Try to log in to port 3308
[root@lzl mysql]# mysql -P 3308 -uroot -poracle
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 23
Server version: 5.7.20 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
mysql> show variables like '%port%';
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| innodb_support_xa | ON |
| large_files_support | ON |
| port | 3306 |
| report_host | |
| report_password | |
| report_port | 3306 |
| report_user | |
| require_secure_transport | OFF |
+--------------------------+-------+
8 rows in set (0.15 sec)
It seems to be logged in, but I log in and find that the port is 3306
It feels very strange, --help checked -P is indeed the designated port
Add a space to try
[root@lzl mysql]# mysql -uroot -poracle -P 3308
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 25
Server version: 5.7.20 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show variables like '%port%';
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| innodb_support_xa | ON |
| large_files_support | ON |
| port | 3306 |
| report_host | |
| report_password | |
| report_port | 3306 |
| report_user | |
| require_secure_transport | OFF |
+--------------------------+-------+
8 rows in set (0.00 sec)
Still 3306
Later, I thought that it might be a socket problem, so I specified socket login
[root@lzl mysql]# mysql -uroot -poracle -P 3308 -S/tmp/mysql3308.sock
mysql> show variables like '%port%';
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| innodb_support_xa | ON |
| large_files_support | ON |
| port | 3308 |
| report_host | |
| report_password | |
| report_port | 3308 |
| report_user | |
| require_secure_transport | OFF |
+--------------------------+-------+
8 rows in set (0.00 sec)
Successful landing! ! !
Try not to specify the port, only the socket
[root@lzl mysql]# mysql -uroot -p -S/tmp/mysql3308.sock
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.20 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show variables like '%port%';
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| innodb_support_xa | ON |
| large_files_support | ON |
| port | 3308 |
| report_host | |
| report_password | |
| report_port | 3308 |
| report_user | |
| require_secure_transport | OFF |
+--------------------------+-------+
8 rows in set (0.00 sec)
mysql>
Can also
Question: Why do I log in to 3306 when my -P specifies port 3308?
When I specified -P3308, mysql went to find the default socket /tmp/mysql.sock. This socket was my 3306, so I logged in to 3306.
to sum up:
1. There are two ways to log in to mysql, socket and tcp/ip.
2. Sockets are generally used for local login, sockets are local files, and each mysql instance has a socket. For example, if mysql -uroot -poracle is not specified, the file /tmp/mysql.sock is used by default. As long as you don't specify -h, you will log in using socket
3. There is also a method of tcp/ip, which is generally used for remote login. As long as -h host is specified, mysql will use tcpip to log in to the database. Even if the machine specifies -h, it is also tcp/ip login
So I did some experiments:
if you log in remotely, you should specify -P port directly, no need to specify socket
[root@lzl ~]# mysql -h192.168.43.6 -P3308 -uroot -poracle
mysql: [ Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with; or \g.
Your MySQL connection id is 4
Server version: 5.7.20 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show variables like '%port%';
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| innodb_support_xa | ON |
| large_files_support | ON |
| port | 3308 |
| report_host | |
| report_password | |
| report_port | 3308 |
| report_user | |
| require_secure_transport | OFF |
+--------------------------+-------+
8 rows in set (0.06 sec)
mysql>
So, there are now 2 ways to log in to the 3308 port database
mysql -hlocalhost -P3308 -uroot -poracle
mysql -S/tmp/mysql3308.sock -uroot -poracle