[1]/book[1]/author[1])')
- SELECT @XMLVar.query('/catalog[1]/book[1]');
结果集为:
- 1: <book category="ITPro">
- 2: <first name="at first" />
- 3: <title>Windows Step By Step</title>
- 4: <before name="before" />
- 5: <author>Bill Zack</author>
- 6: <after name="after" />
- 7: <price>49.99</price>
- 8: <last name="at last" />
- 9: </book>
B.将多个元素插入文档中
- --方法一:利用变量进行插入
- DECLARE @newFeatures xml;
- SET @newFeatures = N'; <first>one element</first> <second>second element</second>'
- SET @XMLVar.modify(' )
- insert sql:variable("@newFeatures")
- into (/catalog[1]/book[1])'
- --方法二:直接插入
- set @XMLVar.modify(')
- insert (<first>one element</first>,<second>second element</second>)
- into (/catalog[1]/book[1]/author[1])'
- SELECT @XMLVar.query('/catalog[1]/book[1]');
结果集为:
- 1: <book category="ITPro">
- 2: <title>Windows Step By Step</title>
- 3: <author>Bill Zack
- 4: <first>one element</first>
- 5: <second>second element</second>
- 6: </author>
- 7: <price>49.99</price>
- 8: <first>one element</first>
- 9: <second>second element</second>
- 10: </book>
C.将属性插入文档中
- --使用变量插入
- declare @var nvarchar(10) = '变量插入'
- set @XMLVar.modify(
- 'insert (attribute var {sql:variable("@var")}))
- into (/catalog[1]/book[1])'
- --直接插入
- set @XMLVar.modify(
- 'insert (attribute name {"直接插入"}))
- into (/catalog[1]/book[1]/title[1])'
- --多值插入
- set @XMLVar.modify(
- 'insert (attribute Id {"多值插入1"},attribute name {"多值插入2"}) )
- into (/catalog[1]/book[1]/author[1])'
- SELECT @XMLVar.query('/catalog[1]/book[1]');
结果集为:
- 1: <book category="ITPro" var="变量插入">
- 2: <title name="直接插入">Windows Step By Step</title>
- 3: <author Id="多值插入1" name="多值插入2">Bill Zack</author>
- 4: <price>49.99</price>
- 5: </book>
D.插入文本节点
- set @XMLVar.modify(
- 'insert text{"at first"} as first)
- into (/catalog[1]/book[1])'
- SELECT @XMLVar.query('/catalog[1]/book[1]');
结果集为:
- 1: <book category="ITPro">
- 2: at first
- 3: <title>Windows Step By Step</title>
- 4: <author>Bill Zack</author>
- 5: <price>49.99</price>
- 6: </book>
注意:插入本文同样具体 as first,as last,before,after四种选项,可以参考A中的使用方法
E.插入注释节点
- set @XMLVar.modify(
- N'insert <!--插入评论-->
- before (/catalog[1]/book[1]/title[1])' )
- SELECT @XMLVar.query('/catalog[1]/book[1]');
结果集为:
1: <book category="ITPro">
2: <!--插入评论-->
3: <title>Windows Step By Step</title>
4: <author>Bill Zack</author>
5: <price>49.99</price>
6: </book>
注意插入注释节点同样具体 as first,as last,before,after四种选项,可以参考A中的使用方法
F.插入处理指令
- set @XMLVar.modify(
- 'insert <?Program "Instructions.exe" ?>
- before (/catalog[1]/book[1]/title[1])' )
- SELECT @XMLVar.query('/catalog[1]/book[1]');
结果集为:
1: <book category="ITPro">
2: <?Program "Instructions.exe" ?>
3: <title>Windows Step By Step</title>
4: <author>Bill Zack</author>
5: <price>49.99</price>
6: </book>
注意插入处理指令同样具体 as first,as last,before,after四种选项,可以参考A中的使用方法
G.根据 if 条件语句进行插入
- set @XMLVar.modify(
- 'insert
- if (/catalog[1]/book[1]/title[2]) then
- text{"this is a 1 step"}
- else ( text{"this is a 2 step"} )
- into (/catalog[1]/book[1]/price[1])' )
- SELECT @XMLVar.query('/catalog[1]/book[1]');
结果集为:
1: <book category="ITPro">
2: <title>Windows Step By Step</title>
3: <author>Bill Zack</author>
4: <price>49.99this is a 2 step</price>
5: </book>
2.XML.Modify(delete)语句介绍
- --删除属性
- set @XMLVar.modify('delete /catalog[1]/book[1]/@category')
- --删除节点
- set @XMLVar.modify('delete /catalog[1]/book[1]/title[1]')
- --删除内容
- set @XMLVar.modify('delete /catalog[1]/book[1]/author[1]/text()')
- --全部删除
- set @XMLVar.modify('delete /catalog[1]/book[2]')
- SELECT @XMLVar.query('/catalog[1]');
结果集为:
- 1: <catalog>
- 2: <book>
- 3: <author />
- 4: <price>49.99</price>
- 5: </book>
- 6: <book category="ITPro">
- 7: <title>Windows Cluster Server</title>
- 8: <author>Stephen Forte</author>
- 9: <price>59.99</price>
- 10: </book>
- 11: </catalog>
3.XML.Modify(replace)语句介绍
- --替换属性
- set @XMLVar.modify(N'replace value of(/catalog[1]/book[1]/@category)
- with ("替换属性")' )
- --替换内容
- set @XMLVar.modify(N'replace value of(/catalog[1]/book[1]/author[1]/text()[1])
- with("替换内容")' )
- --条件替换
- set @XMLVar.modify(N'replace value of (/catalog[1]/book[2]/@category)
- with(
- if(count(/catalog[1]/book)>4) then
- "条件替换1"
- else
- "条件替换2")' )
- SELECT @XMLVar.query('/catalog[1]');
- [code]
- 结果集为:
- [code]
- 1: <catalog>
- 2: <book category="替换属性">
- 3: <title>Windows Step By Step</title>
- 4: <author>替换内容</author>
- 5: <price>49.99</price>
- 6: </book>
- 7: <book category="条件替换2">
- 8: <title>Developing ADO .NET</title>
- 9: <author>Andrew Brust</author>
- 10: <price>39.93</price>
- 11: </book>
- 12: <book category="ITPro">
- 13: <title>Windows Cluster Server</title>
- 14: <author>Stephen Forte</author>
- 15: <price>59.99</price>
- 16: </book>
- 17: </catalog>