ON UPDATE CASCADE ?

[Andrej Tibaut]

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.

 

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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.

 

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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