create temp table in rule

Is it possible to create a temporary table within a rule?

I get a syntax error near 'CREATE TEMPORARY TABLE' if I try to do the
following:

CREATE RULE id_insert_rule AS
ON INSERT TO id_insert
DO INSTEAD
(
CREATE TEMPORARY TABLE id_temp (
LIKE
id )
ON COMMIT DELETE ROWS;

INSERT INTO id_temp (
username,
pass_md5,
pass_sha1 )
VALUES
new.username,
encode( digest( new.password, 'md5' ), 'hex' ),
encode( digest( new.password, 'sha1' ), 'hex' );

DELETE FROM
id
USING
id_temp
WHERE
id.username = id_temp.username;

INSERT INTO
id
SELECT
*
FROM
id_temp;
);

As you can see, I'm trying to create a simple 'insert or update' rule.

--
Ron Peterson
Network & Systems Manager
Mount Holyoke College
http://www.mtholyoke.edu/~rpeterso