On Fri, Nov 19, 2004 at 12:59:07PM +0000, Richard Huxton wrote:
> You can have what are called "savepoints" in version 8.0 though, which
> lets you trap errors and rollback to a named (saved) point in your function.
Savepoints in functions don't work as of 8.0.0beta4, unless I'm
doing something wrong:
CREATE TABLE foo (id SERIAL PRIMARY KEY, name TEXT NOT NULL);
CREATE FUNCTION fooins(TEXT) RETURNS BOOLEAN AS $$
BEGIN SAVEPOINT x; INSERT INTO foo (name) VALUES ($1); ROLLBACK TO x; RETURN TRUE;
END;
$$ LANGUAGE plpgsql;
BEGIN;
SELECT fooins('John');
ERROR: SPI_execute_plan failed executing query "SAVEPOINT x": SPI_ERROR_TRANSACTION
CONTEXT: PL/pgSQL function "fooins" line 2 at SQL statement
Error trapping does work, however:
CREATE FUNCTION fooins(TEXT) RETURNS BOOLEAN AS $$
BEGIN INSERT INTO foo (name) VALUES ($1 || '-1');
BEGIN INSERT INTO foo (id, name) VALUES (currval('foo_id_seq'), $1 || '-2'); EXCEPTION WHEN
unique_violationTHEN NULL; END;
INSERT INTO foo (name) VALUES ($1 || '-3');
RETURN TRUE;
END;
$$ LANGUAGE plpgsql;
SELECT fooins('John');fooins
--------t
(1 row)
SELECT * FROM foo;id | name
----+-------- 1 | John-1 2 | John-3
(2 rows)
--
Michael Fuhr
http://www.fuhr.org/~mfuhr/