Hi to everyone. I'll try to explain my problem with an example.
-- I've got 2 tables and one view CREATE TABLE a (name varchar(20) primary key, num integer); CREATE TABLE b (town varchar(15), name varchar(20) references a(name));
insert into a values ('tom',5); insert into a values ('paul',99); insert into a values ('jack',1234); insert into b values ('london','tom'); insert into b values ('rome','paul');
CREATE VIEW vvv AS SELECT * FROM a NATURAL JOIN b;
-- I've crated a rule in this way
CREATE RULE rrr AS ON INSERT TO vvv WHERE NEW.name = 'tom' DO INSTEAD INSERT INTO a VALUES (NEW.name, NEW.num);
Trying a simple INSERT INTO vvv, I receive this message: ERROR: cannot insert into a view HINT: You need an unconditional ON INSERT DO INSTEAD rule.
If I've understood well, the qualification (WHERE NEW.name = 'tom') is the condition under which the rule has to be executed. Only if the condition is met, the rule is executed. I noticed that if I remove the qualification, the rule works, but doing so I am not able anymore to test the condition. (I could overcame this problem with a trigger, but I'd prefer if someone could explain me how to do this with rules).
