为什么Xquery中的计算属性变为null？_Xquery

为什么Xquery中的计算属性变为null？

xquery

为什么Xquery中的计算属性变为null？,xquery,Xquery,我写这段代码是为了根据专辑的年份列出专辑，并给出id和与每个标题相关的属性，但我得到的id是空的 <Production_by_years> { for $i in distinct-values(//Album/Year/text()) return element {"Year"} { element {"year"}{$i}, for $o in //Album/Year[text() eq $i] ret

我写这段代码是为了根据专辑的年份列出专辑，并给出id和与每个标题相关的属性，但我得到的id是空的

<Production_by_years>
{
    for $i in distinct-values(//Album/Year/text())
    return element {"Year"}
    {
        element {"year"}{$i},
        for $o in //Album/Year[text() eq $i]
        return element {"Title"}{attribute {"id"}{//Album/Year[text() eq $i]/../@ALbumID},$o/text()}
    }
}
</Production_by_years>

      <Artist ArtistID="Ar_0000" countryID="US">
        <Name>
            <FirstName>Katey </FirstName>
            <LastName>Berry</LastName>           
        </Name>
         <pic>Dev.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0002" countryID="UK">
        <Name>
            <FirstName>Selena  </FirstName>
            <LastName>Gomez</LastName>

        </Name>

    <pic/></Artist>
    <Artist ArtistID="Ar_0003" countryID="US">
        <Name>
            <FirstName>Avril  </FirstName>
            <LastName>Lavigne</LastName>

        </Name>
      <pic>avrail.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0014" countryID="UK">
        <Name>
            <FirstName>Marlon </FirstName>
            <LastName>Roudette</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0017" countryID="US">
        <Name>
            <FirstName>Julio </FirstName>
            <LastName>Iglesias</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0015" countryID="US">
        <Name>
            <FirstName>Dev </FirstName>
            <LastName>Dev</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0005" countryID="FR">
        <Name>
            <FirstName>Kelly </FirstName>
            <LastName>Clarkson </LastName>


        </Name>

    </Artist>
    <Artist ArtistID="Ar_0006" countryID="FR">
        <Name>
            <FirstName>Charles  </FirstName>
            <LastName> Aznavour</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0007" countryID="ME">
        <Name>
            <FirstName>Serebro </FirstName>
            <LastName>Serebro</LastName>

        </Name>

    </Artist>  
    <Artist ArtistID="Ar_0008" countryID="US">
        <Name>
            <FirstName>Justine </FirstName>
            <LastName>beiber</LastName>

        </Name>


    <pic>b.jpg</pic></Artist> 
    <Artist ArtistID="Ar_0016" countryID="FR">
        <Name>
            <FirstName>Paul</FirstName>
            <LastName>Mauria</LastName>

        </Name>

    </Artist>

    <Artist ArtistID="Ar_0010" countryID="US">

        <Name>
            <FirstName>Elissa </FirstName>
            <LastName>Elissa</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0001" countryID="US">
        <Name>

        <FirstName>farpus </FirstName>
        <LastName>ff</LastName>
        </Name>


    </Artist>   
    <Artist ArtistID="Ar_0009" countryID="FR">
        <Name>
            <FirstName>Mireille </FirstName>
            <LastName>Mathieu</LastName>
        </Name>

        </Artist>

    <Artist ArtistID="Ar_0013" countryID="US">
        <Name>
            <FirstName>Rami</FirstName>
            <LastName>Ayash</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0011" countryID="US">
        <Name>
            <FirstName>Nancy </FirstName>
            <LastName>Ajram</LastName>

        </Name>

    </Artist>  
     <Artist ArtistID="Ar_0012" countryID="US">
        <Name>
            <FirstName>Wafiq </FirstName>
            <LastName>Habib</LastName>

        </Name>

    </Artist> 
    <Album AlbumID="AL_0000" ArtistID="Ar_0000" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>Calfornia Girls</Title>
        <Price>12.00</Price>      
        <Year>2012</Year>
    </Album>  
  <Album AlbumID="AL_0017" ArtistID="Ar_0001" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>CCéline Dion</Title>
        <Price>12.00</Price>      
        <Year>2009</Year>
    </Album>
    <Album AlbumID="AL_0001" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>confessions</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0800" ArtistID="Ar_0000" CompanyID="C_5" GenreName="Pop HipHop R_and_B">
        <Title> Mourir d'aimer</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0801" ArtistID="Ar_0002" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>Diseny girl</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0802" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>also this</Title>
        <Price>13.00</Price>
        <Year>2009</Year>
    </Album><Album AlbumID="AL_0804" ArtistID="Ar_0006" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>now </Title>
        <Price>6</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0806" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>for love</Title>
        <Price>6</Price>
        <Year>2006</Year>
    </Album><Album AlbumID="AL_0807" ArtistID="Ar_0006" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>I can do this</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0002" ArtistID="Ar_0006" CompanyID="C_6" GenreName="Pop HipHop R_and_B">
        <Title>Here adn now</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album>
    <Album AlbumID="AL_0003" ArtistID="Ar_0000" CompanyID="C_4" GenreName=" HipHop R_and_B">
        <Title>Teenge Dream</Title>
        <Price>11.00</Price>
        <Year>2010</Year>
    </Album>  
  <Album AlbumID="AL_0005" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Future of sex</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album><Album AlbumID="AL_1000" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Love Stond</Title>
        <Price>8.00</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_1001" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Baby</Title>
        <Price>8.00</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_1002" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>never say never</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album>
    <Album AlbumID="AL_0450" ArtistID="Ar_0016" CompanyID="C_5" GenreName="HipHop">
        <Title>Toccata</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
  <Album AlbumID="AL_0006" ArtistID="Ar_0001" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2011</Year>
    </Album>
  <Album AlbumID="AL_0032" ArtistID="Ar_0010" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2014</Year>
    </Album>

  <Album AlbumID="AL_0007" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>Love You Like A Love Song</Title>
        <Price>19.00</Price>      
        <Year>2011</Year>
    </Album>
    <Album AlbumID="AL_0008" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Metal">
        <Title>Wish You Were Here</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0009" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>I Like How It Feel</Title>
        <Price>13.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0010" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>J'entends la musique</Title>
        <Price>11.00</Price>
        <Year>2008</Year>
    </Album> 
  <Album AlbumID="AL_0011" ArtistID="Ar_0011" CompanyID="C_2" GenreName="Metal">
        <Title>AL7B KLO</Title>
        <Price>57.00</Price>
        <Year>2007</Year>
    </Album>
  <Album AlbumID="AL_0240" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>LAEK LAKE</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
  </Album><Album AlbumID="AL_0012" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>I like it</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0013" ArtistID="Ar_0013" CompanyID="C_5" GenreName="Electro">
        <Title>I like you</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0234" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Far more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0233" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Now here</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>
    <Album AlbumID="AL_0090" ArtistID="Ar_0002" CompanyID="C_6" GenreName="HipHop Electro">
        <Title>HABEBE</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0100" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">
        <Title>say no more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>

    <Album AlbumID="AL_0345" ArtistID="Ar_0006" CompanyID="C_2" GenreName="HipHop Electro">



        <Title>We Found Love</Title>
        <Price>12.00</Price>
        <Year>2005</Year>
    </Album><Album AlbumID="AL_0015" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">



        <Title>love is here</Title>
        <Price>6</Price>
        <Year>2005</Year>
    </Album>

  <Album AlbumID="AL_0016" ArtistID="Ar_0010" CompanyID="C_1" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2011</Year>
  </Album><Album AlbumID="AL_0066" ArtistID="Ar_0003" CompanyID="C_2" GenreName="Metal">



        <Title>take care</Title>
        <Price>5</Price>
        <Year>2005</Year>
  </Album><Album AlbumID="AL_0067" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>bad girl</Title>
        <Price>5</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_0076" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>it's me</Title>
        <Price>5</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_0056" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>I can say</Title>
        <Price>5</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0055" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>when that</Title>
        <Price>5</Price>
        <Year>201</Year>
    </Album><Album AlbumID="AL_0043" ArtistID="Ar_0003" CompanyID="C_8" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2013</Year>
    </Album><Album AlbumID="AL_0039" ArtistID="Ar_0005" CompanyID="C_7" GenreName=" HipHop R_and_B">



        <Title>shit happens</Title>
        <Price>4</Price>
        <Year>2011</Year>
    </Album>

    <Genre GenreName="Rap"/>
    <Genre GenreName="Country"/>
    <Genre GenreName="R_and_B"/>
    <Genre GenreName="HipHop"/>
    <Genre GenreName="House"/>
    <Genre GenreName="Pop"/>
    <Genre GenreName="Electro"/>
    <Genre GenreName="Blues"/>
    <Genre GenreName="Punck"/>
    <Genre GenreName="Rock"/>
    <Genre GenreName="Metal"/>
    <Genre GenreName="Alternative_Rock"/>

  <Company CompanyID="C_1">
   CBS Records
  </Company>
  <Company CompanyID="C_2">
  RCA
  </Company>
  <Company CompanyID="C_3">
    WEA   
  </Company>
  <Company CompanyID="C_4">
  Cloumbia
  </Company>
  <Company CompanyID="C_5">
   Virgin Records 
  </Company>
  <Company CompanyID="C_6">   
  Pickwick
  </Company>
  <Company CompanyID="C_7">
   Atlantic
  </Company>
  <Company CompanyID="C_8">
   Mega
  </Company>
  <Company CompanyID="C_9">
   Grammy
  </Company>
  <Company CompanyID="C_10">
   Wordo
  </Company>
  <Company CompanyID="C_11">
    Fox
  </Company>


  <Country countryID="US">
    United State  
  </Country>
  <Country countryID="UK">
    United Kingdom
  </Country>
  <Country countryID="FR">
    France
  </Country>
  <Country countryID="GR">
    Germany
  </Country>
  <Country countryID="ME">
    Mexico
  </Country>
  <Country countryID="SP">
    Spain
  </Country>
  <Country countryID="JP">
    Japneas
  </Country>

</MusicCatalog>


{
以不同的值（//Album/Year/text（）表示$i）
返回元素{“年”}
{
元素{“年”}{$i}，
对于//Album/年中的$o[text（）eq$i]
返回元素{“Title”}{attribute{“id”}{//Album/Year[text（）eq$i]/../@ALbumID}，$o/text（）}
}
}

这是xml文件

      <Artist ArtistID="Ar_0000" countryID="US">
        <Name>
            <FirstName>Katey </FirstName>
            <LastName>Berry</LastName>           
        </Name>
         <pic>Dev.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0002" countryID="UK">
        <Name>
            <FirstName>Selena  </FirstName>
            <LastName>Gomez</LastName>

        </Name>

    <pic/></Artist>
    <Artist ArtistID="Ar_0003" countryID="US">
        <Name>
            <FirstName>Avril  </FirstName>
            <LastName>Lavigne</LastName>

        </Name>
      <pic>avrail.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0014" countryID="UK">
        <Name>
            <FirstName>Marlon </FirstName>
            <LastName>Roudette</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0017" countryID="US">
        <Name>
            <FirstName>Julio </FirstName>
            <LastName>Iglesias</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0015" countryID="US">
        <Name>
            <FirstName>Dev </FirstName>
            <LastName>Dev</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0005" countryID="FR">
        <Name>
            <FirstName>Kelly </FirstName>
            <LastName>Clarkson </LastName>


        </Name>

    </Artist>
    <Artist ArtistID="Ar_0006" countryID="FR">
        <Name>
            <FirstName>Charles  </FirstName>
            <LastName> Aznavour</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0007" countryID="ME">
        <Name>
            <FirstName>Serebro </FirstName>
            <LastName>Serebro</LastName>

        </Name>

    </Artist>  
    <Artist ArtistID="Ar_0008" countryID="US">
        <Name>
            <FirstName>Justine </FirstName>
            <LastName>beiber</LastName>

        </Name>


    <pic>b.jpg</pic></Artist> 
    <Artist ArtistID="Ar_0016" countryID="FR">
        <Name>
            <FirstName>Paul</FirstName>
            <LastName>Mauria</LastName>

        </Name>

    </Artist>

    <Artist ArtistID="Ar_0010" countryID="US">

        <Name>
            <FirstName>Elissa </FirstName>
            <LastName>Elissa</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0001" countryID="US">
        <Name>

        <FirstName>farpus </FirstName>
        <LastName>ff</LastName>
        </Name>


    </Artist>   
    <Artist ArtistID="Ar_0009" countryID="FR">
        <Name>
            <FirstName>Mireille </FirstName>
            <LastName>Mathieu</LastName>
        </Name>

        </Artist>

    <Artist ArtistID="Ar_0013" countryID="US">
        <Name>
            <FirstName>Rami</FirstName>
            <LastName>Ayash</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0011" countryID="US">
        <Name>
            <FirstName>Nancy </FirstName>
            <LastName>Ajram</LastName>

        </Name>

    </Artist>  
     <Artist ArtistID="Ar_0012" countryID="US">
        <Name>
            <FirstName>Wafiq </FirstName>
            <LastName>Habib</LastName>

        </Name>

    </Artist> 
    <Album AlbumID="AL_0000" ArtistID="Ar_0000" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>Calfornia Girls</Title>
        <Price>12.00</Price>      
        <Year>2012</Year>
    </Album>  
  <Album AlbumID="AL_0017" ArtistID="Ar_0001" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>CCéline Dion</Title>
        <Price>12.00</Price>      
        <Year>2009</Year>
    </Album>
    <Album AlbumID="AL_0001" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>confessions</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0800" ArtistID="Ar_0000" CompanyID="C_5" GenreName="Pop HipHop R_and_B">
        <Title> Mourir d'aimer</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0801" ArtistID="Ar_0002" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>Diseny girl</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0802" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>also this</Title>
        <Price>13.00</Price>
        <Year>2009</Year>
    </Album><Album AlbumID="AL_0804" ArtistID="Ar_0006" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>now </Title>
        <Price>6</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0806" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>for love</Title>
        <Price>6</Price>
        <Year>2006</Year>
    </Album><Album AlbumID="AL_0807" ArtistID="Ar_0006" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>I can do this</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0002" ArtistID="Ar_0006" CompanyID="C_6" GenreName="Pop HipHop R_and_B">
        <Title>Here adn now</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album>
    <Album AlbumID="AL_0003" ArtistID="Ar_0000" CompanyID="C_4" GenreName=" HipHop R_and_B">
        <Title>Teenge Dream</Title>
        <Price>11.00</Price>
        <Year>2010</Year>
    </Album>  
  <Album AlbumID="AL_0005" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Future of sex</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album><Album AlbumID="AL_1000" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Love Stond</Title>
        <Price>8.00</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_1001" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Baby</Title>
        <Price>8.00</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_1002" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>never say never</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album>
    <Album AlbumID="AL_0450" ArtistID="Ar_0016" CompanyID="C_5" GenreName="HipHop">
        <Title>Toccata</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
  <Album AlbumID="AL_0006" ArtistID="Ar_0001" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2011</Year>
    </Album>
  <Album AlbumID="AL_0032" ArtistID="Ar_0010" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2014</Year>
    </Album>

  <Album AlbumID="AL_0007" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>Love You Like A Love Song</Title>
        <Price>19.00</Price>      
        <Year>2011</Year>
    </Album>
    <Album AlbumID="AL_0008" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Metal">
        <Title>Wish You Were Here</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0009" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>I Like How It Feel</Title>
        <Price>13.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0010" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>J'entends la musique</Title>
        <Price>11.00</Price>
        <Year>2008</Year>
    </Album> 
  <Album AlbumID="AL_0011" ArtistID="Ar_0011" CompanyID="C_2" GenreName="Metal">
        <Title>AL7B KLO</Title>
        <Price>57.00</Price>
        <Year>2007</Year>
    </Album>
  <Album AlbumID="AL_0240" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>LAEK LAKE</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
  </Album><Album AlbumID="AL_0012" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>I like it</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0013" ArtistID="Ar_0013" CompanyID="C_5" GenreName="Electro">
        <Title>I like you</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0234" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Far more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0233" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Now here</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>
    <Album AlbumID="AL_0090" ArtistID="Ar_0002" CompanyID="C_6" GenreName="HipHop Electro">
        <Title>HABEBE</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0100" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">
        <Title>say no more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>

    <Album AlbumID="AL_0345" ArtistID="Ar_0006" CompanyID="C_2" GenreName="HipHop Electro">



        <Title>We Found Love</Title>
        <Price>12.00</Price>
        <Year>2005</Year>
    </Album><Album AlbumID="AL_0015" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">



        <Title>love is here</Title>
        <Price>6</Price>
        <Year>2005</Year>
    </Album>

  <Album AlbumID="AL_0016" ArtistID="Ar_0010" CompanyID="C_1" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2011</Year>
  </Album><Album AlbumID="AL_0066" ArtistID="Ar_0003" CompanyID="C_2" GenreName="Metal">



        <Title>take care</Title>
        <Price>5</Price>
        <Year>2005</Year>
  </Album><Album AlbumID="AL_0067" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>bad girl</Title>
        <Price>5</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_0076" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>it's me</Title>
        <Price>5</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_0056" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>I can say</Title>
        <Price>5</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0055" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>when that</Title>
        <Price>5</Price>
        <Year>201</Year>
    </Album><Album AlbumID="AL_0043" ArtistID="Ar_0003" CompanyID="C_8" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2013</Year>
    </Album><Album AlbumID="AL_0039" ArtistID="Ar_0005" CompanyID="C_7" GenreName=" HipHop R_and_B">



        <Title>shit happens</Title>
        <Price>4</Price>
        <Year>2011</Year>
    </Album>

    <Genre GenreName="Rap"/>
    <Genre GenreName="Country"/>
    <Genre GenreName="R_and_B"/>
    <Genre GenreName="HipHop"/>
    <Genre GenreName="House"/>
    <Genre GenreName="Pop"/>
    <Genre GenreName="Electro"/>
    <Genre GenreName="Blues"/>
    <Genre GenreName="Punck"/>
    <Genre GenreName="Rock"/>
    <Genre GenreName="Metal"/>
    <Genre GenreName="Alternative_Rock"/>

  <Company CompanyID="C_1">
   CBS Records
  </Company>
  <Company CompanyID="C_2">
  RCA
  </Company>
  <Company CompanyID="C_3">
    WEA   
  </Company>
  <Company CompanyID="C_4">
  Cloumbia
  </Company>
  <Company CompanyID="C_5">
   Virgin Records 
  </Company>
  <Company CompanyID="C_6">   
  Pickwick
  </Company>
  <Company CompanyID="C_7">
   Atlantic
  </Company>
  <Company CompanyID="C_8">
   Mega
  </Company>
  <Company CompanyID="C_9">
   Grammy
  </Company>
  <Company CompanyID="C_10">
   Wordo
  </Company>
  <Company CompanyID="C_11">
    Fox
  </Company>


  <Country countryID="US">
    United State  
  </Country>
  <Country countryID="UK">
    United Kingdom
  </Country>
  <Country countryID="FR">
    France
  </Country>
  <Country countryID="GR">
    Germany
  </Country>
  <Country countryID="ME">
    Mexico
  </Country>
  <Country countryID="SP">
    Spain
  </Country>
  <Country countryID="JP">
    Japneas
  </Country>

</MusicCatalog>


凯蒂
浆果
Dev.JPG
赛琳娜
戈麦斯
艾薇儿
拉维尼
avrail.JPG
马龙
卢代特
胡里奥
伊格莱西亚斯
发展
发展
凯莉
克拉克森
查尔斯
阿兹纳沃
塞雷布罗
塞雷布罗
贾斯汀
贝伯
b、 jpg
保罗
茉莉亚
伊丽莎
伊丽莎
法布斯
ff
米雷尔
马修
拉米
阿亚什
南希
阿杰拉姆
瓦菲克
哈比卜
卡尔弗尼亚女孩
12
2012
迪翁
12
2009
自白
9
2008
穆里尔·德艾默
13
2014
病态女孩
13
2014
还有这个
13
2009
现在
6.
2010
为了爱
6.
2006
我能做到
13
2014
现在在这里
13
2014
丁格梦
11
2010
性的未来
8
2007
爱情石
8
2011
宝贝
8
2012
永不言败
8
2007
托卡塔
12
2013
阴凉处
12
2011
阴凉处
12
2014
爱你就像一首情歌
19
2011
希望你在这里
9
2008
我喜欢它的感觉
13
2013
音乐之旅
11
2008
AL7B KLO
57
2007
莱克湖
12
2013
我喜欢它
12
2013
我喜欢你
12
2010
远不止
12
2010
现在在这里
12
2010
哈比
12
2010
别再说了
12
2010
我们找到了爱
12
2005
爱就在这里
6.
2005
顶端
5.
2011
当心
5.
2005
坏女孩
5.
2011
是我
5.
2012
我可以说
5.
2010
什么时候
5.
201
顶端
5.
2013
大便发生了
4.
2011
哥伦比亚唱片公司
RCA
威阿
克隆瘤
维珍唱片
匹克威克
大西洋
巨大的
格莱美
沃多
福克斯
美国
大不列颠联合王国
法国
德国
墨西哥
西班牙
日本

您有一个输入错误：@ALbumID->@ALbumID，但我建议更改您的内部循环以将album用作上下文：

      <Artist ArtistID="Ar_0000" countryID="US">
        <Name>
            <FirstName>Katey </FirstName>
            <LastName>Berry</LastName>           
        </Name>
         <pic>Dev.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0002" countryID="UK">
        <Name>
            <FirstName>Selena  </FirstName>
            <LastName>Gomez</LastName>

        </Name>

    <pic/></Artist>
    <Artist ArtistID="Ar_0003" countryID="US">
        <Name>
            <FirstName>Avril  </FirstName>
            <LastName>Lavigne</LastName>

        </Name>
      <pic>avrail.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0014" countryID="UK">
        <Name>
            <FirstName>Marlon </FirstName>
            <LastName>Roudette</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0017" countryID="US">
        <Name>
            <FirstName>Julio </FirstName>
            <LastName>Iglesias</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0015" countryID="US">
        <Name>
            <FirstName>Dev </FirstName>
            <LastName>Dev</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0005" countryID="FR">
        <Name>
            <FirstName>Kelly </FirstName>
            <LastName>Clarkson </LastName>


        </Name>

    </Artist>
    <Artist ArtistID="Ar_0006" countryID="FR">
        <Name>
            <FirstName>Charles  </FirstName>
            <LastName> Aznavour</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0007" countryID="ME">
        <Name>
            <FirstName>Serebro </FirstName>
            <LastName>Serebro</LastName>

        </Name>

    </Artist>  
    <Artist ArtistID="Ar_0008" countryID="US">
        <Name>
            <FirstName>Justine </FirstName>
            <LastName>beiber</LastName>

        </Name>


    <pic>b.jpg</pic></Artist> 
    <Artist ArtistID="Ar_0016" countryID="FR">
        <Name>
            <FirstName>Paul</FirstName>
            <LastName>Mauria</LastName>

        </Name>

    </Artist>

    <Artist ArtistID="Ar_0010" countryID="US">

        <Name>
            <FirstName>Elissa </FirstName>
            <LastName>Elissa</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0001" countryID="US">
        <Name>

        <FirstName>farpus </FirstName>
        <LastName>ff</LastName>
        </Name>


    </Artist>   
    <Artist ArtistID="Ar_0009" countryID="FR">
        <Name>
            <FirstName>Mireille </FirstName>
            <LastName>Mathieu</LastName>
        </Name>

        </Artist>

    <Artist ArtistID="Ar_0013" countryID="US">
        <Name>
            <FirstName>Rami</FirstName>
            <LastName>Ayash</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0011" countryID="US">
        <Name>
            <FirstName>Nancy </FirstName>
            <LastName>Ajram</LastName>

        </Name>

    </Artist>  
     <Artist ArtistID="Ar_0012" countryID="US">
        <Name>
            <FirstName>Wafiq </FirstName>
            <LastName>Habib</LastName>

        </Name>

    </Artist> 
    <Album AlbumID="AL_0000" ArtistID="Ar_0000" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>Calfornia Girls</Title>
        <Price>12.00</Price>      
        <Year>2012</Year>
    </Album>  
  <Album AlbumID="AL_0017" ArtistID="Ar_0001" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>CCéline Dion</Title>
        <Price>12.00</Price>      
        <Year>2009</Year>
    </Album>
    <Album AlbumID="AL_0001" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>confessions</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0800" ArtistID="Ar_0000" CompanyID="C_5" GenreName="Pop HipHop R_and_B">
        <Title> Mourir d'aimer</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0801" ArtistID="Ar_0002" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>Diseny girl</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0802" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>also this</Title>
        <Price>13.00</Price>
        <Year>2009</Year>
    </Album><Album AlbumID="AL_0804" ArtistID="Ar_0006" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>now </Title>
        <Price>6</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0806" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>for love</Title>
        <Price>6</Price>
        <Year>2006</Year>
    </Album><Album AlbumID="AL_0807" ArtistID="Ar_0006" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>I can do this</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0002" ArtistID="Ar_0006" CompanyID="C_6" GenreName="Pop HipHop R_and_B">
        <Title>Here adn now</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album>
    <Album AlbumID="AL_0003" ArtistID="Ar_0000" CompanyID="C_4" GenreName=" HipHop R_and_B">
        <Title>Teenge Dream</Title>
        <Price>11.00</Price>
        <Year>2010</Year>
    </Album>  
  <Album AlbumID="AL_0005" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Future of sex</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album><Album AlbumID="AL_1000" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Love Stond</Title>
        <Price>8.00</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_1001" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Baby</Title>
        <Price>8.00</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_1002" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>never say never</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album>
    <Album AlbumID="AL_0450" ArtistID="Ar_0016" CompanyID="C_5" GenreName="HipHop">
        <Title>Toccata</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
  <Album AlbumID="AL_0006" ArtistID="Ar_0001" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2011</Year>
    </Album>
  <Album AlbumID="AL_0032" ArtistID="Ar_0010" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2014</Year>
    </Album>

  <Album AlbumID="AL_0007" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>Love You Like A Love Song</Title>
        <Price>19.00</Price>      
        <Year>2011</Year>
    </Album>
    <Album AlbumID="AL_0008" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Metal">
        <Title>Wish You Were Here</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0009" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>I Like How It Feel</Title>
        <Price>13.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0010" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>J'entends la musique</Title>
        <Price>11.00</Price>
        <Year>2008</Year>
    </Album> 
  <Album AlbumID="AL_0011" ArtistID="Ar_0011" CompanyID="C_2" GenreName="Metal">
        <Title>AL7B KLO</Title>
        <Price>57.00</Price>
        <Year>2007</Year>
    </Album>
  <Album AlbumID="AL_0240" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>LAEK LAKE</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
  </Album><Album AlbumID="AL_0012" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>I like it</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0013" ArtistID="Ar_0013" CompanyID="C_5" GenreName="Electro">
        <Title>I like you</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0234" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Far more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0233" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Now here</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>
    <Album AlbumID="AL_0090" ArtistID="Ar_0002" CompanyID="C_6" GenreName="HipHop Electro">
        <Title>HABEBE</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0100" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">
        <Title>say no more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>

    <Album AlbumID="AL_0345" ArtistID="Ar_0006" CompanyID="C_2" GenreName="HipHop Electro">



        <Title>We Found Love</Title>
        <Price>12.00</Price>
        <Year>2005</Year>
    </Album><Album AlbumID="AL_0015" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">



        <Title>love is here</Title>
        <Price>6</Price>
        <Year>2005</Year>
    </Album>

  <Album AlbumID="AL_0016" ArtistID="Ar_0010" CompanyID="C_1" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2011</Year>
  </Album><Album AlbumID="AL_0066" ArtistID="Ar_0003" CompanyID="C_2" GenreName="Metal">



        <Title>take care</Title>
        <Price>5</Price>
        <Year>2005</Year>
  </Album><Album AlbumID="AL_0067" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>bad girl</Title>
        <Price>5</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_0076" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>it's me</Title>
        <Price>5</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_0056" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>I can say</Title>
        <Price>5</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0055" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>when that</Title>
        <Price>5</Price>
        <Year>201</Year>
    </Album><Album AlbumID="AL_0043" ArtistID="Ar_0003" CompanyID="C_8" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2013</Year>
    </Album><Album AlbumID="AL_0039" ArtistID="Ar_0005" CompanyID="C_7" GenreName=" HipHop R_and_B">



        <Title>shit happens</Title>
        <Price>4</Price>
        <Year>2011</Year>
    </Album>

    <Genre GenreName="Rap"/>
    <Genre GenreName="Country"/>
    <Genre GenreName="R_and_B"/>
    <Genre GenreName="HipHop"/>
    <Genre GenreName="House"/>
    <Genre GenreName="Pop"/>
    <Genre GenreName="Electro"/>
    <Genre GenreName="Blues"/>
    <Genre GenreName="Punck"/>
    <Genre GenreName="Rock"/>
    <Genre GenreName="Metal"/>
    <Genre GenreName="Alternative_Rock"/>

  <Company CompanyID="C_1">
   CBS Records
  </Company>
  <Company CompanyID="C_2">
  RCA
  </Company>
  <Company CompanyID="C_3">
    WEA   
  </Company>
  <Company CompanyID="C_4">
  Cloumbia
  </Company>
  <Company CompanyID="C_5">
   Virgin Records 
  </Company>
  <Company CompanyID="C_6">   
  Pickwick
  </Company>
  <Company CompanyID="C_7">
   Atlantic
  </Company>
  <Company CompanyID="C_8">
   Mega
  </Company>
  <Company CompanyID="C_9">
   Grammy
  </Company>
  <Company CompanyID="C_10">
   Wordo
  </Company>
  <Company CompanyID="C_11">
    Fox
  </Company>


  <Country countryID="US">
    United State  
  </Country>
  <Country countryID="UK">
    United Kingdom
  </Country>
  <Country countryID="FR">
    France
  </Country>
  <Country countryID="GR">
    Germany
  </Country>
  <Country countryID="ME">
    Mexico
  </Country>
  <Country countryID="SP">
    Spain
  </Country>
  <Country countryID="JP">
    Japneas
  </Country>

</MusicCatalog>

for $album in //Album[Year = $i]
return (: something :)

选择器区分大小写，但即使您修复了输入错误：

@ALbumID

@ALbumID

，您仍在使用

/Album/Year[…]迭代年
，而不是年
。因此，当您选择@AlbumID
时，它将实际匹配该年的所有@AlbumID
，并返回所有这些值的空格分隔字符串
      <Artist ArtistID="Ar_0000" countryID="US">
        <Name>
            <FirstName>Katey </FirstName>
            <LastName>Berry</LastName>           
        </Name>
         <pic>Dev.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0002" countryID="UK">
        <Name>
            <FirstName>Selena  </FirstName>
            <LastName>Gomez</LastName>

        </Name>

    <pic/></Artist>
    <Artist ArtistID="Ar_0003" countryID="US">
        <Name>
            <FirstName>Avril  </FirstName>
            <LastName>Lavigne</LastName>

        </Name>
      <pic>avrail.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0014" countryID="UK">
        <Name>
            <FirstName>Marlon </FirstName>
            <LastName>Roudette</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0017" countryID="US">
        <Name>
            <FirstName>Julio </FirstName>
            <LastName>Iglesias</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0015" countryID="US">
        <Name>
            <FirstName>Dev </FirstName>
            <LastName>Dev</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0005" countryID="FR">
        <Name>
            <FirstName>Kelly </FirstName>
            <LastName>Clarkson </LastName>


        </Name>

    </Artist>
    <Artist ArtistID="Ar_0006" countryID="FR">
        <Name>
            <FirstName>Charles  </FirstName>
            <LastName> Aznavour</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0007" countryID="ME">
        <Name>
            <FirstName>Serebro </FirstName>
            <LastName>Serebro</LastName>

        </Name>

    </Artist>  
    <Artist ArtistID="Ar_0008" countryID="US">
        <Name>
            <FirstName>Justine </FirstName>
            <LastName>beiber</LastName>

        </Name>


    <pic>b.jpg</pic></Artist> 
    <Artist ArtistID="Ar_0016" countryID="FR">
        <Name>
            <FirstName>Paul</FirstName>
            <LastName>Mauria</LastName>

        </Name>

    </Artist>

    <Artist ArtistID="Ar_0010" countryID="US">

        <Name>
            <FirstName>Elissa </FirstName>
            <LastName>Elissa</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0001" countryID="US">
        <Name>

        <FirstName>farpus </FirstName>
        <LastName>ff</LastName>
        </Name>


    </Artist>   
    <Artist ArtistID="Ar_0009" countryID="FR">
        <Name>
            <FirstName>Mireille </FirstName>
            <LastName>Mathieu</LastName>
        </Name>

        </Artist>

    <Artist ArtistID="Ar_0013" countryID="US">
        <Name>
            <FirstName>Rami</FirstName>
            <LastName>Ayash</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0011" countryID="US">
        <Name>
            <FirstName>Nancy </FirstName>
            <LastName>Ajram</LastName>

        </Name>

    </Artist>  
     <Artist ArtistID="Ar_0012" countryID="US">
        <Name>
            <FirstName>Wafiq </FirstName>
            <LastName>Habib</LastName>

        </Name>

    </Artist> 
    <Album AlbumID="AL_0000" ArtistID="Ar_0000" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>Calfornia Girls</Title>
        <Price>12.00</Price>      
        <Year>2012</Year>
    </Album>  
  <Album AlbumID="AL_0017" ArtistID="Ar_0001" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>CCéline Dion</Title>
        <Price>12.00</Price>      
        <Year>2009</Year>
    </Album>
    <Album AlbumID="AL_0001" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>confessions</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0800" ArtistID="Ar_0000" CompanyID="C_5" GenreName="Pop HipHop R_and_B">
        <Title> Mourir d'aimer</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0801" ArtistID="Ar_0002" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>Diseny girl</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0802" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>also this</Title>
        <Price>13.00</Price>
        <Year>2009</Year>
    </Album><Album AlbumID="AL_0804" ArtistID="Ar_0006" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>now </Title>
        <Price>6</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0806" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>for love</Title>
        <Price>6</Price>
        <Year>2006</Year>
    </Album><Album AlbumID="AL_0807" ArtistID="Ar_0006" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>I can do this</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0002" ArtistID="Ar_0006" CompanyID="C_6" GenreName="Pop HipHop R_and_B">
        <Title>Here adn now</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album>
    <Album AlbumID="AL_0003" ArtistID="Ar_0000" CompanyID="C_4" GenreName=" HipHop R_and_B">
        <Title>Teenge Dream</Title>
        <Price>11.00</Price>
        <Year>2010</Year>
    </Album>  
  <Album AlbumID="AL_0005" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Future of sex</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album><Album AlbumID="AL_1000" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Love Stond</Title>
        <Price>8.00</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_1001" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Baby</Title>
        <Price>8.00</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_1002" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>never say never</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album>
    <Album AlbumID="AL_0450" ArtistID="Ar_0016" CompanyID="C_5" GenreName="HipHop">
        <Title>Toccata</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
  <Album AlbumID="AL_0006" ArtistID="Ar_0001" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2011</Year>
    </Album>
  <Album AlbumID="AL_0032" ArtistID="Ar_0010" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2014</Year>
    </Album>

  <Album AlbumID="AL_0007" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>Love You Like A Love Song</Title>
        <Price>19.00</Price>      
        <Year>2011</Year>
    </Album>
    <Album AlbumID="AL_0008" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Metal">
        <Title>Wish You Were Here</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0009" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>I Like How It Feel</Title>
        <Price>13.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0010" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>J'entends la musique</Title>
        <Price>11.00</Price>
        <Year>2008</Year>
    </Album> 
  <Album AlbumID="AL_0011" ArtistID="Ar_0011" CompanyID="C_2" GenreName="Metal">
        <Title>AL7B KLO</Title>
        <Price>57.00</Price>
        <Year>2007</Year>
    </Album>
  <Album AlbumID="AL_0240" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>LAEK LAKE</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
  </Album><Album AlbumID="AL_0012" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>I like it</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0013" ArtistID="Ar_0013" CompanyID="C_5" GenreName="Electro">
        <Title>I like you</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0234" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Far more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0233" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Now here</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>
    <Album AlbumID="AL_0090" ArtistID="Ar_0002" CompanyID="C_6" GenreName="HipHop Electro">
        <Title>HABEBE</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0100" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">
        <Title>say no more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>

    <Album AlbumID="AL_0345" ArtistID="Ar_0006" CompanyID="C_2" GenreName="HipHop Electro">



        <Title>We Found Love</Title>
        <Price>12.00</Price>
        <Year>2005</Year>
    </Album><Album AlbumID="AL_0015" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">



        <Title>love is here</Title>
        <Price>6</Price>
        <Year>2005</Year>
    </Album>

  <Album AlbumID="AL_0016" ArtistID="Ar_0010" CompanyID="C_1" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2011</Year>
  </Album><Album AlbumID="AL_0066" ArtistID="Ar_0003" CompanyID="C_2" GenreName="Metal">



        <Title>take care</Title>
        <Price>5</Price>
        <Year>2005</Year>
  </Album><Album AlbumID="AL_0067" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>bad girl</Title>
        <Price>5</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_0076" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>it's me</Title>
        <Price>5</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_0056" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>I can say</Title>
        <Price>5</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0055" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>when that</Title>
        <Price>5</Price>
        <Year>201</Year>
    </Album><Album AlbumID="AL_0043" ArtistID="Ar_0003" CompanyID="C_8" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2013</Year>
    </Album><Album AlbumID="AL_0039" ArtistID="Ar_0005" CompanyID="C_7" GenreName=" HipHop R_and_B">



        <Title>shit happens</Title>
        <Price>4</Price>
        <Year>2011</Year>
    </Album>

    <Genre GenreName="Rap"/>
    <Genre GenreName="Country"/>
    <Genre GenreName="R_and_B"/>
    <Genre GenreName="HipHop"/>
    <Genre GenreName="House"/>
    <Genre GenreName="Pop"/>
    <Genre GenreName="Electro"/>
    <Genre GenreName="Blues"/>
    <Genre GenreName="Punck"/>
    <Genre GenreName="Rock"/>
    <Genre GenreName="Metal"/>
    <Genre GenreName="Alternative_Rock"/>

  <Company CompanyID="C_1">
   CBS Records
  </Company>
  <Company CompanyID="C_2">
  RCA
  </Company>
  <Company CompanyID="C_3">
    WEA   
  </Company>
  <Company CompanyID="C_4">
  Cloumbia
  </Company>
  <Company CompanyID="C_5">
   Virgin Records 
  </Company>
  <Company CompanyID="C_6">   
  Pickwick
  </Company>
  <Company CompanyID="C_7">
   Atlantic
  </Company>
  <Company CompanyID="C_8">
   Mega
  </Company>
  <Company CompanyID="C_9">
   Grammy
  </Company>
  <Company CompanyID="C_10">
   Wordo
  </Company>
  <Company CompanyID="C_11">
    Fox
  </Company>


  <Country countryID="US">
    United State  
  </Country>
  <Country countryID="UK">
    United Kingdom
  </Country>
  <Country countryID="FR">
    France
  </Country>
  <Country countryID="GR">
    Germany
  </Country>
  <Country countryID="ME">
    Mexico
  </Country>
  <Country countryID="SP">
    Spain
  </Country>
  <Country countryID="JP">
    Japneas
  </Country>

</MusicCatalog>

但听起来你只是想按年份对专辑进行分组。这应该是一个良好的开端：
      <Artist ArtistID="Ar_0000" countryID="US">
        <Name>
            <FirstName>Katey </FirstName>
            <LastName>Berry</LastName>           
        </Name>
         <pic>Dev.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0002" countryID="UK">
        <Name>
            <FirstName>Selena  </FirstName>
            <LastName>Gomez</LastName>

        </Name>

    <pic/></Artist>
    <Artist ArtistID="Ar_0003" countryID="US">
        <Name>
            <FirstName>Avril  </FirstName>
            <LastName>Lavigne</LastName>

        </Name>
      <pic>avrail.JPG</pic>
    </Artist>
    <Artist ArtistID="Ar_0014" countryID="UK">
        <Name>
            <FirstName>Marlon </FirstName>
            <LastName>Roudette</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0017" countryID="US">
        <Name>
            <FirstName>Julio </FirstName>
            <LastName>Iglesias</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0015" countryID="US">
        <Name>
            <FirstName>Dev </FirstName>
            <LastName>Dev</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0005" countryID="FR">
        <Name>
            <FirstName>Kelly </FirstName>
            <LastName>Clarkson </LastName>


        </Name>

    </Artist>
    <Artist ArtistID="Ar_0006" countryID="FR">
        <Name>
            <FirstName>Charles  </FirstName>
            <LastName> Aznavour</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0007" countryID="ME">
        <Name>
            <FirstName>Serebro </FirstName>
            <LastName>Serebro</LastName>

        </Name>

    </Artist>  
    <Artist ArtistID="Ar_0008" countryID="US">
        <Name>
            <FirstName>Justine </FirstName>
            <LastName>beiber</LastName>

        </Name>


    <pic>b.jpg</pic></Artist> 
    <Artist ArtistID="Ar_0016" countryID="FR">
        <Name>
            <FirstName>Paul</FirstName>
            <LastName>Mauria</LastName>

        </Name>

    </Artist>

    <Artist ArtistID="Ar_0010" countryID="US">

        <Name>
            <FirstName>Elissa </FirstName>
            <LastName>Elissa</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0001" countryID="US">
        <Name>

        <FirstName>farpus </FirstName>
        <LastName>ff</LastName>
        </Name>


    </Artist>   
    <Artist ArtistID="Ar_0009" countryID="FR">
        <Name>
            <FirstName>Mireille </FirstName>
            <LastName>Mathieu</LastName>
        </Name>

        </Artist>

    <Artist ArtistID="Ar_0013" countryID="US">
        <Name>
            <FirstName>Rami</FirstName>
            <LastName>Ayash</LastName>

        </Name>

    </Artist>
    <Artist ArtistID="Ar_0011" countryID="US">
        <Name>
            <FirstName>Nancy </FirstName>
            <LastName>Ajram</LastName>

        </Name>

    </Artist>  
     <Artist ArtistID="Ar_0012" countryID="US">
        <Name>
            <FirstName>Wafiq </FirstName>
            <LastName>Habib</LastName>

        </Name>

    </Artist> 
    <Album AlbumID="AL_0000" ArtistID="Ar_0000" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>Calfornia Girls</Title>
        <Price>12.00</Price>      
        <Year>2012</Year>
    </Album>  
  <Album AlbumID="AL_0017" ArtistID="Ar_0001" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>CCéline Dion</Title>
        <Price>12.00</Price>      
        <Year>2009</Year>
    </Album>
    <Album AlbumID="AL_0001" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>confessions</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0800" ArtistID="Ar_0000" CompanyID="C_5" GenreName="Pop HipHop R_and_B">
        <Title> Mourir d'aimer</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0801" ArtistID="Ar_0002" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>Diseny girl</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0802" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>also this</Title>
        <Price>13.00</Price>
        <Year>2009</Year>
    </Album><Album AlbumID="AL_0804" ArtistID="Ar_0006" CompanyID="C_8" GenreName="Pop HipHop R_and_B">
        <Title>now </Title>
        <Price>6</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0806" ArtistID="Ar_0006" CompanyID="C_3" GenreName="Pop HipHop R_and_B">
        <Title>for love</Title>
        <Price>6</Price>
        <Year>2006</Year>
    </Album><Album AlbumID="AL_0807" ArtistID="Ar_0006" CompanyID="C_1" GenreName="Pop HipHop R_and_B">
        <Title>I can do this</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album><Album AlbumID="AL_0002" ArtistID="Ar_0006" CompanyID="C_6" GenreName="Pop HipHop R_and_B">
        <Title>Here adn now</Title>
        <Price>13.00</Price>
        <Year>2014</Year>
    </Album>
    <Album AlbumID="AL_0003" ArtistID="Ar_0000" CompanyID="C_4" GenreName=" HipHop R_and_B">
        <Title>Teenge Dream</Title>
        <Price>11.00</Price>
        <Year>2010</Year>
    </Album>  
  <Album AlbumID="AL_0005" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Future of sex</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album><Album AlbumID="AL_1000" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Love Stond</Title>
        <Price>8.00</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_1001" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>Baby</Title>
        <Price>8.00</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_1002" ArtistID="Ar_0008" CompanyID="C_4" GenreName="HipHop">
        <Title>never say never</Title>
        <Price>8.00</Price>
        <Year>2007</Year>
    </Album>
    <Album AlbumID="AL_0450" ArtistID="Ar_0016" CompanyID="C_5" GenreName="HipHop">
        <Title>Toccata</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
  <Album AlbumID="AL_0006" ArtistID="Ar_0001" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2011</Year>
    </Album>
  <Album AlbumID="AL_0032" ArtistID="Ar_0010" CompanyID="C_5" GenreName="HipHop">
        <Title>shade</Title>
        <Price>12.00</Price> 
        <Year>2014</Year>
    </Album>

  <Album AlbumID="AL_0007" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>Love You Like A Love Song</Title>
        <Price>19.00</Price>      
        <Year>2011</Year>
    </Album>
    <Album AlbumID="AL_0008" ArtistID="Ar_0002" CompanyID="C_1" GenreName="Metal">
        <Title>Wish You Were Here</Title>
        <Price>9.00</Price>
        <Year>2008</Year>
    </Album>
    <Album AlbumID="AL_0009" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>I Like How It Feel</Title>
        <Price>13.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0010" ArtistID="Ar_0002" CompanyID="C_3" GenreName="Metal">
        <Title>J'entends la musique</Title>
        <Price>11.00</Price>
        <Year>2008</Year>
    </Album> 
  <Album AlbumID="AL_0011" ArtistID="Ar_0011" CompanyID="C_2" GenreName="Metal">
        <Title>AL7B KLO</Title>
        <Price>57.00</Price>
        <Year>2007</Year>
    </Album>
  <Album AlbumID="AL_0240" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>LAEK LAKE</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
  </Album><Album AlbumID="AL_0012" ArtistID="Ar_0012" CompanyID="C_5" GenreName="Metal">
        <Title>I like it</Title>
        <Price>12.00</Price>
        <Year>2013</Year>
    </Album>
    <Album AlbumID="AL_0013" ArtistID="Ar_0013" CompanyID="C_5" GenreName="Electro">
        <Title>I like you</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0234" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Far more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0233" ArtistID="Ar_0002" CompanyID="C_5" GenreName="Electro">
        <Title>Now here</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>
    <Album AlbumID="AL_0090" ArtistID="Ar_0002" CompanyID="C_6" GenreName="HipHop Electro">
        <Title>HABEBE</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0100" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">
        <Title>say no more</Title>
        <Price>12.00</Price> 
        <Year>2010</Year>
    </Album>

    <Album AlbumID="AL_0345" ArtistID="Ar_0006" CompanyID="C_2" GenreName="HipHop Electro">



        <Title>We Found Love</Title>
        <Price>12.00</Price>
        <Year>2005</Year>
    </Album><Album AlbumID="AL_0015" ArtistID="Ar_0002" CompanyID="C_4" GenreName="HipHop Electro">



        <Title>love is here</Title>
        <Price>6</Price>
        <Year>2005</Year>
    </Album>

  <Album AlbumID="AL_0016" ArtistID="Ar_0010" CompanyID="C_1" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2011</Year>
  </Album><Album AlbumID="AL_0066" ArtistID="Ar_0003" CompanyID="C_2" GenreName="Metal">



        <Title>take care</Title>
        <Price>5</Price>
        <Year>2005</Year>
  </Album><Album AlbumID="AL_0067" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>bad girl</Title>
        <Price>5</Price>
        <Year>2011</Year>
    </Album><Album AlbumID="AL_0076" ArtistID="Ar_0003" CompanyID="C_6" GenreName="Metal">



        <Title>it's me</Title>
        <Price>5</Price>
        <Year>2012</Year>
    </Album><Album AlbumID="AL_0056" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>I can say</Title>
        <Price>5</Price>
        <Year>2010</Year>
    </Album><Album AlbumID="AL_0055" ArtistID="Ar_0003" CompanyID="C_9" GenreName="Metal">



        <Title>when that</Title>
        <Price>5</Price>
        <Year>201</Year>
    </Album><Album AlbumID="AL_0043" ArtistID="Ar_0003" CompanyID="C_8" GenreName="Metal">



        <Title>top of top </Title>
        <Price>5</Price>
        <Year>2013</Year>
    </Album><Album AlbumID="AL_0039" ArtistID="Ar_0005" CompanyID="C_7" GenreName=" HipHop R_and_B">



        <Title>shit happens</Title>
        <Price>4</Price>
        <Year>2011</Year>
    </Album>

    <Genre GenreName="Rap"/>
    <Genre GenreName="Country"/>
    <Genre GenreName="R_and_B"/>
    <Genre GenreName="HipHop"/>
    <Genre GenreName="House"/>
    <Genre GenreName="Pop"/>
    <Genre GenreName="Electro"/>
    <Genre GenreName="Blues"/>
    <Genre GenreName="Punck"/>
    <Genre GenreName="Rock"/>
    <Genre GenreName="Metal"/>
    <Genre GenreName="Alternative_Rock"/>

  <Company CompanyID="C_1">
   CBS Records
  </Company>
  <Company CompanyID="C_2">
  RCA
  </Company>
  <Company CompanyID="C_3">
    WEA   
  </Company>
  <Company CompanyID="C_4">
  Cloumbia
  </Company>
  <Company CompanyID="C_5">
   Virgin Records 
  </Company>
  <Company CompanyID="C_6">   
  Pickwick
  </Company>
  <Company CompanyID="C_7">
   Atlantic
  </Company>
  <Company CompanyID="C_8">
   Mega
  </Company>
  <Company CompanyID="C_9">
   Grammy
  </Company>
  <Company CompanyID="C_10">
   Wordo
  </Company>
  <Company CompanyID="C_11">
    Fox
  </Company>


  <Country countryID="US">
    United State  
  </Country>
  <Country countryID="UK">
    United Kingdom
  </Country>
  <Country countryID="FR">
    France
  </Country>
  <Country countryID="GR">
    Germany
  </Country>
  <Country countryID="ME">
    Mexico
  </Country>
  <Country countryID="SP">
    Spain
  </Country>
  <Country countryID="JP">
    Japneas
  </Country>

</MusicCatalog>

<Production_by_years>
{
    for $i in distinct-values(//Album/Year)
    return element {"Year"}
    {
        element year { $i },
        for $album in //Album[Year eq $i]
        return element Title {
          attribute id { $album/@AlbumID },
          $album/*
        }
    }
}
</Production_by_years>


{
以不同的值（//Album/年）表示$i
返回元素{“年”}
{
元素年{$i}，
对于//album中的$album[年份eq$i]
返回元素标题{
属性id{$album/@AlbumID}，
$album/*
}
}
}