Oracle主键列自增函数

Oracle主键列自增函数DDL：

create or replace function FUNC_NEXTID
(tablename in varchar2) return number is
--pragma autonomous_transaction;
  nextid number(12);
begin
  begin
    select nvl(max(id),-1) into nextid from tSequence where upper(name) = upper(tablename); --for update;
  exception
    when no_data_found then nextid := 0;
   -- commit;
  end;

  if nextid = -1 then
    INSERT INTO tsequence(name,id) VALUES(tablename,1);
    nextid := 1;
  else
    nextid := nextid + 1;
	  update tSequence set id = nextid where upper(name) = upper(tablename);
  end if;
--  commit;
  return(nextid);
end FUNC_NEXTID;

使用方法：

insert into
infosend(ID,CreateTime,InfoType,InfoTo,InfoFrom,Title,content)
VALUES(func_nextId('InfoSend'),
sysdate,1,13905911234,'[email protected]','资讯','测试消息！');