An example(found it some time ago somewhere ?! :) ):
/*
drop view a_and_b cascade;
drop table tbla cascade;
drop table tblb cascade;
*/
CREATE TABLE tbla
( id int4 NOT NULL, a int4, b varchar(12), CONSTRAINT tbla_pk PRIMARY KEY (id)
)
--WITHOUT OIDS
;
CREATE TABLE tblb
( id int4 NOT NULL, x bool, y timestamp, CONSTRAINT tblb_pk PRIMARY KEY (id), CONSTRAINT tblb_fk FOREIGN KEY (id)
REFERENCEStbla (id) ON UPDATE CASCADE
ON DELETE CASCADE
)
--WITHOUT OIDS
;
INSERT INTO tbla VALUES ( 3, 9034, 'test1' );
INSERT INTO tbla VALUES ( 6, -23, 'test2' );
INSERT INTO tblb VALUES ( 3, false, now() );
INSERT INTO tblb VALUES ( 6, true, now() );
CREATE OR REPLACE VIEW a_and_b AS SELECT tbla.id, tbla.a, tbla.b, tblb.x, tblb.y FROM tbla
NATURAL LEFT JOIN tblb;
CREATE OR REPLACE RULE a_b_insert AS
ON INSERT TO a_and_b DO INSTEAD ( INSERT INTO tbla (id, a, b) VALUES (new.id, new.a, new.b); INSERT INTO tblb
(id,x, y) VALUES (new.id, new.x, new.y);
);
-- test your insert
INSERT INTO a_and_b VALUES (99, 123, 'text', false, now() );
CREATE OR REPLACE RULE a_and_b_del AS
ON DELETE TO a_and_b DO INSTEAD DELETE FROM tbla WHERE tbla.id = OLD.id;
-- test your delete
DELETE FROM a_and_b WHERE id=99;
CREATE OR REPLACE RULE a_and_b_upd AS
ON UPDATE TO a_and_b DO INSTEAD ( UPDATE tbla SET a = new.a, b = new.b WHERE tbla.id = new.id;
UPDATEtblb SET x = new.x, y = new.y WHERE tblb.id = new.id ; );
-- test your update
UPDATE a_and_b SET a=-333, b='neotext', x=false, y='2005-6-6' WHERE id=1;
... it works ok in pgadmin ...
PS: but for me is a problem - I can't do update from delphi7 : Error is: "row cannot be located for updating" ...
thisis because I
do 2 updates in rule of update view and the odbc driver (psqlodbc ) or
delphi wants to do update based on every field ... (also is no key in
view!!!???) ... if anybody have a solution to this problem ....!?
Best Regards,
Adrian Din,
Om Computer & SoftWare
Bucuresti, Romania
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