Difference between 'Not Null' and 'Initial' in data dictionary

Hi all,

(1) If the field is defined on the database with NOT NULL as initial value, the field is filled

with the corresponding initial value.

(2) If the field is defined on the database as NOT NULL without initial value, an insert is not

possible. This results in a database error.

(3) If the field is not defined on the database as NOT NULL, there will be a NULL value in

this field.

Now i am having one question on this ..

Whenever i am creating a field in the table,the field is defined on the database as NOT NULL.

if i set initial field on then it should fill the initial values that is working fine.

but if i leave initial field as empty,and if i try to insert initial values then i should get an error but that is not happening.

And how can i define a field on the database as NOT NULL and NULL.

Thanks,

Raghunadh.K