On 05/08/2018 05:39 AM, Philipp Kraus wrote:
Hello,
I have got a function with this definition:
CREATE OR REPLACE FUNCTION vectorize(refcursor)
RETURNS SETOF refcursor
LANGUAGE 'plpgsql'
COST 100
STABLE
ROWS 1000
AS $BODY$
begin
perform pivottable(
'_vector',
'select * from viewdata',
array['ideate', 'name', 'description', 'latitude', 'longitude'],
array['parametername'],
array['parametervalue::text', 'parametervaluetext']
);
open $1 scroll for select * from _vector;
return next $1;
end
$BODY$;
The perform call creates a dynamic column pivot table, if I run manually
select pivottable(
'_vector',
'select * from viewdata',
array['ideate', 'name', 'description', 'latitude', 'longitude'],
array['parametername'],
array['parametervalue::text', 'parametervaluetext']
);
select * from _vector;
I get all the data in the output, so everything is fine.
My goal is now to encapsulate the two lines into a function, so I define
a stable function and based on the dynamic column set a cursor. I get in
pgadmin the column names back, but the rows are empty if I run:
select * from vectorize('myvec');
fetch all from myvec;
Can you explain me, which part is wrong?
I am going to say:
perform pivottable( ...
https://www.postgresql.org/docs/10/static/plpgsql-statements.html#PLPGSQL-STATEMENTS-SQL-NORESULT
"Sometimes it is useful to evaluate an expression or SELECT query but
discard the result, for example when calling a function that has
side-effects but no useful result value. To do this in PL/pgSQL, use the
PERFORM statement:
PERFORM query;
This executes query and discards the result. ..."
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Thanks
Phil
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
