How to Update the Date in PL/SQL using a variable?

Question

Hi,
I am setting up a varchar of an update statement and would like to put a date variable for the value. It works when I just put SYSDATE in the statement, yet doesn't when I put the date variable. Gives me an ORA-0904 error. Thanks.
DECLARE
v_upd VARCHAR2(32767); -- update statement
l_date varchar(20);
BEGIN
select sysdate into l_date from dual;
v_upd := 'UPDATE table_name SET LAST_MODIFIED_DATE = ' ||
l_date ;
v_upd := v_upd || ' where xyz =''123'' ';
EXECUTE IMMEDIATE v_upd;
EXCEPTION
WHEN OTHERS THEN
ROLLBACK;
RAISE;
END;

Answer 1

And you don't need to select sysdate from dual.
SQL> begin
  2     UPDATE table_name
  3     SET    LAST_MODIFIED_DATE = sysdate
  4     where  xyz = '123';
  5
  6     dbms_output.put_line(sql%rowcount || ' rows updated.');
  7  end;
  8  /
55103 rows updated.
PL/SQL procedure successfully completed.