create or replace package body n_pk_string as

  function of_globalreplace(avc_source varchar2, avc_old varchar2, avc_new varchar2) return varchar2 as
  begin
    if avc_source is null or avc_old is null or avc_new is null then
      return null;
    end if;
    return of_globalreplace(avc_source, avc_old, avc_new, true);
  end of_globalreplace;
  
  function of_globalreplace(avc_source varchar2, avc_old varchar2, avc_new varchar2, ab_ignorecase boolean) return varchar2 as
  begin
    declare
      lvc_source varchar2(200);
      lvc_old varchar(20);
    begin
      --Check parameters
      if avc_source is null or avc_old is null or avc_new is null or ab_ignorecase is null then
        return null;
      end if;
      
      lvc_source := avc_source;
      lvc_old := avc_old;
      
      if ab_ignorecase then
        lvc_source := lower(lvc_source);
        lvc_old := lower(lvc_old);
      end if;
      
      return replace(lvc_source, lvc_old, avc_new);
    end;
  end of_globalreplace;

  function of_countoccurrences(avc_source varchar2, avc_target varchar2) return number as
  begin
    declare
      ln_count number;
    begin
      --Check for parameters
      if avc_source is null or avc_target is null then
        return null;
      end if;
      --Default is to ignore case.
      ln_count := of_countoccurrences(avc_source, avc_target, true);
      return ln_count;
    end;
  end of_countoccurrences;

  function of_countoccurrences(avc_source varchar2, avc_target varchar2, ab_ignorecase boolean) return number as
  begin
    declare
      ln_count number;
      ln_pos number;
      ln_len number;
      lvc_source varchar2(200);
      lvc_target varchar2(50);
    begin
      -- Check for parameters
      if avc_source is null or avc_target is null or ab_ignorecase is null then
        return null;
      end if;
      
      --Should function ignore case:1
      lvc_source := avc_source;
      lvc_target := avc_target;
      if ab_ignorecase then
        lvc_source := lower(avc_source);
        lvc_target := lower(avc_target);
      end if;
      
      ln_len := length(lvc_target);
      ln_count := 0;
      
      ln_pos := instr(lvc_source, lvc_target);
      
      while ln_pos > 0 loop
        ln_count := ln_count + 1;
        ln_pos := instr(lvc_source, lvc_target, (ln_pos + ln_len));
      end loop;
      
      return ln_count;
    end;
  end of_countoccurrences;

end n_pk_string;