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、delete。
SQL 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 = ‘
‘
1.XML.Modify(Insert)语句介绍
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
)
set
@XMLVar.modify
(
‘insert
)
set
@XMLVar.modify
(
‘insert
)
set
@XMLVar.modify
(
‘insert
)
SELECT
@XMLVar.query(‘/catalog[1]/book[1]’
);
结果集为:
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’
SET @XMLVar.modify(‘
)
insert sql:variable(“@newFeatures”)
into (/catalog[1]/book[1])’
–方法二:直接插入
set @XMLVar.modify(‘
)
insert (
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:
>
2:
3:
>Bill Zack
4:
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(
‘insert
)
before (/catalog[1]/book[1]/title[1])’
SELECT @XMLVar.query(‘/catalog[1]/book[1]’
);
结果集为:
1:
2:
3:
4:
5:
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
)
before (/catalog[1]/book[1]/title[1])’
SELECT @XMLVar.query(‘/catalog[1]/book[1]’
);
结果集为:
1:
2:
3:
4:
5:
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:
2:
3:
4:
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:
2:
3:
4:
6:
7:
8:
9:
11:
3.XML.Modify(replace)语句介绍
–替换属性
set @XMLVar.modify(‘replace value of(/catalog[1]/book[1]/@category))
with (“替换属性”)’
–替换内容
set @XMLVar.modify(‘replace value of(/catalog[1]/book[1]/author[1]/text()[1]))
with(“替换内容”)’
–条件替换
set @XMLVar.modify(‘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]’
);
结果集为:
1:
2:
3:
4:
5:
7:
8:
Developing ADO .NET
9:
Andrew Brust
10:
12:
13:
14:
15:
17: