Passing dynamic Columns to Pivot in Oracle - oracle

Question

I am new to oracle, I am trying to pass the dynamically generated column names to pivot in oracle using the below query
DECLARE
v_cols VARCHAR2(100);
v_query VARCHAR2(4000);
BEGIN
SELECT LISTAGG('''' ||product_code||'''',',') WITHIN GROUP (ORDER BY product_code)
INTO v_cols
FROM (
SELECT DISTINCT product_code
FROM pivot_test
);
v_query:='
SELECT *
FROM (
SELECT product_code,
quantity
FROM pivot_test)
PIVOT (sum(quantity) AS qunts
FOR product_code IN ('|| v_cols ||'));';
EXECUTE IMMEDIATE v_query;
--dbms_output.Put_line(v_cols);
--dbms_output.Put_line(v_query);
END;
The column generated is 'A','B','C','D' and the query generated with dynamic column is
SELECT *
FROM (
SELECT
product_code,
quantity
FROM pivot_test) PIVOT (sum(quantity) AS qunts FOR product_code IN ('A','B','C','D'));
Result:
When I take the above query and run it separately it is running correctly but when I use EXECUTE IMMEDIATE v_query; I get the error
ORA-00911: invalid character
ORA-06512: at line 20
I am not aware what is causing the problem here can any please point me what is wrong with this dynamic query execution
Value used for testing
CREATE TABLE pivot_test
(
id NUMBER,
customer_id NUMBER,
product_code VARCHAR2(5),
quantity NUMBER
);
INSERT INTO pivot_test VALUES (1,1,'A',10);
INSERT INTO pivot_test VALUES (2,1,'B',20);
INSERT INTO pivot_test VALUES (3,1,'C',30);
INSERT INTO pivot_test VALUES (4,2,'A',40);
INSERT INTO pivot_test VALUES (5,2,'C',50);
INSERT INTO pivot_test VALUES (6,3,'A',60);
INSERT INTO pivot_test VALUES (7,3,'B',70);
INSERT INTO pivot_test VALUES (8,3,'C',80);
INSERT INTO pivot_test VALUES (9,3,'D',90);
INSERT INTO pivot_test VALUES (10,4,'A',100);
COMMIT;

Answer 1

For the ORA-00911 error you need to remove the ; appended to the end of dynamically generated v_query
To display the output you can fetch the results into a cursor. The entire block can go into your dynamic SQL. A sample is below:
set serveroutput on;
declare
v_cols varchar2(100);
v_query varchar2(4000);
begin
select listagg('''' ||product_code||'''',',') within group (order by product_code) into v_cols
from(
select distinct product_code
from pivot_test
);
v_query:='
declare
cur_pivot_test sys_refcursor;
a number;
b number;
c number;
d number;
begin
open cur_pivot_test for
select * from (select product_code, quantity from pivot_test)
pivot (sum (quantity)
as qunts
for product_code in ('|| v_cols ||'));
fetch cur_pivot_Test into a, b, c, d;
close cur_pivot_test;
dbms_output.put_line (rpad(''A_QTY'',10) || '' | '' || rpad(''B_QTY'',10) || '' | '' || rpad(''C_QTY'',10) || '' | '' || rpad(''D_QTY'',10) );
dbms_output.put_line (rpad(a,10) || '' | '' || rpad(b,10) || '' | '' || rpad(c,10) || '' | '' || rpad(d,10) );
end;
';
execute immediate v_query;
end;
Output:
A_QTY | B_QTY | C_QTY | D_QTY
210 | 90 | 160 | 90