Xquery实例演示

Xquery实例演示
本文将重点演示两个Xquery实例，以此来说明Xquery的使用:
  1.FLOW的使用
 2.Xquery构造器
本文示例代码均在Eclipse  oXygen插件下通过测试！

1.xml源文件：

xml version="1.0" encoding="gb2312" ?>
xml-stylesheet type="text/xsl" href="users.xsl" ?>

< users  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance"
 xsi:noNamespaceSchemaLocation ="users.xsd" >
   < user  id ="0" >
     < usertype > admin usertype >
     < username > tony username >
     < password > 23456-adm-4578 password >
     < userphone > 13241470658 userphone >
     < email > [email protected] email >
     < introduction > 管理员 introduction >
   user >
   < user  id ="1" >
     < usertype > prof usertype >
     < username > mark king username >
     < password > 11111-sdf-3333 password >
     < userphone > 13423456789 userphone >
     < email > [email protected] email >
     < introduction > 知名的XXXXXX introduction >
   user >
   < user  id ="2" >
    
     < usertype > prof usertype >
     < username > tom username >
     < password > 22223-ffk-3333 password >
     < userphone > 13501234567 userphone >
     < email > [email protected] email >
     < introduction > 国内著名的XXXXX introduction >
   user >
< user  id ="3" >
     < usertype > pro usertype >
     < username > gate username >
     < password > 33334-huj-3456 password >
     < userphone > 13634567890 userphone >
     < email > [email protected] email >
     < introduction > 全球著名的XXXXX introduction >
   user >
  ........(略...)
users >

实例1（XQ1） ：for 与let的比较

< results >

{
    
 for $user in  doc("users.xml")/users/user
 return
    < userInfo >
     { $user/username }
    userInfo >

}
{
 let $userlet := doc("users.xml")/users/user
 return
      < userInfomation >
     { $userlet/username }
     userInfomation >
   }
   
   {
 let $userlet := doc("users.xml")/users/user
 return
      < userInfomation >
       < username >
     { $userlet/username/text()}
      username >
     userInfomation >
   }
results >

-----------------------------------------------------------------
results:

xml version="1.0" encoding="UTF-8" ?>
< results >
   
    < userInfo >
       < username  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" > tony username >
    userInfo >
    < userInfo >
       < username  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" > mark king username >
    userInfo >
    < userInfo >
       < username  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" > tom username >
    userInfo >
    < userInfo >
       < username  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" > gate username >
    userInfo >
 
    < userInfomation >
       < username  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" > tony username >
       < username  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" > mark king username >
       < username  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" > tom username >
       < username  xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" > gate username >
    userInfomation >

    < userInfomation >
       < username > tonymark kingtomgate username >
    userInfomation >
results >

实例2（XQ2）：构造器演示

< results >
{
    
 for $user in  doc("users.xml")/users/user
 let $name:=$user/username,
     $introduction:=$user/introduction,
     $email:=$user/email
 where 
      $user/@id="3"
 return
  element user{
      element a{
      attribute href {"www.google.com/search?q=tony"},
      $name/text()
      },
      element introduction{
       $introduction/text()
      },
      element email{
      /users/user[@id="3"]/email/text() //即$email/text()
      },
       < usertype >
        { /users/user[@id="3"]/usertype/text()}
       usertype >
      
      
      }
      
 }

results >

///

results:

xml version="1.0" encoding="UTF-8" ?>
< results >
    < user >
       < a  href ="www.google.com/search?q=tony" > gate a >
       < introduction > 全球著名的XXXXX introduction >
       < email > [email protected] email >
    user >
results >

总结：1.return子句以xml格式返回.
      2.两种构造方式可以混合使用。