Convert SQL computer to ROLL UP sql server 2012 since its no longer support compute -

i have db this:

for meaning: lop: class sinhvien: student khoa: department monhoc: subject diemthi: mark

i want query list class , number of class belong each department

select khoa.makhoa,tenkhoa,malop,tenlop khoa,lop  khoa.makhoa=lop.makhoa  order khoa.makhoa  compute count(malop) khoa.makhoa

and result

but, sql 2012 no longer back upwards compute, said it's can done roll can't syntax, please help me

update 1: radar's result, more help

you can replace compute rollup , grouping by

select khoa.makhoa,tenkhoa,malop,tenlop , count(malop) khoa,lop  khoa.makhoa=lop.makhoa   grouping khoa.makhoa,tenkhoa,malop,tenlop rollup

sql sql-server sql-server-2012 rollup

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