Hi,
While testing event triggers support for CREATE RULE, I noticed that
existing code does not deparse whole-row references correctly:
postgres=# create table f (a int);
CREATE TABLE
postgres=# create table g (other f);
CREATE TABLE
postgres=# create rule f as on insert to f do also (insert into g values (new));
CREATE RULE
postgres=# \d f
Tabla «public.f»
Columna | Tipo | Modificadores
---------+---------+---------------
a | integer |
Reglas:
f AS
ON INSERT TO f DO INSERT INTO g (other)
VALUES (new.*)
Note that my rule had "values (new)" but the deparsed version uses
"VALUES (new.*)" which doesn't work on input: pg_dump will fail with
this output:
$ pg_dump postgres -t f -t g | LC_ALL=C PGOPTIONS="-c lc_messages=C" psql
postgres2
SET
SET
SET
SET
SET
SET
SET
SET
SET
CREATE TABLE
ALTER TABLE
CREATE TABLE
ALTER TABLE
ERROR: column "other" is of type f but expression is of type integer
LINE 3: VALUES (new.*);
^
HINT: You will need to rewrite or cast the expression.
My sample session with event triggers is a neat example of that
functionality at work BTW (or so I think anyway):
alvherre=# CREATE RULE "F" AS ON INSERT TO public.f DO also (insert into g
values (new); insert into h values (new); insert into i values (new));
NOTICE: Trigger has been executed. ddl_command_end -- CREATE RULE
NOTICE: JSON blob: {
"actions": [
"INSERT INTO public.g (duh) VALUES (new.*)",
"INSERT INTO public.h (duh) VALUES (new.*)",
"INSERT INTO public.i (duh) VALUES (new.*)"
],
"event": "INSERT",
"fmt": "CREATE %{or_replace}s RULE %{identity}I AS ON %{event}s TO
%{table}D %{where_clause}s DO %{instead}s (%{actions:; }s)",
"identity": "F",
"instead": "ALSO",
"or_replace": "",
"table": {
"objname": "f",
"schemaname": "public"
},
"where_clause": {
"clause": null,
"fmt": "WHERE %{clause}s",
"present": false
}
}
NOTICE: expanded: CREATE RULE "F" AS ON INSERT TO public.f DO ALSO (INSERT
INTO public.g (duh) VALUES (new.*); INSERT INTO public.h (duh) VALUES (new.*);
INSERT INTO public.i (duh) VALUES (new.*))
CREATE RULE
alvherre=# \d f
Tabla «public.f»
Columna | Tipo | Modificadores
---------+---------+---------------
a | integer |
Reglas:
"F" AS
ON INSERT TO f DO ( INSERT INTO g (duh)
VALUES (new.*);
INSERT INTO h (duh)
VALUES (new.*);
INSERT INTO i (duh)
VALUES (new.*);
)
I'm switching to the multixact bug now, but I wanted to report this
before I forgot it.
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
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