mysql workbench trying to produce a set of results that i can't figure out : I need the query to produce this:
person_idlast_name first_name region_id	region name	   year	 month amount_sold				
  1		barnum        phineas      	1		maricopa        2016	1	800000				
  1		barnum        phineas      	1		maricopa        2016	2	850000				
  1		barnum        phineas      	1		maricopa        2016	3	990000				
  2		loman         willy        	2		pima            2016	1	425000				
  2		loman         willy        	2		pima            2016	2	440000				
  2		loman         willy        	2		pima            2016	3	450000				
  2		loman         willy        	3		pinal           2016	1	200000				
  2		loman         willy        	3		pinal           2016	2	210000				
  2		loman         willy        	3		pinal           2016	3	220000				
  2		loman         willy        	4		santa cruz      2016	1	50000				
  2		loman         willy        	4		santa cruz      2016	2	52000				
  2		loman         willy        	4		santa cruz      2016	3	55000				
  3		kay           mary         	5		cochise         2016	1	40000				
  3		kay           mary         	5		cochise         2016	2	41000				
  3		kay           mary         	5		cochise         2016	3	42000				
  3		kay           mary         	6		gila            2016	1	 3000				
  3		kay           mary         	6		gila            2016	2	31000				
  3		kay           mary         	6		gila            2016	3	32000				
  3		kay           mary         	7		graham          2016	1	20000				
  3		kay           mary         	7		graham          2016	2	21000				
  3		kay           mary         	7		graham          2016	3	22000				
  4		lillian       vernon       	NULL		NULL		NULL	NULL	NULL	checksum 4,994,000 

I have this code written:
select person_id, last_name, first_name,

sales_region.Region_id, name AS 'Region Name',

year, month, amount_sold
from sales

join sales_people

on person_id = person_id

join sales_region

on sales_region.region_id = sales_region.region_id
group by  month asc, region_id, person_id

order by person_id, region_id, month asc
;

i do not get a check sum and the last persons items do not come in null.
