using xdoclet to mark a NOT NULL column

[boost]

Hi, I'm using xdoclet with my ejb's. I can't figure out how to set a column to be NOT NULL.
I am offcourse using jboss.

for instance, two tables:

table 1
user_id
username
computer_fk (references computer_id in table2, want this one to be NOT NULL)

table2
computer_id
computername


Appreciate any help.