xquery - Xquery中的分组和计数

Question

听说是XML。我正在尝试获取由作者发布的标题的数量，日期范围为 2012年2月15日至2012年2月24日，从高到低(标题数)。

<entries>
<entry>
    <id>1</id>
    <published>23/02/2012</published>
    <title>Title 1</title>
    <content type="html">This is title one</content>
    <author>
        <name>Pankaj</name>
    </author>
</entry>
<entry>
    <id>2</id>
    <published>22/02/2012</published>
    <title>Title 2</title>
    <content type="html">This is title two</content>
    <author>
        <name>Pankaj</name>
    </author>
</entry>
<entry>
    <id>3</id>
    <published>21/02/2012</published>
    <title>Title 3</title>
    <content type="html">This is title three</content>
    <author>
        <name>Rob</name>
    </author>
</entry>
<entry>
    <id>4</id>
    <published>20/02/2012</published>
    <title>Title 4</title>
    <content type="html">This is title four</content>
    <author>
        <name>Bob</name>
    </author>
</entry>
<entry>
    <id>5</id>
    <published>19/02/2012</published>
    <title>Title 1</title>
    <content type="html">This is title five</content>
    <author>
        <name>Pankaj</name>
    </author>
</entry>

我正在尝试从xquery获取输出:

<?xml version="1.0" encoding="UTF-8"?>
<results>
<result>
    <author>
        <name>Pankaj</name>
    </author>
    <numberOfTitles>3</numberOfTitles>
</result>
<result>
    <author>
        <name>Rob</name>
    </author>
    <numberOfTitles>1</numberOfTitles>
</result>
<result>
    <author>
        <name>Bob</name>
    </author>
    <numberOfTitles>1</numberOfTitles>
</result>

请帮我..

Answer 1

此XQuery 1.0解决方案可由任何兼容的XQuery 1.0处理器执行:

注意:不使用group by和distinct-values()。

<results> 
 {
 let $entries := 
    /*/entry
           [for $d in 
                    xs:date(string-join(reverse(tokenize(published, '/')), '-'))
                return
                   xs:date('2012-02-15') le $d and $d le xs:date('2012-02-24')
             ],

  $vals := $entries/author/name
      return
         for $a in  $vals[index-of($vals, .)[1]],
                $cnt in count(index-of($vals, $a)) 
           order by $cnt descending
             return
              <result>
                <author>
                  {$a}
                 </author>
                 <numberOfTitles>
                   {count(index-of($vals, $a))}
                 </numberOfTitles>
              </result>
    }
</results>

应用于提供的XML文档时 :

<entries>
    <entry>
        <id>1</id>
        <published>23/02/2012</published>
        <title>Title 1</title>
        <content type="html">This is title one</content>
        <author>
            <name>Pankaj</name>
        </author>
    </entry>
    <entry>
        <id>2</id>
        <published>22/02/2012</published>
        <title>Title 2</title>
        <content type="html">This is title two</content>
        <author>
            <name>Pankaj</name>
        </author>
    </entry>
    <entry>
        <id>3</id>
        <published>21/02/2012</published>
        <title>Title 3</title>
        <content type="html">This is title three</content>
        <author>
            <name>Rob</name>
        </author>
    </entry>
    <entry>
        <id>4</id>
        <published>20/02/2012</published>
        <title>Title 4</title>
        <content type="html">This is title four</content>
        <author>
            <name>Bob</name>
        </author>
    </entry>
    <entry>
        <id>5</id>
        <published>19/02/2012</published>
        <title>Title 1</title>
        <content type="html">This is title five</content>
        <author>
            <name>Pankaj</name>
        </author>
    </entry>
</entries>

产生所需的正确结果:

<?xml version="1.0" encoding="UTF-8"?>
<results>
   <result>
      <author>
         <name>Pankaj</name>
      </author>
      <numberOfTitles>3</numberOfTitles>
   </result>
   <result>
      <author>
         <name>Rob</name>
      </author>
      <numberOfTitles>1</numberOfTitles>
   </result>
   <result>
      <author>
         <name>Bob</name>
      </author>
      <numberOfTitles>1</numberOfTitles>
   </result>
</results>