SQL> desc gender
Name Type        Nullable Default Comments 
---- ----------- -------- ------- -------- 
CODE INTEGER     Y                         
G    VARCHAR2(1) Y           


SQL> create or replace trigger gender_aui
  2  after insert or update on gender
  3  declare
  4   li ora_name_list_t;
  5   n  number;
  6   stmt varchar2(32767);
  7  begin
  8   n := ora_sql_txt(li);
  9   for i in 1..n loop
 10      stmt := stmt || li(i);
 11   end loop;
 12   dbms_output.put_line(stmt);
 13  end;
 14  /

Trigger created

SQL> insert into gender values (9, 'f');

insert into gender values (9, 'f')

ORA-06502: PL/SQL: numeric or value error
ORA-06512: at "RHANI.GENDER_AUI", line 7
ORA-04088: error during execution of trigger 'RHANI.GENDER_AUI'

create table GENDER
(
  CODE INTEGER,
  G    VARCHAR2(1)
);

create or replace trigger gender_aui
  after insert or update on gender  
DECLARE
  li   ora_name_list_t;
  n    NUMBER;
  stmt VARCHAR2(32767);
BEGIN
  n := ora_sql_txt(li);
  FOR i IN 1 .. n LOOP
    stmt := stmt || li(i);
  END LOOP;
  dbms_output.put_line(stmt);
END;
/

SQL> set serveroutput on
SQL> INSERT INTO GENDER VALUES(9, 'f');
INSERT INTO GENDER VALUES(9, 'f')

Creata 1 riga.

SQL> commit;

Commit completato.

SQL> 

for i in 1 .. nvl(n, 0)
loop
...

SQL> set serveroutput on;
SQL> create or replace trigger gender_aui
  2  before insert or update on gender
  3  declare
  4  li ora_name_list_t;
  5  n  number;
  6  stmt varchar2(32767);
  7  begin
  8  n := ora_sql_txt(li);
  9  for i in 1..nvl(n, 0) loop
 10  stmt := stmt || li(i);
 11  end loop;
 12  dbms_output.put_line(stmt);
 13  end;
 14  /

Trigger created

SQL> insert into gender values (3, 'f');



1 row inserted

SQL> 
SQL> create or replace trigger gender_aui
  2  after insert or update on gender
  3  declare
  4  li ora_name_list_t;
  5  n  number;
  6  stmt varchar2(32767);
  7  begin
  8  n := ora_sql_txt(li);
  9  for i in 1..nvl(n, 0) loop
 10  stmt := stmt || li(i);
 11  end loop;
 12  dbms_output.put_line(stmt);
 13  end;
 14  /

Trigger created

SQL> insert into gender values (4, 'm');



1 row inserted