Platform: IB5.6 SCO

Running the following SQL within ESQL:

UPDATE person b
SET status = 'Z'
WHERE EXISTS (SELECT a.id FROM
persontype a
WHERE mydate < (SELECT mydate FROM details)
AND a.id = b.id)
AND b.status != 'Z';

Note: table details only contains 1 row.

gives the error:
-625 - The insert failed because a column defined includes validation
constraints.

according to the manual a -625 is:
Validation error for column <string>, value <string>.

Now, Running the same SQL from within isql works fine.

Has anybody come across this before?

thanks
bill