ON UPDATE CASCADE ?

[Andrej Tibaut <an...@uni-mb.si>]

I have setup the following database. It contains two tables with two columns
each. The first table (VrstaPrevoza) is a parent table to the second one
(VozniRedi) via foreign key on field VrstaId. I want the changes (updates)
to the VrstaPrevoza.VrstaId to be propagated to the child table VozniRedi. 
The UPDATE statement results in an error.
 
------------------------
 
My code:
 
DRIVER 'org.apache.derby.jdbc.EmbeddedDriver';
CONNECT 'jdbc:derby:database/test;create=true';

-- VrstaPrevoza
DROP TABLE VrstaPrevoza;
CREATE TABLE VrstaPrevoza (VrstaId CHAR(2) NOT NULL, 
                           Opis VARCHAR(20) NOT NULL, 
                          PRIMARY KEY (VrstaId));
INSERT INTO VrstaPrevoza VALUES ('MK','bla bla');
INSERT INTO VrstaPrevoza VALUES ('PR','bla bla');
INSERT INTO VrstaPrevoza VALUES ('MN','bla bla');
 
-- VozniRedi
DROP TABLE VozniRedi;
CREATE TABLE VozniRedi (VozniRedId VARCHAR(50) NOT NULL, 
   VrstaId CHAR(2)  NOT NULL,
                    PRIMARY KEY (VozniRedId),
   FOREIGN KEY (VrstaId) REFERENCES VrstaPrevoza(VrstaId));
INSERT INTO VozniRedi VALUES ('MK1110010R','MK');
INSERT INTO VozniRedi VALUES ('MK1110020R','MK');
 
 
 
ij> UPDATE VrstaPrevoza SET VrstaId='AB' WHERE VrstaId='MK';
ERROR 23503: UPDATE on table 'VRSTAPREVOZA' caused a violation of foreign
key co
nstraint 'SQL050403042438881' for key (MK).  The statement has been rolled
back.
 
-------------------------------
 
I would expect to be able to define the foreign key like
FOREIGN KEY (VrstaId) REFERENCES VrstaPrevoza(VrstaId) ON UPDATE CASCADE;
but this doesn't work in Derby.
 
How to implement "UPDATE CASCADE"??
 
Many thanks!
 
Andrej