SQL Server解析XML数据的方法详解

时间：2023-11-09 19:21:50
--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,'/*/*/*'

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