CREATE TABLE T1 (

    ID  INTEGER NOT NULL,

    N   VARCHAR(10)

);

ALTER TABLE T1 ADD CONSTRAINT PK_T1 PRIMARY KEY (ID);



CREATE TABLE T2 (

    ID     INTEGER NOT NULL,

    T1_ID  INTEGER

);

ALTER TABLE T2 ADD CONSTRAINT PK_T2 PRIMARY KEY (ID);

ALTER TABLE T2 ADD CONSTRAINT FK_T2 FOREIGN KEY (T1_ID) REFERENCES T1 (ID);



INSERT INTO T1 (ID, N) VALUES (1, 'a');

INSERT INTO T1 (ID, N) VALUES (2, 'b');



INSERT INTO T2 (ID, T1_ID) VALUES (99, 1);

INSERT INTO T2 (ID, T1_ID) VALUES (23, 2);



CREATE VIEW VV(

    T1ID,

    T1N,

    T2ID)

AS

select t1.id, t1.n, t2.id

    from t1, t2

    where t1.id = t2.t1_id

;



select * from vv;

T1ID	T1N	T2ID

1	a	99

2	b	23

update vv set t1n='x',t2id=66  where t1id=1;

The object of the insert, delete or update statement is a view for which the 

requested operation is not permitted.

cannot update read-only view VV.

CREATE TRIGGER VV_BU0 FOR VV

ACTIVE BEFORE UPDATE POSITION 0

AS

begin

update t1 set n=new.t1n where id=new.t1id;

update t2 set ID=new.t2id where id=OLD.T2ID;

end

update vv set t1n='x',t2id=66  where t1id=1;

1 record(s) was(were) updated in T1

1 record(s) was(were) updated in T2



select * from vv;

T1ID	T1N	T2ID

1	x	66

2	b	23