Re:

<steven_pannel@yahoo.com> writes:
> why does the following generate an error in postgresql 6.5?

> create table test2(city varchar(35) NULL );
> ERROR:  parser: parse error at or near "null"

NOT NULL is in the SQL specification.  NULL is not (it's the default
behavior and so they saw no need to specify it explicitly).

More recent versions of PG will take NULL, for compatibility with
certain not-very-standards-aware commercial products.  But leave it
out and you'll be happy.

            regards, tom lane