SQL Server, Primavera P6 Professional

SELECT
p.proj_id,
p.proj_short_name,
x.wbs_name as project_name,
p.plan_start_date,
p.plan_end_date
FROM project p join (select distinct w.proj_id, w.wbs_name
from PROJWBS w left join task t on w.proj_id = t.proj_id and w.wbs_id = t.wbs_id
where w.parent_wbs_id not in (select wbs_id from PROJWBS where proj_id = w.proj_id)) x
on p.proj_id=x.proj_id
--WHERE proj_id = @ProjectID;