SELECT
  Task_wa.taskID,
  Task_wa.versionNo
INTO
  :taskID,
  :versionNo 
FROM
  Task_wa,
  TaskLink 
WHERE Task_wa.taskDefinitionID = :taskDefinitionID 
  AND Task_wa.reservedBy = :reservedBy 
  AND 
  (
    Task_wa.status <> :status 
    OR :status IS NULL 
  ) 
  AND TaskLink.taskID = Task_wa.taskID 
  AND TaskLink.linkedID = :linkedID 
  AND TaskLink.linkType = :linkType