FW: Combine sub elements in identical elements

Another try with a different send-address...

Peter.
-----Original Message-----
From: Peter Fankhauser [mailto:fankhaus@infonyte.com] 
Sent: Montag, 18. Februar 2002 14:56
To: 'Chen Yabing'; 'www-ql@w3.org'
Subject: RE: Combine sub elements in identical elements


It appears that you want to
depict only projects for which there exist suppliers for which there
exist
parts with a price > 110, within those projects you only want to return
suppliers
for which there exist parts with a price > 110, within those suppliers
you
only want to return the parts with a price > 110.
 
One way to accomplish this in XQuery is by a nested query.
 
FOR      $j IN document("spj.xml")//project[.//price >100]
RETURN 
           <project jno = {$j/@jno}>
               {FOR $s IN $j/supplier[.//price >100]
                RETURN
                    <supplier sno = {$s/@sno}> 
                        {FOR $p IN $s/part[price > 100]
                          RETURN                          
                             <part pno = {$p/@pno}> 
                                 {$p/price} 
                             </part>
                          } 
                    </supplier>
                 } 
           </project>
 
In fact, this corresponds to the (presumed) logic of your query
pretty well. If you're happy with possibly empty suppliers and
projects, you can leave out the predicates with [.//price].
 
Hope this clarifies,
 
 
Peter
 

-----Original Message-----
From: www-ql-request@w3.org [mailto:www-ql-request@w3.org] On Behalf Of
Chen Yabing
Sent: Montag, 18. Februar 2002 13:21
To: 'www-ql@w3.org'
Subject: Combine sub elements in identical elements



Hi, 

 it seems that XQuery cannot place elements together even if they have
same parent elements in the result. I mean that the result will produce
two identical elements for each sub elements.

For example, the source document: 
<db> 
        <project jno="j001"> 
                <supplier sno="s001"> 
                        <part pno="p001" > 
                                <price>190</price> 
                        </part> 
                </supplier> 
                <supplier sno="s002"> 
                        <part pno="p001"> 
                                <price>110</price> 
                        </part> 
                </supplier> 
        </project> 
        <project jno="j002"> 
                <supplier sno="s002"> 
                        <part pno="p002"> 
                                <price>120</price> 
                        </part> 
                </supplier> 
        </project> 
</db> 

the query is: 

FOR      $j IN document("spj.xml")//project, 
         $s IN $j/supplier, 
         $p IN $s/part 
WHERE    $p/price >100 
return 
           <project jno = {$j/@jno}> 
                    <supplier sno = {$s/@sno}> 
                          <part pno = {$p/@pno}> 
                                 {$p/price} 
                          </part> 
                    </supplier> 
           </project> 

and the result is: 

<project jno="j001">    
    <supplier sno="s001">      
      <part pno="p001"> 
        <price>190</price> 
      </part> 
    </supplier> 
  </project> 
  <project jno="j001">    
    <supplier sno="s002">      
      <part pno="p001"> 
        <price>110</price> 
      </part> 
    </supplier> 
  </project> 
  <project jno="j002">    
    <supplier sno="s002">      
      <part pno="p002"> 
        <price>120</price> 
      </part> 
    </supplier> 
  </project> 
</xql:result> 

In the ideal situation, the query result should be identical to the
source document. but there are two project whose jno is "j001". 

If I want to produce a result which will combine elements under the
identical parent elements together so that there are only one parent
elements. How can I do based on the above query?

Thank you!