postgresql insert dynamic query result into table in cursor - postgresql

Question

i have the following function, that generates dynamic query and at the end i want to insert result of dynamic query into table, but the error i get is `
ERROR: query has no destination for result data
HINT: If you want to discard the results of a SELECT, use PERFORM instead.
CONTEXT: PL/pgSQL function report_get_result(integer) line 46 at SQL statement
SQL statement "SELECT report_get_result(20150131)"
PL/pgSQL function inline_code_block line 2 at PERFORM
********** Error **********'
body of the function is:
CREATE OR REPLACE FUNCTION report_get_result (
datekey integer
) returns setof logic_result_rcd
AS
$body$
DECLARE
LogicID integer;
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 execute ('SELECT "LogicID" FROM logic_table_rcd');
LOOP
FETCH cursor_logic INTO INC;
if not found then exit;
end if;
BEGIN
SELECT LogicID = "LogicID"
,SheetName = "SheetName"
,Row_ID = "Row_ID"::text
,Column_ID = "Column_ID"::text
,FromTable = "FromTable"
,Operation = "Operation"
,Amount = "Amount"
,CriteriaType_1 = CASE WHEN "CriteriaType_1" <> '' THEN ('WHERE
' || "CriteriaType_1") ELSE '' END
,Function_1 = CASE WHEN "Function_1" is null THEN 'Empty' ELSE
"Function_1" END
,Criteria_1 = CASE WHEN "Criteria_1" is null THEN 'Empty' ELSE
"Criteria_1" END
,CriteriaType_2 = CASE WHEN "CriteriaType_2" <> '' THEN ' AND '
|| "CriteriaType_2" ELSE '' END
,Function_2 = CASE WHEN "Function_2" is null THEN 'Empty' ELSE
"Function_2" END
,Criteria_2 = CASE WHEN "Criteria_2" is null THEN 'Empty' ELSE
"Criteria_2" END
,CriteriaType_3 = CASE WHEN "CriteriaType_3" <> '' THEN ' AND '
|| "CriteriaType_3" ELSE '' END
,Function_3 = CASE WHEN "Function_3" is null THEN 'Empty' ELSE
"Function_3" END
,Criteria_3 = CASE WHEN "Criteria_3" is null THEN 'Empty' ELSE
"Criteria_3" END
FROM public.logic_table_rcd WHERE "LogicID" = INC;
sql:= 'INSERT INTO public.logic_result_rcd SELECT ' || INC::text || ', 1, '
|| EntityID::text || ', ' || 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;
$body$
LANGUAGE plpgsql;

Answer 1

assign value with VAR_NAME := ''; construct, here is an example:
t=# create function f(_i int) returns table (a int) as $$
declare sql text;
begin
sql := format('select %s',_i);
return query execute sql;
end;
$$
language plpgsql
;
CREATE FUNCTION
t=# select * From f(3);
a
---
3
(1 row)