I have now modified my tables, my problem now is getting my own
*cascading update* trigger to work. I don't think this problem is
specific to Derby.

I recreated my tables as:
-------------------------------------------------------

DROP TABLE FREQUENCYTABLE;
DROP TABLE FOODNAMETABLE;

CREATE TABLE FOODNAMETABLE (ID SMALLINT GENERATED ALWAYS AS IDENTITY,
                           FOOD VARCHAR(40) NOT NULL PRIMARY KEY,
                           FOLDER VARCHAR(40) NOT NULL);

CREATE TABLE FREQUENCYTABLE (FREQUENCY VARCHAR(40) NOT NULL,
                            FOOD VARCHAR(40) NOT NULL,
                            AMOUNT SMALLINT NOT NULL DEFAULT 0,
                            INCLUDE SMALLINT NOT NULL DEFAULT 0 CHECK
(INCLUDE BETWEEN 0 AND 1));

CREATE TRIGGER UPDATEFOOD
      AFTER UPDATE OF FOOD ON FOODNAMETABLE
      REFERENCING OLD AS PREVIOUSROW
      FOR EACH ROW MODE DB2SQL
      UPDATE FREQUENCYTABLE SET FOOD = FOODNAMETABLE.FOOD
      WHERE FREQUENCYTABLE.FOOD = PREVIOUSROW.FOOD;

-------------------------------------------------------
The above trigger runs automatically whenever my application updates
the FOOD column
in FOODNAMETABLE, for example when the value in FOOD is changed from
*Oranges*
to *Lemons*. When this happens the trigger is supposed to change any
row in FREQUENCYTABLE
that also has *Oranges* in its FOOD column to *Lemons*, but this
doesn't happen.
By testing I have proved that the trigger runs and that it makes a
change but my
problem is it changes it to the wrong value. It seems that whereas
PREVIOUSROW.FOOD
equals *Oranges*, as expected (i.e. because that was its value before
the UPDATE on that
table), FOODNAMETABLE.FOOD doesn't equal *Lemons* as I, seemingly
incorrectly, expect.

What's wrong with the trigger?

Thanks,

MrFred.