CREATE TABLE t1 (A INT, B INT);
CREATE TABLE t2 (A INT, C INT);

INSERT INTO t1 VALUES(1, 10);
INSERT INTO t1 VALUES(1, 20);
INSERT INTO t1 VALUES(1, 30);
SELECT * FROM t1;
----------
| A | B  |
----------
| 1	| 10 |
| 1	| 20 |
| 1	| 30 |
----------

INSERT INTO t2 VALUES(1, 110);
INSERT INTO t2 VALUES(1, 220);
INSERT INTO t2 VALUES(1, 330);
SELECT * FROM t2;
-----------
| A | C   |
-----------
| 1	| 110 |
| 1	| 220 |
| 1	| 330 |
-----------

SELECT * FROM t1 CROSS JOIN t2;
SELECT * FROM t1 INNER JOIN t2;
SELECT * FROM t1 JOIN t2;
--------------------
| A | B  | A | C   |
--------------------
| 1	| 30 | 1 | 110 |
| 1	| 20 | 1 | 110 |
| 1	| 10 | 1 | 110 |
| 1	| 30 | 1 | 220 |
| 1	| 20 | 1 | 220 |
| 1	| 10 | 1 | 220 |
| 1	| 30 | 1 | 330 |
| 1	| 20 | 1 | 330 |
| 1	| 10 | 1 | 330 |
--------------------
SELECT * FROM t1 NATURAL JOIN t2;
----------------
| A | B  | C   |
----------------
| 1	| 30 | 110 |
| 1	| 20 | 110 |
| 1	| 10 | 110 |
| 1	| 30 | 220 |
| 1	| 20 | 220 |
| 1	| 10 | 220 |
| 1	| 30 | 330 |
| 1	| 20 | 330 |
| 1	| 10 | 330 |
----------------
****************************************************************************************
****************************************************************************************
INSERT INTO t1 VALUES(1, 10);
INSERT INTO t1 VALUES(2, 20);
INSERT INTO t1 VALUES(3, 30);
SELECT * FROM t1;
----------
| A | B  |
----------
| 1	| 10 |
| 2	| 20 |
| 3	| 30 |
----------

INSERT INTO t2 VALUES(4, 40);
INSERT INTO t2 VALUES(5, 50);
INSERT INTO t2 VALUES(6, 60);
SELECT * FROM t2;
----------
| A | C  |
----------
| 4	| 40 |
| 5	| 50 |
| 6	| 60 |
----------

SELECT * FROM t1 CROSS JOIN t2;
SELECT * FROM t1 INNER JOIN t2;
SELECT * FROM t1 JOIN t2;
-------------------
| A | B  | A | C  |
-------------------
| 3	| 30 | 4 | 40 |
| 2	| 20 | 4 | 40 |
| 1	| 10 | 4 | 40 |
| 3	| 30 | 5 | 50 |
| 2	| 20 | 5 | 50 |
| 1	| 10 | 5 | 50 |
| 3	| 30 | 6 | 60 |
| 2	| 20 | 6 | 60 |
| 1	| 10 | 6 | 60 |
-------------------
SELECT * FROM t1 NATURAL JOIN t2;
Nothing