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Thread: rule calls function, passing OLD

rule calls function, passing OLD

From
R.Welz
Date:
Hello.
I am a beginner with pgsql and struggeling with the documentation.

Why can't I pass OLD from my rule to the function so the function knows
on which row the rule was called?


test=# \i '/home/myAccount/Documents/Datenbank Layout/Postgres
Sytax/test/Regeln2'
CREATE FUNCTION
psql:/home/myAccount/Documents/Datenbank Layout/Postgres
Sytax/test/Regeln2:16: ERROR:  function
deny_namen_telefonverweise(namen_telefonverweise) does not exist
HINT:  No function matches the given name and argument types. You may
need to add explicit type casts.
test=#


When I pass an integer instead, everything works.

Is there another way of letting the function know on which row the rule
was called?



CREATE OR REPLACE FUNCTION deny_namen_telefonverweise(record) RETURNS
void AS '
    DECLARE
    result RECORD;

    BEGIN
    /* DELETE ROW LATER */
    SELECT 1+1;

    END;
    '
    LANGUAGE 'plpgsql';


CREATE OR REPLACE RULE deny_namen_Telefonverweise AS ON DELETE TO
Namen_Telefonverweise
DO INSTEAD
SELECT DENY_Namen_Telefonverweise(OLD);

Re: rule calls function, passing OLD

From
Stephan Szabo
Date:
On Wed, 14 Jul 2004, R.Welz wrote:

> test=# \i '/home/myAccount/Documents/Datenbank Layout/Postgres
> Sytax/test/Regeln2'
> CREATE FUNCTION
> psql:/home/myAccount/Documents/Datenbank Layout/Postgres
> Sytax/test/Regeln2:16: ERROR:  function
> deny_namen_telefonverweise(namen_telefonverweise) does not exist
> HINT:  No function matches the given name and argument types. You may
> need to add explicit type casts.

I'd think you'd want the function declared as above (using the specific
rowtype), not as one taking record, which appears to work for me.

> CREATE OR REPLACE FUNCTION deny_namen_telefonverweise(record) RETURNS
> void AS '
>     DECLARE
>     result RECORD;
>
>     BEGIN
>     /* DELETE ROW LATER */
>     SELECT 1+1;
>
>     END;
>     '
>     LANGUAGE 'plpgsql';
>
>
> CREATE OR REPLACE RULE deny_namen_Telefonverweise AS ON DELETE TO
> Namen_Telefonverweise
> DO INSTEAD
> SELECT DENY_Namen_Telefonverweise(OLD);

Re: rule calls function, passing OLD

From
Tom Lane
Date:
"R.Welz" <linuxprodukte@gmx.de> writes:
> CREATE OR REPLACE FUNCTION deny_namen_telefonverweise(record) RETURNS
> void AS '
> ...
>     LANGUAGE 'plpgsql';

You can't do that.  CVS tip tells you so immediately:
    ERROR:  plpgsql functions cannot take type record
but I think 7.4 wouldn't notice until you try to execute the function.

You could declare the function as taking the specific rowtype of the
table, though:

CREATE OR REPLACE FUNCTION deny_namen_telefonverweise(Namen_Telefonverweise) RETURNS

Notice that the error message you're getting is specifically complaining
about the lack of such a function.

            regards, tom lane