mysql> select * from test;

+----+------------+-------+-----------+

| id | name       | score | subject   |

+----+------------+-------+-----------+

|   | xiaoming   |     | shuxue    |

|   | xiaohong   |     | shuxue    |

|   | xiaohong   |     | english   |

|   | xiaohong   |     | physics   |

|   | xiaohong   |     | astronaut |

|   | xiaoming   |     | physics   |

|   | xiaoming   |     | astronaut |

|   | xiaoming   |     | english   |

|   | xiaobai    |     | astronaut |

|  | .2xiaobai |     | english   |

|  | .2xiaobai |     | physics   |

|  | 3xiaobai   |     | shuxue    |

|  | 123xiaohei |     | astronaut |

|  | xiaohei    |     | shuxue    |

|  | xiaohei    |     | physics   |

|  | .12xiaohei |     | english   |

+----+------------+-------+-----------+

 rows in set (0.00 sec)

mysql> select * from user;

+------+----------+-----------+

| id   | name     | address   |

+------+----------+-----------+

|     | xiaoming | beijing   |

|     | xiaobai  | shandong  |

|     | xiaohong | suzhou    |

|     | xiaohei  | changchun |

+------+----------+-----------+

 rows in set (0.00 sec)

mysql> select * from user left join test on user.name=test.name;

+------+----------+-----------+------+----------+-------+-----------+

| id   | name     | address   | id   | name     | score | subject   |

+------+----------+-----------+------+----------+-------+-----------+

|     | xiaoming | beijing   |     | xiaoming |     | shuxue    |

|     | xiaohong | suzhou    |     | xiaohong |     | shuxue    |

|     | xiaohong | suzhou    |     | xiaohong |     | english   |

|     | xiaohong | suzhou    |     | xiaohong |     | physics   |

|     | xiaohong | suzhou    |     | xiaohong |     | astronaut |

|     | xiaoming | beijing   |     | xiaoming |     | physics   |

|     | xiaoming | beijing   |     | xiaoming |     | astronaut |

|     | xiaoming | beijing   |     | xiaoming |     | english   |

|     | xiaobai  | shandong  |     | xiaobai  |     | astronaut |

|     | xiaohei  | changchun |    | xiaohei  |     | shuxue    |

|     | xiaohei  | changchun |    | xiaohei  |     | physics   |

+------+----------+-----------+------+----------+-------+-----------+

 rows in set (0.00 sec)

mysql> select * from user right join test on user.name=test.name;

+------+----------+-----------+----+------------+-------+-----------+

| id   | name     | address   | id | name       | score | subject   |

+------+----------+-----------+----+------------+-------+-----------+

|     | xiaoming | beijing   |   | xiaoming   |     | shuxue    |

|     | xiaoming | beijing   |   | xiaoming   |     | physics   |

|     | xiaoming | beijing   |   | xiaoming   |     | astronaut |

|     | xiaoming | beijing   |   | xiaoming   |     | english   |

|     | xiaobai  | shandong  |   | xiaobai    |     | astronaut |

|     | xiaohong | suzhou    |   | xiaohong   |     | shuxue    |

|     | xiaohong | suzhou    |   | xiaohong   |     | english   |

|     | xiaohong | suzhou    |   | xiaohong   |     | physics   |

|     | xiaohong | suzhou    |   | xiaohong   |     | astronaut |

|     | xiaohei  | changchun |  | xiaohei    |     | shuxue    |

|     | xiaohei  | changchun |  | xiaohei    |     | physics   |

| NULL | NULL     | NULL      |  | .2xiaobai |     | english   |

| NULL | NULL     | NULL      |  | .2xiaobai |     | physics   |

| NULL | NULL     | NULL      |  | 3xiaobai   |     | shuxue    |

| NULL | NULL     | NULL      |  | 123xiaohei |     | astronaut |

| NULL | NULL     | NULL      |  | .12xiaohei |     | english   |

+------+----------+-----------+----+------------+-------+-----------+

 rows in set (0.00 sec)