postgresql cannot open INSERT query as cursor - postgresql

Question

i'm trying to generate dynamic query to insert results of dynamic select into table. my code is the following.
CREATE OR REPLACE FUNCTION public.report_get_result(
datekey integer)
RETURNS setof public.logic_result_rcd
LANGUAGE 'plpgsql'
COST 100
VOLATILE
AS $BODY$
DECLARE
LogicID text;
SheetName text;
Row_ID text;
Column_ID text;
FromTable text;
Operation text;
Amount text;
CriteriaType_1 text;
Function_1 text;
Criteria_1 text;
CriteriaType_2 text;
Function_2 text;
Criteria_2 text;
CriteriaType_3 text;
Function_3 text;
Criteria_3 text;
sql text;
INC Integer;
begin
DROP TABLE IF EXISTS loans;
create temp table loans as
select * from loan.vfact_state_principal where "DateKey" = datekey;
DECLARE cursor_logic REFCURSOR;
BEGIN
OPEN cursor_logic for SELECT "LogicID" FROM logic_table_rcd;
LOOP
FETCH cursor_logic INTO INC;
if not found then exit;
end if;
BEGIN
select into LogicID "LogicID" from public.logic_table_rcd WHERE
"LogicID" = 1;
select into SheetName "SheetName" from public.logic_table_rcd WHERE
"LogicID" = 1;
select into Row_ID "Row_ID" from public.logic_table_rcd WHERE "LogicID"
= 1;
select into Column_ID "Column_ID" from public.logic_table_rcd WHERE
"LogicID" = 1;
select into FromTable "FromTable" from public.logic_table_rcd WHERE
"LogicID" = 1;
select into Operation "Operation" from public.logic_table_rcd WHERE
"LogicID" = 1;
select into Amount "Amount" from public.logic_table_rcd WHERE "LogicID"
= 1;
select into CriteriaType_1 CASE WHEN "CriteriaType_1" <> '' OR
"CriteriaType_1" is not null THEN (' WHERE "' || "CriteriaType_1" || '"')
ELSE '' END from public.logic_table_rcd WHERE "LogicID" = 1;
select into Function_1 CASE WHEN "Function_1" is null THEN '' ELSE
"Function_1" END from public.logic_table_rcd WHERE "LogicID" = 1;
select into Criteria_1 CASE WHEN "Criteria_1" is null THEN '' ELSE
"Criteria_1" END from public.logic_table_rcd WHERE "LogicID" = 1;
select into CriteriaType_2 CASE WHEN "CriteriaType_2" <> '' OR
"CriteriaType_2" is not null THEN ' AND "' || "CriteriaType_2" || '"' ELSE
'' END from public.logic_table_rcd WHERE "LogicID" = 1;
select into Function_2 CASE WHEN "Function_2" is null THEN '' ELSE
"Function_2" END from public.logic_table_rcd WHERE "LogicID" = 1;
select into Criteria_2 CASE WHEN "Criteria_2" is null THEN '' ELSE
"Criteria_2" END from public.logic_table_rcd WHERE "LogicID" = 1;
select into CriteriaType_3 CASE WHEN "CriteriaType_3" <> '' or
"CriteriaType_3" is not null THEN ' AND "' || "CriteriaType_3" || '"' ELSE
'' END from public.logic_table_rcd WHERE "LogicID" = 1;
select into Function_3 CASE WHEN "Function_3" is null THEN '' ELSE
"Function_3" END from public.logic_table_rcd WHERE "LogicID" = 1;
select into Criteria_3 CASE WHEN "Criteria_3" is null THEN '' ELSE
"Criteria_3" END from public.logic_table_rcd WHERE "LogicID" = 1;
sql:= 'INSERT INTO public.logic_result_rc SELECT ' || INC::text || ', 1, '
|| DateKey::text || ', ''' || 'RCD' || ''', ''' || SheetName::text || ''', '
|| Row_ID::text || ', '
|| Column_ID::text || ', ' || Operation || '("' || Amount || '")' || ' FROM
' || FromTable
|| CriteriaType_1 || ' ' || Function_1 || ' ' || Criteria_1
|| CriteriaType_2 || ' ' || Function_2 || ' ' || Criteria_2
|| CriteriaType_3 || ' ' || Function_3 || ' ' || Criteria_3;
RETURN QUERY EXECUTE sql;
END;
END LOOP;
CLOSE cursor_logic;
END;
END;
$BODY$;
ALTER FUNCTION public.report_get_result(integer)
OWNER TO postgres;
But after execution I get the next error:
cannot open INSERT query as cursor
All variables are assigned correctly. may be insert must be somewhere else outside cursor? does INSERT INTO .... FETCH ALL statement exist?

Answer 1

INSERT by default doesn't return any rows, so there is nothing to fetch. You can fix this by appending your sql string with RETURNING *, with should return contents inserted into public.logic_result_rc.
So it would like this: RETURN QUERY EXECUTE concat(sql, ' RETURNING *');
Basic syntax is:
INSERT INTO table_name ( column_name [, ...] )
VALUES ( ) | query
RETURNING * --or list of columns, same syntax like for SELECT