SELECT
  productID
INTO
  :productID 
FROM
  ProductDelivery 
WHERE caseID IN 
  ( 
  SELECT
    caseID 
  FROM
    ProductDelivery 
  WHERE caseID = :caseID 
  
  UNION
    
  SELECT
    AppealRelationship.caseID 
  FROM
    AppealRelationship,
    ProductDelivery 
  WHERE AppealCaseID = :caseID 
    AND AppealRelationship.caseID = ProductDelivery.caseID 
  )