带有序列和触发器的 oracle 自动增量无法正常工作

here is my problemI have this code to make an autoincrement variable in oracle database:

CREATE TABLE Korisnici
    (
        id_korisnika number PRIMARY KEY,
        ime_korisnika varchar2(200),
        prezime_korisnika varchar2(200),
        broj_telefona varchar2(30),
        adresa_korisnika varchar2(400)
    )
    /

create sequence test_seq
start with 1 
increment by 1;

CREATE OR REPLACE TRIGGER test_trigger
BEFORE INSERT ON Korisnici FOR EACH ROW
BEGIN
  SELECT test_seq.NEXTVAL
  INTO :NEW.id_korisnika
  FROM DUAL;
END;
/

如果我从头开始一切都很好，我的数字为 1,2,3,4....我关闭程序，再次打开，oracle 数据库连接再次启动.我再添加一个输入，我有像 20、21、22、23 这样的数字......我把程序放在我的 android 上并从不同的设备连接，当我输入一个用户时，我有 30,31,33,34...

CREATE OR REPLACE PROCEDURE Citanje_korisnika( p_rc OUT SYS_REFCURSOR )
AS
BEGIN
  OPEN p_rc
   FOR SELECT *
         FROM Korisnici;
END;

create sequence test_seq
start with 1 
increment by 1
NOCACHE;