create table main2(Name varchar(256), marks int);
insert into main2(Name, marks)values('Dheerendra',87);
insert into main2(Name, marks)values('Jitendra',97);
select * from main2;

create table backup2(Name varchar(256), marks int);

create or replace trigger tb
before delete on main2
for each row
begin
Insert into backup2 values(:old.Name, :old.marks);
end;
/

delete from main2 where Name='Dheerendra';

select * from main2;
select * from backup2;