i have a data array like the under code:
day, year, brand, sale
'day1',2019,'A1',1000
'day1',2020,'A1' ,2000
'day2',2019,'A2',3000
'day2',2020,'A2',4000
'day1',2019','日合计',4000
'day2','2020','日合计',6000
when my groupcols is brand,year,i want the '日合计' groupcol is at the last.
what should i do?