Hi All,
I recently had a need to have conditional update rules on a view. This
didn't work too well:
CREATE RULE insert_one AS
ON INSERT TO one WHERE NEW.id IS NULL
DO INSTEAD (
INSERT INTO _simple (id, guid, state, name, description)
VALUES (NEXTVAL('seq_kinetic'), NEW.guid, NEW.state, NEW.name,
NEW.description);
INSERT INTO simple_one (id, bool)
VALUES (CURRVAL('seq_kinetic'), NEW.bool);
);
CREATE RULE promote_one AS
ON INSERT TO one WHERE NEW.id IS NOT NULL
DO INSTEAD (
UPDATE _simple
SET guid = NEW.guid, state = NEW.state, name = NEW.name,
description = NEW.description
WHERE id = NEW.id;
INSERT INTO simple_one (id, bool)
VALUES (NEW.ID, NEW.bool);
);
I found this in the docs to explain the issue:
> There is a catch if you try to use conditional rules for view updates:
> there must be an unconditional INSTEAD rule for each action you wish
> to allow on the view.
Well, I didn't have an unconditional update rule, so I added one
without removing the other two:
CREATE RULE nothing_one AS
ON INSERT TO one DO INSTEAD NOTHING;
And it worked! Now I can have an insert do an INSERT or UPDATE on
another table magically.
But my question is this: Is this a known and supported behavior? If
not, is it likely to change? If so, how is the order or rules evaluated
when a query is sent to the database? Order of definition?
Alphabetically?
TIA,
David
PS: Please Cc me in replies as I am not subscribed to the list. Thanks!
