如何显示共同的行(反向差异)？

A:
id | name | age
1  | Tom  | 20
2  | Bob  | 25
3  | Sam  | 30

B:
id | name | age
2  | Bob  | 25
3  | Sam  | 30

SELECT A.id, A.name, A.age
FROM A
INNER JOIN B ON A.id = B.id AND A.name = B.name AND A.age = B.age;

id | name | age
2  | Bob  | 25
3  | Sam  | 30

SELECT A.id, A.name, A.age
FROM A
LEFT JOIN B ON A.id = B.id AND A.name = B.name AND A.age = B.age;

id | name | age
1  | Tom  | 20
2  | Bob  | 25
3  | Sam  | 30

SELECT B.id, B.name, B.age
FROM A
RIGHT JOIN B ON A.id = B.id AND A.name = B.name AND A.age = B.age;

id | name | age
2  | Bob  | 25
3  | Sam  | 30