this is the table
ITEM QTY UNIT
rod1 50 cm
rod1 1 m
rod1 50 cm
rod2 25 cm
rod2 75 cm
rod2 1 m
this is the result i want user can see
ITEM QTY UNIT
rod1 2 m
rod2 2 m
this is tricky for a newbie, please help me,, thanks a lot