orcale SEQUENCE

--创建SEQUENCE
CREATE SEQUENCE SEQ_GLOBAL_ID
MINVALUE 1 MAXVALUE 1.00000000000000E+27
INCREMENT BY 1
START WITH 200000 CACHE 20 NOORDER  NOCYCLE ;


--SEQUENCE引用
create or replace function F_GET_GLOBALID
return varchar2
is
  Result varchar2(20) ;
begin

    SELECT to_char(sysdate,'yyyymmdd')||to_char(seq_global_id.nextval,'FM00000000')
    INTO RESULT
    FROM DUAL   
     ;
  return(Result);
end F_GET_GLOBALID;

--检索测试
select F_GET_GLOBALID from DUAL;