本文實例講述了SQL Server解析XML數據的方法。分享給大家供大家參考，具體如下：
--5.讀取XML
--下面為多種方法從XML中讀取EMAIL
DECLARE @x XML
SELECT @x = '
<People>
<dongsheng>
<Info Name="Email">[email protected]</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.多屬性過濾
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="臨時工">
<Info NAME="土豆" SEX="女" QQ="5345454554"/>
</Employee>
<Employee id="3242" dept="市場" type="合同工">
<Info NAME="choushuigou" SEX="女" QQ="54543545"/>
</Employee>
</Employees>'
--查詢dept為IT的人員信息
--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
*/
--查詢出IT部門type為Permanent的員工
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.從XML變量中刪除元素
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.讀取指定變量元素的值
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使用通配符讀取元素值
--讀取根元素的值
DECLARE @x1 XML
SELECT @x1 = '<People>dongsheng</People>'
SELECT @x1.value('(/*/text())[1]','VARCHAR(20)') AS People --星號*代表一個元素
/*
People
--------------------
dongsheng
*/
--讀取第二層元素的值
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
*/
--讀取第二個子元素的值
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
*/
--讀取所有第二層子元素值
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.使用通配符讀取元素名稱
DECLARE @x XML
SELECT @x = '<People>dongsheng</People>'
SELECT
@x.value('local-name(/*[1])','VARCHAR(20)') AS ElementName
/*
ElementName
--------------------
People
*/
--讀取根下第一個元素的名稱和值
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
*/
--讀取根下第二個元素的名稱和值
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
*/
--讀取根下所有的元素名稱和值
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.查詢元素數量
--如下Peoples根節點下有個People子節點。
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根節點下第一個子節點People下子節點的數量
SELECT @x.value('count(/Peoples/People[1]/*)','INT') AS Children
/*
Children
-----------
2
*/
--某些時候我們可能不知道根節點和子節點的名稱，可以用通配符來代替。
SELECT @x.value('count(/*/*)','INT') AS ChildrenOfRoot,
@x.value('count(/*/*[1]/*)','INT') AS ChildrenOfFirstChildElement
/*
ChildrenOfRoot ChildrenOfFirstChildElement
-------------- ---------------------------
3 2
*/
--23.查詢屬性的數量
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>'
--查詢跟節點的屬性數量
SELECT @x.value('count(/Employees/@*)','INT') AS AttributeCountOfRoot
/*
AttributeCountOfRoot
--------------------
1
*/
--第一個Employee節點的屬性數量
SELECT @x.value('count(/Employees/Employee[1]/@*)','INT') AS AttributeCountOfFirstElement
/*
AttributeCountOfFirstElement
----------------------------
3
*/
--第二個Employee節點的屬性數量
SELECT @x.value('count(/Employees/Employee[2]/@*)','INT') AS AttributeCountOfSeconfElement
/*
AttributeCountOfSeconfElement
-----------------------------
4
*/
--如果不清楚節點名稱可以用*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
*/
--返回沒個節點的屬性值
SELECT C.value('count(./@*)','INT') AS AttributeCount
FROM @x.nodes('/*/*') T(C)
/*
AttributeCount
--------------
3
4
*/
--24.返回給定位置的屬性值或者名稱
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>'
--返回第一個Employee節點的第一個位置的屬性值
SELECT @x.value('(/Employees/Employee[1]/@*[position()=1])[1]','VARCHAR(20)') AS AttValue
/*
AttValue
--------------------
dongsheng
*/
--返回第二個Employee節點的第四個位置的屬性值
SELECT @x.value('(/Employees/Employee[2]/@*[position()=4])[1]','VARCHAR(20)') AS AttValue
/*
AttValue
--------------------
13954697895
*/
--返回第一個元素的第三個屬性值
SELECT @x.value('local-name((/Employees/Employee[1]/@*[position()=3])[1])','VARCHAR(20)') AS AttName
/*
AttName
--------------------
QQ
*/
--返回第二個元素的第四個屬性值
SELECT @x.value('local-name((/Employees/Employee[2]/@*[position()=4])[1])','VARCHAR(20)') AS AttName
/*
AttName
--------------------
TEL
*/
--通過變量傳遞位置返回屬性值
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.判斷是XML中否存在相應的屬性
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
*/
--傳遞變量判斷是否存在
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.循環遍歷元素的所有屬性
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')--獲得屬性總數量
-- 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" />
*/
--通過變量獲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.循環遍歷獲得所有子元素
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 中對XML數據的五種基本操作
1.xml.exist
輸入為XQuery表達式，返回0，1或是Null。0表示不存在，1表示存在，Null表示輸入為空
2.xml.value
輸入為XQuery表達式，返回一個SQL Server標量值
3.xml.query
輸入為XQuery表達式，返回一個SQL Server XML類型流
4.xml.nodes
輸入為XQuery表達式，返回一個XML格式文檔的一列行集
5.xml.modify
使用XQuery表達式對XML的節點進行insert , update 和 delete 操作。
下面通過例子對上面的五種操作進行說明：
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)')
結果集為：
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')
結果集分別為：
<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)
結果集分別為：
<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>[email protected]</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) --第三層
) as p
/*
1001 Email [email protected]
1001 Phone 678945546
1001 QQ 36575
1001 Addr 36575
*/
/*
解析XML存儲過程
*/
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>[email protected]</Email>
<Phone>678945546</Phone>
<QQ>36575</QQ>
<Addr>36575</Addr>
</People>
</Peoples>'
EXECUTE sp_ExportXml @x,'/*/*/*'
希望本文所述對大家SQL Server數據庫程序設計有所幫助。
