Simeon Mitev wrote:

> how can i make a primary key field as autoincrement ? and is the
> NOT_NULL is a must for that field ?

Create ordinary field, and fill it with generator value in before insert
trigger. Most GUI tools (FlameRobin, DB Workbench,IBExpert) can create
all this for you in few clicks.

All PK fields must be NOT NULL.

--
Milan Babuskov
http://www.flamerobin.org