Converting mysql "on update" to postgres "rule"

On Tue, Mar 25, 2008 at 02:51:05PM -0400, Edward Blake wrote:

CREATE RULE timestamp_update AS ON UPDATE TO visit

Do this with a trigger instead of a rule. I think there's an example in the
docs of something very similar, but I haven't checked just now.

A

Edward Blake escribió:

Thanks to everyone who's helped me before.

I'm trying to create the following mysql table in postgres:

CREATE TABLE visit (
data1 varchar(30) NOT NULL,
data2 varchar(30) DEFAULT NULL,
data3 timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE
CURRENT_TIMESTAMP);

Thus far, I've been able to get this far:
CREATE TABLE visit (
data1 varchar(30) NOT NULL,
data2 varchar(30) DEFAULT NULL,
data3 timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP);
CREATE RULE timestamp_update AS ON UPDATE TO visit
DO ALSO
UPDATE vist
SET data3 = CURRENT_TIMESTAMP;

You are in a loop...

Use a trigger that put NEW.data3 - CURRENT_TIMESTAMP

You're looking for a trigger, not a rule.

On Tue, 25 Mar 2008, Edward Blake wrote:

<snip>
|> I've tried multiple iterations of how to accomplish this and keep getting
stuck. With the one above, postgres yells and says:
|> ERROR: infinite recursion detected in rules for relation "visit"
|>
|> Any ideas?
</snip>

Look at http://www.postgresql.org/docs/8.3/interactive/plpgsql-trigger.html