Problems retrieving the correct values from DB from REST Web Service

I Have the following XML if I do a get to List the content of the table:

<?xml version="1.0" encoding="UTF-8"?> 
   <competitions> 
       <competition>
           <competitionPK> 
               <competitionName>Test Thing</competitionName> 
               <edition>First Thing</edition> 
           </competitionPK> 
           <description>Test Thing ONE</description>
       </competition> 
       <competition> 
           <competitionPK> 
               <competitionName>Test Thing 2</competitionName> 
               <edition>Second Thing</edition> 
           </competitionPK> 
           <description>Test Thing TWO</description> 
       </competition> 
   </competitions>

This is URL that exposes the service:

http://localhost:8080/project/org.project.rest.application.config.competition/%7Bid%7D

How can I obtain the data of only the second competition = Test Thing 2?

I've tried with:

Thanks