日志表：

create table t_log(id number) ;

触发器1：

create or replace trigger trig_t
before  insert on t for each row
declare
begin
  insert into t_log(id) values(:new.id);
  -- commit;
end;

N@testdb1> insert into t(id) values(10) ;
insert into t(id) values(10)
*
ERROR at line 1: