Notes

create table student(roll number(2), name varchar2(10),branch varchar2(2));

Table created.

SQL> create table result(roll number(2), sem number(2));

Table created.
alter table result ADD(pecentage number(2));

Table altered.
insert into student VALUES(01,'abc','cs');

1 row created.

SQL> insert into student VALUES(02,'xyz','ec');

1 row created.

select * from student natural join result;

ROLL NAME BR SEM PECENTAGE
---------- ---------- -- ---------- ----------
1 abc cs 5 90
2 xyz me 5 88

SQL> select * from student left join result on student.roll=result.pecentage;

ROLL NAME BR ROLL SEM PECENTAGE
---------- ---------- -- ---------- ---------- ----------
1 abc cs
2 xyz me

SQL> select * from student right join result on student.roll=result.pecentage;

ROLL NAME BR ROLL SEM PECENTAGE
---------- ---------- -- ---------- ---------- ----------
2 5 88
1 5 90

SQL> select * from student full join result on student.roll=result.pecentage;

ROLL NAME BR ROLL SEM PECENTAGE
---------- ---------- -- ---------- ---------- ----------
1 5 90
2 5 88
1 abc cs
2 xyz me