Thread: Access NEW and OLD from function called by a rule
Hello,
I was wondering if it was possible to get a hold of the NEW and OLD
variables available in a Rule and pass them to a function? Maybe there
is another (better) way of accomplishing what I try to do, so I'll
sketch you my testing layout:
CREATE TABLE clients (
id SERIAL PRIMARY KEY,
name text
);
CREATE TABLE persons (
id SERIAL PRIMARY KEY,
first_name text,
last_name text
);
CREATE TABLE t_workers (
id SERIAL PRIMARY KEY,
person_id integer REFERENCES persons(id),
client_id integer REFERENCES clients(id)
);
CREATE TABLE t_contacts (
id SERIAL PRIMARY KEY,
person_id integer REFERENCES persons(id),
client_id integer REFERENCES clients(id)
);
-- view containing all worker data
CREATE VIEW workers
AS
SELECT w.*, p.first_name, p.last_name FROM t_workers AS w
INNER JOIN persons AS p ON ( w.person_id = p.id );
Now for inserting data in the workers view I created a rule:
CREATE OR REPLACE RULE insert_worker AS ON INSERT TO workers DO INSTEAD (
INSERT INTO persons ( first_name, last_name )
VALUES ( NEW.first_name, NEW.last_name );
INSERT INTO t_workers ( person_id, client_id )
VALUES ( currval('persons_id_seq'), NEW.client_id );
);
This works. Then I also have a t_contacts table where I want do the same
with, I create a view called contacts and a rule called insert_contact.
Later on I will be having more views containing data from persons. So I
thought I could make some kind of macro of the "INSERT INTO persons .."
part. I saw PostgreSQL has support for CREATE FUNCTION (something I'm
not really familiar with). This is what I wanted to do:
I create a FUNCTION to insert data into persons:
CREATE OR REPLACE FUNCTION insert_person() RETURNS OPAQUE AS '
BEGIN
INSERT INTO persons ( first_name, last_name )
VALUES ( NEW.first_name, NEW.last_name );
RETURN NULL;
END
' LANGUAGE 'plpgsql';
And I will call the FUNCTION from the isnert_worker RULE
CREATE OR REPLACE RULE insert_worker AS ON INSERT TO workers DO INSTEAD (
SELECT insert_person();
INSERT INTO t_workers ( person_id, client_id )
VALUES ( currval('persons_id_seq'), NEW.client_id );
);
If I try to insert data into workers, the following happens:
test_db=# insert into workers ( first_name, last_name ) VALUES ( 'John',
'Doe');
ERROR: record "new" is not assigned yet
DETAIL: The tuple structure of a not-yet-assigned record is indeterminate.
CONTEXT: PL/pgSQL function "insert_person" line 2 at SQL statement
PostgreSQL obviously complains about NEW not available, how can I make
it available? Is this the way to do it?
Sincerely,
Frodo Larik
Hi to all,
Actually I try to authenticate my Linux Postgres installation against Active
Directory, I find 3 solution to use:
1) LDAP
2) Pam and Kerberos
3) Kerberos alone
The first require the modification of the active directory schema, and I
prefer to avoid such responsibility.
For the 2 kerberos solution I don't find to much documentation, I try to
compile postgres with kerberos using this configure flag:
--with-krb5=/usr/
--with-includes=/usr/include/
--with-libraries=/usr/lib/
My kerberos installation is in
/usr/bin and /usr/sbin for the binary
/usr/lib/ libkrb5.* e libk5crypto.so
and libkadm5
/usr/include/ krb5.h heaser file
But seems that I miss something because when I put the krb5 word in the
pg_hba.conf and I try to connect the system give me the error:
psql -U postgres -d template1 -h 192.168.0.205
psql: Kerberos 5 authentication failed
--from the system log--
postgres[26793]: [2-1] LOG: Kerberos recvauth returned error 103
postgres[26793]: [3-1] FATAL: Kerberos5 authentication failed for user
"postgres"
postgres[26795]: [2-1] LOG: Kerberos recvauth returned error 103
postgres[26795]: [3-1] FATAL: Kerberos5 authentication failed for user
"postgres@OWORD.LOCAL"
--from the postgres log--
postgres: Software caused connection abort from krb5_recvauth
I also create with KTPASS a principal for the windows user POSTGRES and put
it in the keytab file that the configure script search for.
The kinit utility work well for any user I try to use.
After this not enthusiastics result I try with PAM and postgres (I just have
another installation that work well with pam-ldap), and sounds good, now I'm
able to authenticate the postgres user but not my and other user.
--system log--
postgres[26991]: pam_krb5: pam_sm_authenticate(postgresql ronzanid): entry:
postgres[26991]: pam_krb5: pam_sm_authenticate(postgresql ronzanid):
get_user_info(): Conversation error
postgres[26991]: pam_krb5: pam_sm_authenticate(postgresql ronzanid): exit:
failure
postgres[26991]: [2-1] LOG: pam_authenticate failed: Error in service
module
postgres[26991]: [3-1] FATAL: PAM authentication failed for user "ronzanid"
postgres[26992]: pam_krb5: pam_sm_authenticate(postgresql ronzanid): entry:
postgres[26992]: pam_krb5: pam_sm_authenticate(postgresql ronzanid):
getpwnam():
postgres[26992]: pam_krb5: pam_sm_authenticate(postgresql ronzanid): exit:
failure
postgres[26992]: [2-1] LOG: pam_authenticate failed: User not known to the
underlying authentication module
postgres[26992]: [3-1] FATAL: PAM authentication failed for user "ronzanid"
I hope someone can help, any hint, useful web pages, or documentation is
very appreciate.
Thanks in advance
Dario
Frodo Larik <lists@elasto.nl> writes:
> PostgreSQL obviously complains about NEW not available, how can I make
> it available? Is this the way to do it?
No. You seem to have read something about trigger functions, but this
usage is not a trigger function. You need to do it more like this:
regression=# CREATE OR REPLACE FUNCTION insert_person(workers) returns void as $$
regression$# begin
regression$# INSERT INTO persons ( first_name, last_name )
regression$# VALUES ( $1.first_name, $1.last_name );
regression$# end$$ language plpgsql;
CREATE FUNCTION
regression=# CREATE OR REPLACE RULE insert_worker AS ON INSERT TO workers DO INSTEAD (
regression(# SELECT insert_person(new.*);
regression(# INSERT INTO t_workers ( person_id, client_id )
regression(# VALUES ( currval('persons_id_seq'), NEW.client_id );
regression(# );
CREATE RULE
regression=# insert into workers ( first_name, last_name ) VALUES ( 'John', 'Doe');
insert_person
---------------
(1 row)
regression=#
The extra SELECT result is a bit annoying --- you could maybe hide that
by invoking the function within the rule INSERT, say by having it return
the inserted persons id.
I think passing "new.*" to a function from a rule works since about 7.4
or so.
regards, tom lane
Hi Tom,
Tom Lane wrote:
>Frodo Larik <lists@elasto.nl> writes:
>
>
>>PostgreSQL obviously complains about NEW not available, how can I make
>>it available? Is this the way to do it?
>>
>>
>
>No. You seem to have read something about trigger functions, but this
>usage is not a trigger function. You need to do it more like this:
>
>regression=# CREATE OR REPLACE FUNCTION insert_person(workers) returns void as $$
>regression$# begin
>regression$# INSERT INTO persons ( first_name, last_name )
>regression$# VALUES ( $1.first_name, $1.last_name );
>regression$# end$$ language plpgsql;
>CREATE FUNCTION
>regression=# CREATE OR REPLACE RULE insert_worker AS ON INSERT TO workers DO INSTEAD (
>regression(# SELECT insert_person(new.*);
>regression(# INSERT INTO t_workers ( person_id, client_id )
>regression(# VALUES ( currval('persons_id_seq'), NEW.client_id );
>regression(# );
>CREATE RULE
>regression=# insert into workers ( first_name, last_name ) VALUES ( 'John', 'Doe');
> insert_person
>---------------
>
>(1 row)
>
>regression=#
>
>
Thanks for tips! It works, but it seems I have to rewrite this function
for every rule??
I wanted to make te function more generic,after doing this I understand
that the argument of insert_person(workers) is a table/view name:
test_db=# CREATE OR REPLACE FUNCTION insert_person(persons) RETURNS
integer AS '
test_db'# BEGIN
test_db'# INSERT INTO persons ( first_name, last_name )
test_db'# VALUES ( $1.first_name, $1.last_name );
test_db'# RETURN currval(''persons_id_seq'');
test_db'# END
test_db'# ' LANGUAGE 'plpgsql';
CREATE FUNCTION
test_db=#
test_db=# CREATE OR REPLACE RULE insert_worker AS ON INSERT TO workers
DO INSTEAD (
test_db(# SELECT insert_person(new.*) AS person_id;
test_db(#
test_db(# INSERT INTO t_workers ( person_id, client_id )
test_db(# VALUES ( currval('persons_id_seq'), NEW.client_id );
test_db(# );
ERROR: function insert_person(workers) does not exist
HINT: No function matches the given name and argument types. You may
need to add explicit type casts.
That means I have to create functions like insert_person(workers) ,
insert_person(othertable) and function insert_person(anothertable).
Suggestions?
Sincerely,
Frodo Larik
Frodo Larik wrote:
> That means I have to create functions like insert_person(workers) ,
> insert_person(othertable) and function insert_person(anothertable).
I found the solution to this "problem". Create a function with a
Polymorphic Type (notice the anyelement):
CREATE OR REPLACE FUNCTION insert_person(anyelement) RETURNS integer AS $$
BEGIN
INSERT INTO persons ( first_name, last_name )
VALUES ( $1.first_name, $1.last_name );
RETURN currval('persons_id_seq');
END
$$ LANGUAGE 'plpgsql';
more infor here:
http://www.postgresql.org/docs/8.0/interactive/extend-type-system.html#EXTEND-TYPES-POLYMORPHIC
sincerely,
Frodo Larik