Getting Result from Null Query. I would like to have the document name from the query

[nabeelanwer]

select b, count(b), a from (
SELECT 'ABC Doc' as b, Region as a from table1
union all
SELECT 'DEF Doc' as b, Region as a from table2
) group by region, doc

 DOC                   	2   	REGION
 --------------------- 	--- 	--------------
 ABC			4	    South

Desire Result

 DOC                   	2   	REGION
 --------------------- 	--- 	--------------
 ABC			4	    South
 DEF			0