Help regarding PL/SQL collections

Question

Hi,
I have a product which is distributed in multiple countries.
  Product                    Country
PRD-1                      INDIA
PRD-1                      USA
PRD-1                      UK
PRD-2                      INDIA
PRD-2                      MALAYSIA
PRD-3                      INDIA
PRD-3                      MALAYSIA
PRD-3                      EGYPTPlease find the code that i am using
create or replace type imp_country_obj as object (
   product   VARCHAR2(30),
   country     varchar2(4000)
create or replace type imp_country_tbl as table of imp_country_obj
CREATE OR REPLACE PACKAGE prd_country_pkg
AS
   FUNCTION fn_prd_country
      RETURN imp_country_tbl;
END prd_country_pkg;
CREATE OR REPLACE PACKAGE BODY prd_country_pkg
AS
   FUNCTION fn_prd_country
      RETURN imp_country_tbl
   IS
      l_row_as_object   imp_country_obj := imp_country_obj (NULL, NULL);
      retval            imp_country_tbl := imp_country_tbl ();
      CURSOR cur_prd_country
      IS
           SELECT   p.product,
                    cursor (  SELECT   c.name
                                FROM      sp_products p1
                                       INNER JOIN
                                          countries c
                                       ON (p1.country_seq = c.country_seq)
                            GROUP BY   p1.product, c.name
                              HAVING   p1.product = p.product
                            ORDER BY   UPPER (c.name))
                       country
             FROM      sp_products p        ORDER BY   1;
      l_product         VARCHAR2 (30);
      cur_country       sys_refcursor;
      TYPE ty_country
      IS
         TABLE OF countries.name%TYPE
            INDEX BY BINARY_INTEGER;
      l_country         ty_country;
      CURSOR aa
      IS
         (SELECT   * FROM sp_trials);
      l_str             VARCHAR2 (4000);
   BEGIN
      OPEN cur_trial_country;
      LOOP
         FETCH cur_prd_country INTO   l_product, cur_country;
         EXIT WHEN cur_prd_country%NOTFOUND;
         FETCH cur_country BULK COLLECT INTO   l_country;
         l_str := '';
         FOR i IN l_country.FIRST .. l_country.LAST
         LOOP
            l_str := l_str || l_country (i) || ', ';
         END LOOP;
         l_str := SUBSTR (l_str, 1, LENGTH (l_str) - 2);
         l_row_as_object.product := l_product;
         l_row_as_object.country := l_str;
         retval.EXTEND;
         retval (retval.LAST) := l_row_as_object;
      END LOOP;
      IF cur_trial_country%ROWCOUNT = 0
      THEN
         l_row_as_object.product := NULL;
         l_row_as_object.country := NULL;
         retval.EXTEND;
         retval (retval.LAST) := l_row_as_object;
      END IF;
      RETURN retval;
      CLOSE cur_trial_country;
   END fn_prd_country;
END prd_country_pkg;
/If a country is common for multiple prodcts then it should be display in one product only. one product
Required output for my query would be:
Product                 COUNTRY
PRD-1                    INDIA, USA, UK
PRD-2                    MALAYSIA
PRD-3                    EGYPTPlease suggest me if i need to modify any changes to the code.

Answer 1

Required output for my query would be:
SQL> with t as (
select 'PRD-1' product, 'INDIA' country from dual union all
select 'PRD-1', 'USA' from dual union all
select 'PRD-1', 'UK' from dual union all
select 'PRD-2', 'INDIA' from dual union all
select 'PRD-2', 'MALAYSIA' from dual union all
select 'PRD-3', 'INDIA' from dual union all
select 'PRD-3', 'MALAYSIA' from dual union all
select 'PRD-3', 'EGYPT' from dual
select product, rtrim(xmlagg(xmlforest(country || ',' e)).extract('//text()'),',') countries
  from (select t.*, row_number () over (partition by country order by 1) rn
          from t t)
where rn = 1
group by product
PRODUCT COUNTRIES               
PRD-1   INDIA,USA,UK            
PRD-2   MALAYSIA                
PRD-3   EGYPT                   
3 rows selected.