Hi To All,

         I am trying to write parent to child relation ship qery between custom object and ProcessInstances and ProcessInstancesworkitems, then i need to display this all in pageblock table.

I am able to write query between custom object and ProcessInstances.it's fetching records fine.here i am unable show ProcessInstances details in page block table

<apex:page controller="approvallistclass" >
<apex:form >
<apex:pageBlock >
<apex:pageBlockTable value="{!apprlst.}" var="v">

<apex:column value="{!v.TargetObjectId }" />   I am unable to show this two fields in VF Page
<apex:column value="{!v.Status}"/>
<apex:column value="{!v.IsDeleted}"/>
</apex:pageBlockTable>
</apex:pageBlock>
</apex:form>
</apex:page>

public with sharing class approvallistclass {

public list<position__C> apprlst {get;set;}
public approvallistclass() {
apprlst = new list<Position__C>();

 This is working fine

apprlst = [select id,name,(SELECT Id,IsDeleted,Status,TargetObjectId FROM ProcessInstances) from position__C where id='a0A9000000Cbu2p'];  }  }

This is not working 

apprlst = [select id,name,(SELECT Id,IsDeleted,Status,TargetObjectId FROM ProcessInstances),(SELECT ActorId,d,IsDeleted, FROM ProcessInstanceWorkitem) from position__C where id='a0A9000000Cbu2p']  

i am getting following error.

Didn't understand relationship 'ProcessInstanceWorkitem' in FROM part of query call. If you are attempting to use a custom relationship, be sure to append the '__r' after the custom relationship name. Please reference your WSDL or the describe call for the appropriate names. at line 9 column 13

I think it may be because there is no relation ship between Position__C and procesinstanceworkitem ,but id need procesinstanceworkitem ID 

Can Any give me any idea on this query then how to dispaly that all in VF Page.