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。
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