Thread: Problem with refcursor

Hi there,

I’m running into trouble with ref cursors.

I’ve got these 2 functions, this inner one:

CREATE or replace FUNCTION f_client_getCoachingsuccessrate(p_clients refcursor,out successrate numeric, out unclearrate
numeric,out failrate numeric) AS $$ 
DECLARE
curClient record;
vNumberOfClients bigint;
vSuccessCounter BIGINT=0;
vUnclearCounter BIGINT=0;
vFailureCounter BIGINT=0;
vCurSuccessState boolean;
BEGIN
    FOR curClient IN FETCH ALL FROM p_clients LOOP
—some processing
    END LOOP;
    successrate=f_bigint_getpercentage(vSuccessCounter,vNumberOfClients);
    unclearrate=f_bigint_getpercentage(vUnclearCounter,vNumberOfClients);
    failrate=f_bigint_getpercentage(vFailureCounter,vNumberOfClients);
*/    END;
$$ LANGUAGE plpgsql;


…and this outer one:

create or replace function f_client_get3rdFeedbacksuccessrate(out successrate numeric, out unclearrate numeric, out
failratenumeric) as  
$$
DECLARE
invitedClients refcursor;
BEGIN
open invitedClients FOR SELECT c.* FROM client c join email e on e.client_id=c.id where e.textblock_id=340;
--raise notice 'all is fine so far';
Select rates.successrate,rates.unclearrate,rates.failrate from f_client_getCoachingsuccessrate(invitedClients) rates
intosuccessrate,unclearrate ,failrate; 
end;
$$
 LANGUAGE plpgsql;

Now, calling the outer one like this:

select * from f_client_get3rdFeedbacksuccessrate();

results in:

Query 1 ERROR at Line 1: : ERROR:  cannot open FETCH query as cursor
CONTEXT:  PL/pgSQL function f_client_getcoachingsuccessrate(refcursor) line 10 at FOR over SELECT rows
SQL statement "SELECT f_client_getCoachingsuccessrate(invitedClients)"
PL/pgSQL function f_client_get3rdfeedbacksuccessrate() line 8 at PERFORM

Any pointers?

Thanks, Max

Oops, of course I messed with the outer message before sending it to the list, sorry for that, so the actual error
messageis: 

ERROR:  cannot open FETCH query as cursor
CONTEXT:  PL/pgSQL function f_client_getcoachingsuccessrate(refcursor) line 10 at FOR over SELECT rows
SQL statement "Select rates.successrate,rates.unclearrate,rates.failrate from
f_client_getCoachingsuccessrate(invitedClients)rates" 
PL/pgSQL function f_client_get3rdfeedbacksuccessrate() line 7 at SQL statement

I am using PG 16.1 btw.

Max

> Am 09.01.2024 um 09:23 schrieb Maximilian Tyrtania <maximilian.tyrtania@inqua-institut.de>:
>
> Hi there,
>
> I’m running into trouble with ref cursors.
>
> I’ve got these 2 functions, this inner one:
>
> CREATE or replace FUNCTION f_client_getCoachingsuccessrate(p_clients refcursor,out successrate numeric, out
unclearratenumeric, out failrate numeric) AS $$ 
> DECLARE
> curClient record;
> vNumberOfClients bigint;
> vSuccessCounter BIGINT=0;
> vUnclearCounter BIGINT=0;
> vFailureCounter BIGINT=0;
> vCurSuccessState boolean;
> BEGIN
>    FOR curClient IN FETCH ALL FROM p_clients LOOP
> —some processing
>    END LOOP;
> successrate=f_bigint_getpercentage(vSuccessCounter,vNumberOfClients);
> unclearrate=f_bigint_getpercentage(vUnclearCounter,vNumberOfClients);
> failrate=f_bigint_getpercentage(vFailureCounter,vNumberOfClients);
> */ END;
> $$ LANGUAGE plpgsql;
>
>
> …and this outer one:
>
> create or replace function f_client_get3rdFeedbacksuccessrate(out successrate numeric, out unclearrate numeric, out
failratenumeric) as  
> $$
> DECLARE
> invitedClients refcursor;
> BEGIN
> open invitedClients FOR SELECT c.* FROM client c join email e on e.client_id=c.id where e.textblock_id=340;
> --raise notice 'all is fine so far';
> Select rates.successrate,rates.unclearrate,rates.failrate from f_client_getCoachingsuccessrate(invitedClients) rates
intosuccessrate,unclearrate ,failrate; 
> end;
> $$
> LANGUAGE plpgsql;
>
> Now, calling the outer one like this:
>
> select * from f_client_get3rdFeedbacksuccessrate();
>
> results in:
>
> Query 1 ERROR at Line 1: : ERROR:  cannot open FETCH query as cursor
> CONTEXT:  PL/pgSQL function f_client_getcoachingsuccessrate(refcursor) line 10 at FOR over SELECT rows
> SQL statement "SELECT f_client_getCoachingsuccessrate(invitedClients)"
> PL/pgSQL function f_client_get3rdfeedbacksuccessrate() line 8 at PERFORM
>
> Any pointers?
>
> Thanks, Max
>