bring empty records in a report builder query

gistfile1.sql

-- lookup query

select 
  -1 as country_work_impact_id, 
  '[any]' as country_work_impact_name
union all
SELECT DISTINCT 
  country_work_impact_id, 
  country_work_impact_name
FROM V_Matrix_FY14_Aggregate
WHERE 
  country_work_impact_name is not null
ORDER BY 
  country_work_impact_name

-- main sql query filter

-- select ... from ... where
  AND (
		- 1 IN (@country_work_impact)
		OR country_work_impact_id IN (@country_work_impact)
		)