>Before you do this, you'll want to ensure you can get valid metadata

from somewhere, so

>you can compare and restore the constraints later. I've been burned by

this, it

>took me a while to fix manually. I had been keeping metadata-only

exports around,

>but none were recent enough at the time. And you'd probably want a tool

like EMS

>Metadata Comparer for Interbase/Firebird so you can restore such a

metadata-only

>database, restore a no-constraint version, then fix the data, then

compare the

>two and restore the missing constraints.

Thank you Philip and Ann for all your help, I seem to have come right
now, thanks to your advice.

I restored the corrupt DB first with no check constraints, and then with
meta-data only.

I then corrected the NULL ID field in the DB with no validity checks.

I then used IBExpert DB Compare tool, which generated a script to put
all the not null's back, as the were before.

Maya