oracle不按字符顺序比较

create or replace function compareStr(v_a varchar2, v_b varchar)
  return number as
  num     number;
  v_count number;
begin
  num := -1;
  --优先匹配位数
  if length(v_a) != length(v_b) then
    return num;
  end if;
  --排重检查
  select count(*)
    into v_count
    from (select *
            from (SELECT REGEXP_SUBSTR(A, '[^,]+', 1, LEVEL) personStr
                    FROM (SELECT v_a A FROM DUAL) A
                  CONNECT BY LEVEL <= LENGTH(A) - LENGTH(REPLACE(A, ',')) + 1)
          minus
          select *
            from (SELECT REGEXP_SUBSTR(B, '[^,]+', 1, LEVEL) personStr
                    FROM (SELECT v_b B FROM DUAL) B
                  CONNECT BY LEVEL <= LENGTH(B) - LENGTH(REPLACE(B, ',')) + 1));
  if v_count = 0 then
    num := 1;
  else
    num := -1;
  end if;
  return num;
end;