how create sequence dependent on column?
for example: have table car
make | car_no | color | model _____________________________ honda 1 s civic honda 2 b civic honda 3 w civic toyota 1 s camry toyota 2 b camry mazda 1 w 3 so car_no sequence , dependent on column make.
how can done?
if need sequential number, can generate when query:
select t.*, row_number() on (partition make order make) seqnum t; 