本文实例讲述了SQL Server解析XML数据的方法。分享给大家供大家参考，具体如下：
--5.读取XML
--下面为多种方法从XML中读取EMAIL
DECLARE @x XML
SELECT @x = \'
<People>
<dongsheng>
<Info Name=\"Email\">dongsheng@xxyy.com</Info>
<Info Name=\"Phone\">678945546</Info>
<Info Name=\"qq\">36575</Info>
</dongsheng>
</People>\'
-- 方法1
SELECT @x.value(\'data(/People/dongsheng/Info[@Name=\"Email\"])[1]\', \'varchar(30)\')
-- 方法2
SELECT @x.value(\'(/People/dongsheng/Info[@Name=\"Email\"])[1]\', \'varchar(30)\')
-- 方法3
SELECT
C.value(\'.\',\'varchar(30)\')
FROM @x.nodes(\'/People/dongsheng/Info[@Name=\"Email\"]\') T(C)
-- 方法4
SELECT
C.value(\'(Info[@Name=\"Email\"])[1]\',\'varchar(30)\')
FROM @x.nodes(\'/People/dongsheng\') T(C)
-- 方法5
SELECT
C.value(\'(dongsheng/Info[@Name=\"Email\"])[1]\',\'varchar(30)\')
FROM @x.nodes(\'/People\') T(C)
-- 方法6
SELECT
C.value(\'.\',\'varchar(30)\')
FROM @x.nodes(\'/People/dongsheng/Info\') T(C)
WHERE C.value(\'(.[@Name=\"Email\"])[1]\',\'varchar(30)\') IS NOT NULL
-- 方法7
SELECT
C.value(\'.\',\'varchar(30)\')
FROM @x.nodes(\'/People/dongsheng/Info\') T(C)
WHERE C.exist(\'(.[@Name=\"Email\"])[1]\') = 1
--6.Reading values from an XML variable
DECLARE @x XML
SELECT @x =
\'<Peoples>
<People Name=\"tudou\" Sex=\"女\" />
<People Name=\"choushuigou\" Sex=\"女\"/>
<People Name=\"dongsheng\" Sex=\"男\" />
</Peoples>\'
SELECT
v.value(\'@Name[1]\',\'VARCHAR(20)\') AS Name,
v.value(\'@Sex[1]\',\'VARCHAR(20)\') AS Sex
FROM @x.nodes(\'/Peoples/People\') x(v)
--7.多属性过滤
DECLARE @x XML
SELECT @x = \'
<Employees>
<Employee id=\"1234\" dept=\"IT\" type=\"合同工\">
<Info NAME=\"dongsheng\" SEX=\"男\" QQ=\"5454545454\"/>
</Employee>
<Employee id=\"5656\" dept=\"IT\" type=\"临时工\">
<Info NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\"/>
</Employee>
<Employee id=\"3242\" dept=\"市场\" type=\"合同工\">
<Info NAME=\"choushuigou\" SEX=\"女\" QQ=\"54543545\"/>
</Employee>
</Employees>\'
--查询dept为IT的人员信息
--方法1
SELECT
C.value(\'@NAME[1]\',\'VARCHAR(10)\') AS NAME,
C.value(\'@SEX[1]\',\'VARCHAR(10)\') AS SEX,
C.value(\'@QQ[1]\',\'VARCHAR(20)\') AS QQ
FROM @x.nodes(\'/Employees/Employee[@dept=\"IT\"]/Info\') T(C)
/*
NAME SEX QQ
---------- ---------- --------------------
dongsheng 男 5454545454
土豆 女 5345454554
*/
--方法2
SELECT
C.value(\'@NAME[1]\',\'VARCHAR(10)\') AS NAME,
C.value(\'@SEX[1]\',\'VARCHAR(10)\') AS SEX,
C.value(\'@QQ[1]\',\'VARCHAR(20)\') AS QQ
FROM @x.nodes(\'//Employee[@dept=\"IT\"]/*\') T(C)
/*
NAME SEX QQ
---------- ---------- --------------------
dongsheng 男 5454545454
土豆 女 5345454554
*/
--查询出IT部门type为Permanent的员工
SELECT
C.value(\'@NAME[1]\',\'VARCHAR(10)\') AS NAME,
C.value(\'@SEX[1]\',\'VARCHAR(10)\') AS SEX,
C.value(\'@QQ[1]\',\'VARCHAR(20)\') AS QQ
FROM @x.nodes(\'//Employee[@dept=\"IT\"][@type=\"合同工\"]/*\') T(C)
/*
NAME SEX QQ
---------- ---------- --------------------
dongsheng 男 5454545454
*/
--12.从XML变量中删除元素
DECLARE @x XML
SELECT @x = \'
<Peoples>
<People>
<NAME>土豆</NAME>
<SEX>男</SEX>
<QQ>5345454554</QQ>
</People>
</Peoples>\'
SET @x.modify(\'
delete (/Peoples/People/SEX)[1]\'
)
SELECT @x
/*
<Peoples>
<People>
<NAME>土豆</NAME>
<QQ>5345454554</QQ>
</People>
</Peoples>
*/
--19.读取指定变量元素的值
DECLARE @x XML
SELECT @x = \'
<Peoples>
<People>
<NAME>dongsheng</NAME>
<SEX>男</SEX>
<QQ>423545</QQ>
</People>
<People>
<NAME>土豆</NAME>
<SEX>男</SEX>
<QQ>123133</QQ>
</People>
<People>
<NAME>choushuigou</NAME>
<SEX>女</SEX>
<QQ>54543545</QQ>
</People>
</Peoples>
\'
DECLARE @ElementName VARCHAR(20)
SELECT @ElementName = \'NAME\'
SELECT c.value(\'.\',\'VARCHAR(20)\') AS NAME
FROM @x.nodes(\'/Peoples/People/*[local-name()=sql:variable(\"@ElementName\")]\') T(C)
/*
NAME
--------------------
dongsheng
土豆
choushuigou
*/
--20使用通配符读取元素值
--读取根元素的值
DECLARE @x1 XML
SELECT @x1 = \'<People>dongsheng</People>\'
SELECT @x1.value(\'(/*/text())[1]\',\'VARCHAR(20)\') AS People --星号*代表一个元素
/*
People
--------------------
dongsheng
*/
--读取第二层元素的值
DECLARE @x XML
SELECT @x = \'
<People>
<NAME>dongsheng</NAME>
<SEX>男</SEX>
<QQ>423545</QQ>
</People>\'
SELECT
@x.value(\'(/*/*/text())[1]\',\'VARCHAR(20)\') AS NAME
/*
NAME
--------------------
dongsheng
*/
--读取第二个子元素的值
DECLARE @x XML
SELECT @x = \'
<People>
<NAME>dongsheng</NAME>
<SEX>男</SEX>
<QQ>423545</QQ>
</People>\'
SELECT
@x.value(\'(/*/*/text())[2]\',\'VARCHAR(20)\') AS SEX
/*
SEX
--------------------
男
*/
--读取所有第二层子元素值
DECLARE @x XML
SELECT @x = \'
<People>
<NAME>dongsheng</NAME>
<SEX>男</SEX>
<QQ>423545</QQ>
</People>\'
SELECT
C.value(\'.\',\'VARCHAR(20)\') AS value
FROM @x.nodes(\'/*/*\') T(C)
/*
value
--------------------
dongsheng
男
423545
*/
--21.使用通配符读取元素名称
DECLARE @x XML
SELECT @x = \'<People>dongsheng</People>\'
SELECT
@x.value(\'local-name(/*[1])\',\'VARCHAR(20)\') AS ElementName
/*
ElementName
--------------------
People
*/
--读取根下第一个元素的名称和值
DECLARE @x XML
SELECT @x = \'
<People>
<NAME>dongsheng</NAME>
<SEX>男</SEX>
</People>\'
SELECT
@x.value(\'local-name((/*/*)[1])\',\'VARCHAR(20)\') AS ElementName,
@x.value(\'(/*/*/text())[1]\',\'VARCHAR(20)\') AS ElementValue
/*
ElementName ElementValue
-------------------- --------------------
NAME dongsheng
*/
--读取根下第二个元素的名称和值
DECLARE @x XML
SELECT @x = \'
<People>
<NAME>dongsheng</NAME>
<SEX>男</SEX>
</People>\'
SELECT
@x.value(\'local-name((/*/*)[2])\',\'VARCHAR(20)\') AS ElementName,
@x.value(\'(/*/*/text())[2]\',\'VARCHAR(20)\') AS ElementValue
/*
ElementName ElementValue
-------------------- --------------------
SEX 男
*/
--读取根下所有的元素名称和值
DECLARE @x XML
SELECT @x = \'
<People>
<NAME>dongsheng</NAME>
<SEX>男</SEX>
</People>\'
SELECT
C.value(\'local-name(.)\',\'VARCHAR(20)\') AS ElementName,
C.value(\'.\',\'VARCHAR(20)\') AS ElementValue
FROM @x.nodes(\'/*/*\') T(C)
/*
ElementName ElementValue
-------------------- --------------------
NAME dongsheng
SEX 男
*/
---22.查询元素数量
--如下Peoples根节点下有个People子节点。
DECLARE @x XML
SELECT @x = \'
<Peoples>
<People>
<NAME>dongsheng</NAME>
<SEX>男</SEX>
</People>
<People>
<NAME>土豆</NAME>
<SEX>男</SEX>
</People>
<People>
<NAME>choushuigou</NAME>
<SEX>女</SEX>
</People>
</Peoples>
\'
SELECT @x.value(\'count(/Peoples/People)\',\'INT\') AS Children
/*
Children
-----------
3
*/
--如下Peoples根节点下第一个子节点People下子节点的数量
SELECT @x.value(\'count(/Peoples/People[1]/*)\',\'INT\') AS Children
/*
Children
-----------
2
*/
--某些时候我们可能不知道根节点和子节点的名称，可以用通配符来代替。
SELECT @x.value(\'count(/*/*)\',\'INT\') AS ChildrenOfRoot,
@x.value(\'count(/*/*[1]/*)\',\'INT\') AS ChildrenOfFirstChildElement
/*
ChildrenOfRoot ChildrenOfFirstChildElement
-------------- ---------------------------
3 2
*/
--23.查询属性的数量
DECLARE @x XML
SELECT @x = \'
<Employees dept=\"IT\">
<Employee NAME=\"dongsheng\" SEX=\"男\" QQ=\"5454545454\"/>
<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\"/>
</Employees>\'
--查询跟节点的属性数量
SELECT @x.value(\'count(/Employees/@*)\',\'INT\') AS AttributeCountOfRoot
/*
AttributeCountOfRoot
--------------------
1
*/
--第一个Employee节点的属性数量
SELECT @x.value(\'count(/Employees/Employee[1]/@*)\',\'INT\') AS AttributeCountOfFirstElement
/*
AttributeCountOfFirstElement
----------------------------
3
*/
--第二个Employee节点的属性数量
SELECT @x.value(\'count(/Employees/Employee[2]/@*)\',\'INT\') AS AttributeCountOfSeconfElement
/*
AttributeCountOfSeconfElement
-----------------------------
4
*/
--如果不清楚节点名称可以用*通配符代替
SELECT @x.value(\'count(/*/@*)\',\'INT\') AS AttributeCountOfRoot
,@x.value(\'count(/*/*[1]/@*)\',\'INT\') AS AttributeCountOfFirstElement
,@x.value(\'count(/*/*[2]/@*)\',\'INT\') AS AttributeCountOfSeconfElement
/*
AttributeCountOfRoot AttributeCountOfFirstElement AttributeCountOfSeconfElement
-------------------- ---------------------------- -----------------------------
1 3 4
*/
--返回没个节点的属性值
SELECT C.value(\'count(./@*)\',\'INT\') AS AttributeCount
FROM @x.nodes(\'/*/*\') T(C)
/*
AttributeCount
--------------
3
4
*/
--24.返回给定位置的属性值或者名称
DECLARE @x XML
SELECT @x = \'
<Employees dept=\"IT\">
<Employee NAME=\"dongsheng\" SEX=\"男\" QQ=\"5454545454\"/>
<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\"/>
</Employees>\'
--返回第一个Employee节点的第一个位置的属性值
SELECT @x.value(\'(/Employees/Employee[1]/@*[position()=1])[1]\',\'VARCHAR(20)\') AS AttValue
/*
AttValue
--------------------
dongsheng
*/
--返回第二个Employee节点的第四个位置的属性值
SELECT @x.value(\'(/Employees/Employee[2]/@*[position()=4])[1]\',\'VARCHAR(20)\') AS AttValue
/*
AttValue
--------------------
13954697895
*/
--返回第一个元素的第三个属性值
SELECT @x.value(\'local-name((/Employees/Employee[1]/@*[position()=3])[1])\',\'VARCHAR(20)\') AS AttName
/*
AttName
--------------------
QQ
*/
--返回第二个元素的第四个属性值
SELECT @x.value(\'local-name((/Employees/Employee[2]/@*[position()=4])[1])\',\'VARCHAR(20)\') AS AttName
/*
AttName
--------------------
TEL
*/
--通过变量传递位置返回属性值
DECLARE @Elepos INT,@Attpos INT
SELECT @Elepos=2,@Attpos = 3
SELECT @x.value(\'local-name((/Employees/Employee[sql:variable(\"@Elepos\")]/@*[position()=sql:variable(\"@Attpos\")])[1])\',\'VARCHAR(20)\') AS AttName
/*
AttName
--------------------
QQ
*/
--25.判断是XML中否存在相应的属性
DECLARE @x XML
SELECT @x = \'<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\"/>\'
IF @x.exist(\'/Employee/@NAME\') = 1
SELECT \'Exists\' AS Result
ELSE
SELECT \'Does not exist\' AS Result
/*
Result
------
Exists
*/
--传递变量判断是否存在
DECLARE @x XML
SELECT @x = \'<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\"/>\'
DECLARE @att VARCHAR(20)
SELECT @att = \'QQ\'
IF @x.exist(\'/Employee/@*[local-name()=sql:variable(\"@att\")]\') = 1
SELECT \'Exists\' AS Result
ELSE
SELECT \'Does not exist\' AS Result
/*
Result
------
Exists
*/
--26.循环遍历元素的所有属性
DECLARE @x XML
SELECT @x = \'<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\"/>\'
DECLARE
@cnt INT,
@totCnt INT,
@attName VARCHAR(30),
@attValue VARCHAR(30)
SELECT
@cnt = 1,
@totCnt = @x.value(\'count(/Employee/@*)\',\'INT\')--获得属性总数量
-- loop
WHILE @cnt <= @totCnt BEGIN
SELECT
@attName = @x.value(
\'local-name((/Employee/@*[position()=sql:variable(\"@cnt\")])[1])\',
\'VARCHAR(30)\'),
@attValue = @x.value(
\'(/Employee/@*[position()=sql:variable(\"@cnt\")])[1]\',
\'VARCHAR(30)\')
PRINT \'Attribute Position: \' + CAST(@cnt AS VARCHAR)
PRINT \'Attribute Name: \' + @attName
PRINT \'Attribute Value: \' + @attValue
PRINT \'\'
-- increment the counter variable
SELECT @cnt = @cnt + 1
END
/*
Attribute Position: 1
Attribute Name: NAME
Attribute Value: 土豆
Attribute Position: 2
Attribute Name: SEX
Attribute Value: 女
Attribute Position: 3
Attribute Name: QQ
Attribute Value: 5345454554
Attribute Position: 4
Attribute Name: TEL
Attribute Value: 13954697895
*/
--27.返回指定位置的子元素
DECLARE @x XML
SELECT @x = \'
<Employees dept=\"IT\">
<Employee NAME=\"dongsheng\" SEX=\"男\" QQ=\"5454545454\"/>
<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\"/>
</Employees>\'
SELECT @x.query(\'(/Employees/Employee)[1]\')
/*
<Employee NAME=\"dongsheng\" SEX=\"男\" QQ=\"5454545454\" />
*/
SELECT @x.query(\'(/Employees/Employee)[position()=2]\')
/*
<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\" />
*/
--通过变量获取指定位置的子元素
DECLARE @i INT
SELECT @i = 2
SELECT @x.query(\'(/Employees/Employee)[sql:variable(\"@i\")]\')
--or
SELECT @x.query(\'(/Employees/Employee)[position()=sql:variable(\"@i\")]\')
/*
<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\" />
*/
--28.循环遍历获得所有子元素
DECLARE @x XML
SELECT @x = \'
<Employees dept=\"IT\">
<Employee NAME=\"dongsheng\" SEX=\"男\" QQ=\"5454545454\"/>
<Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\"/>
</Employees>\'
DECLARE
@cnt INT,
@totCnt INT,
@child XML
-- counter variables
SELECT
@cnt = 1,
@totCnt = @x.value(\'count(/Employees/Employee)\',\'INT\')
-- loop
WHILE @cnt <= @totCnt BEGIN
SELECT
@child = @x.query(\'/Employees/Employee[position()=sql:variable(\"@cnt\")]\')
PRINT \'Processing Child Element: \' + CAST(@cnt AS VARCHAR)
PRINT \'Child element: \' + CAST(@child AS VARCHAR(100))
PRINT \'\'
-- incremet the counter variable
SELECT @cnt = @cnt + 1
END
/*
Processing Child Element: 1
Child element: <Employee NAME=\"dongsheng\" SEX=\"男\" QQ=\"5454545454\"/>
Processing Child Element: 2
Child element: <Employee NAME=\"土豆\" SEX=\"女\" QQ=\"5345454554\" TEL=\"13954697895\"/>
SQL Server 中对XML数据的五种基本操作
1.xml.exist
输入为XQuery表达式，返回0，1或是Null。0表示不存在，1表示存在，Null表示输入为空
2.xml.value
输入为XQuery表达式，返回一个SQL Server标量值
3.xml.query
输入为XQuery表达式，返回一个SQL Server XML类型流
4.xml.nodes
输入为XQuery表达式，返回一个XML格式文档的一列行集
5.xml.modify
使用XQuery表达式对XML的节点进行insert , update 和 delete 操作。
下面通过例子对上面的五种操作进行说明：
declare @XMLVar xml = \'
<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>\'
1. xml.exist
select @XMLVar.exist(\'/catalog/book\')-----返回1 select @XMLVar.exist(\'/catalog/book/@category\')-----返回1 select @XMLVar.exist(\'/catalog/book1\')-----返回0 set @XMLVar = null select @XMLVar.exist(\'/catalog/book\')-----返回null
2.xml.value
select @XMLVar.value(\'/catalog[1]/book[1]\',\'varchar(MAX)\') select @XMLVar.value(\'/catalog[1]/book[2]/@category\',\'varchar(MAX)\') select @XMLVar.value(\'/catalog[2]/book[1]\',\'varchar(MAX)\')
结果集为：
Windows Step By StepBill Zack49.99 Developer NULL
3.xml.query
select @XMLVar.query(\'/catalog[1]/book\') select @XMLVar.query(\'/catalog[1]/book[1]\') select @XMLVar.query(\'/catalog[1]/book[2]/author\')
结果集分别为：
<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> <book category=\"ITPro\"> <title>Windows Step By Step</title> <author>Bill Zack</author> <price>49.99</price> </book> <author>Andrew Brust</author>
4.xml.nodes
select T.c.query(\'.\') as result from @XMLVar.nodes(\'/catalog/book\') as T(c) select T.c.query(\'title\') as result from @XMLVar.nodes(\'/catalog/book\') as T(c)
结果集分别为：
<book category=\"ITPro\"><title>Windows Step By Step</title><author>Bill ………… <book category=\"Developer\"><title>Developing ADO .NET</title><author>Andrew ………… <book category=\"ITPro\"><title>Windows Cluster Server</title><author>Stephen ………… <title>Windows Step By Step</title> <title>Developing ADO .NET</title> <title>Windows Cluster Server</title>
set ARITHABORT on
DECLARE @x XML
SELECT @x = \'<Peoples>
<People>
<Email>1dongsheng@xxyy.com</Email>
<Phone>678945546</Phone>
<QQ>36575</QQ>
<Addr>36575</Addr>
</People>
</Peoples>\'
-- 方法1
select 1001 as peopleId, p.* FROM(
SELECT
C.value(\'local-name(.)\',\'VARCHAR(20)\') AS attrName,
C.value(\'.\',\'VARCHAR(20)\') AS attrValue
FROM @x.nodes(\'/*/*/*\') T(C) --第三层
) as p
/*
1001 Email 1dongsheng@xxyy.com
1001 Phone 678945546
1001 QQ 36575
1001 Addr 36575
*/
/*
解析XML存储过程
*/
ALTER PROCEDURE [dbo].[sp_ExportXml]
@x xml ,
@layerstr nvarchar(max)
AS
DECLARE @sql nvarchar(max)
BEGIN
set arithabort on
set @sql=\'select p.* FROM(
SELECT
C.value(\'\'local-name(.)\'\',\'\'VARCHAR(20)\'\') AS attrName,
C.value(\'\'.\'\',\'\'VARCHAR(20)\'\') AS attrValue
FROM @xmlParas.nodes(\'\'\'+@layerstr+\'\'\') T(C)
) as p\'
--print @sql
EXECUTE sp_executesql @sql, N\'@xmlParas as xml\',@xmlParas=@x
END
DECLARE @x XML
SELECT @x =
\'<Peoples>
<People>
<Email>1dongsheng@xxyy.com</Email>
<Phone>678945546</Phone>
<QQ>36575</QQ>
<Addr>36575</Addr>
</People>
</Peoples>\'
EXECUTE sp_ExportXml @x,\'/*/*/*\'
希望本文所述对大家SQL Server数据库程序设计有所帮助。
