> I was just wondering if anyone else has found a way to find any record in
> any and all tables in a Firebird database that should not be null, but is.

This is from my presentation on FBCon2008-Bergamo.

EXECUTE BLOCK RETURNS ("Table" VARCHAR(31), "Field" VARCHAR(31)) AS
DECLARE VARIABLE stmt VARCHAR(1000);
DECLARE VARIABLE flg INTEGER;
BEGIN
FOR SELECT R.RDB$RELATION_NAME, RF.RDB$FIELD_NAME
FROM RDB$RELATIONS R JOIN RDB$RELATION_FIELDS RF ON R.RDB$RELATION_NAME=RF.RDB$RELATION_NAME
WHERE (R.RDB$SYSTEM_FLAG = 0 OR R.RDB$SYSTEM_FLAG IS NULL) AND R.RDB$VIEW_BLR IS NULL AND R.RDB$EXTERNAL_FILE IS NULL
AND RF.RDB$UPDATE_FLAG = 1
AND (RF.RDB$NULL_FLAG = 1 OR EXISTS(SELECT * FROM RDB$FIELDS F WHERE RF.RDB$FIELD_SOURCE=F.RDB$FIELD_NAME AND
f.RDB$NULL_FLAG = 1))
ORDER BY R.RDB$RELATION_NAME, RF.RDB$FIELD_POSITION
INTO :"Table", :"Field"
DO
BEGIN
stmt = 'SELECT FIRST 1 1 FROM ' || "Table" || ' WHERE ' || "Field" || ' IS NULL';
flg = 0;
EXECUTE STATEMENT :stmt INTO :flg;
IF (flg = 1) THEN
SUSPEND;
END
END

If it is not fast enough for you, you can further enhance it to query all not-nullable fields of one table in single pass.

Ivan
http://www.volny.cz/iprenosil/interbase/