Detailed tutorial on installing MySQL database in Linux environment

1. Install the database

1) yum -y install mysql-server (simple)

The yum command automatically searches for MySQL service resources on the Internet, downloads them to the local computer, and completes the installation.

2) You can also download the MySQL service online, transfer it to the Linux system via xftp, and install it yourself (usually in the usr or opt directory)

2. Start the database

After the installation is complete, execute the command service mysqld start

3. Log in to the database

mysql -u root -p Press Enter and enter the password (the default user of mysql is root and the password is empty)

4. Use a database

After successful login, switch to MySQL database and enter: use mysql— There are 3 databases by default under MySQL service. To operate a table in a database, enter it with use first.

5. Connect to the database : Use Navicat for MySQL to connect to the database

1) Query all users who can log in and hosts that support links from the user table:

select user,host,password from user; (mysql statements all end with a semicolon)

2) The difference between the value of the host field in the user table being % or localhost

host=%, means all IPs have connection permission

3) Create a new root user and grant this user the operation permissions for all databases and all objects. The % in this authorization statement means that any host can connect to the MySQL server. In this case, there will be no problem using the Navicat client. The authorization statement is: grant all privileges on *.* to 'root'@'%' identified by '123456' with grant option;

all privileges: all permissions—add, delete, modify, and query

*.* (database name. table name): * before . means all databases, * after . means all tables, *.* means all tables in all databases under MySQL service

Eg: mysql.user—user table under mysql database

flush privileges;—refresh privileges

4) If the internal server cannot be connected, turn off the firewall and exit mysql first (exit or Ctrl+C)

If the cloud server cannot be connected, open port 3306 (MySQL default port) in the cloud server security component.

6. Steps to uninstall mysql

1) Uninstall mysql installed by yum (only applicable to mysql installed by yum command)

yum -y remove mysql*

2) Find the mysql installation file

find / -name mysql

3) Use rm-rf to delete the found mysql files

4)Start/Stop/Status of MySQL Service

service mysqld start/stop/status

If there are multiple MySQL services on a server, modify the default port number in the /etc/my.cnf file

7. Supplementary content - knowledge points on internal and external networks

1) Differences between internal and external networks

Intranet is also called LAN or private network, which can only be accessed by users in a single LAN.

Eg: ping the intranet IP 192.168.88.133

The external network is also called the wide area network or public network. It is an IP address that can be accessed by all users on the Internet.

Eg: ping public network IP 106.52.90.235

2) The local computer needs to access the test environment and ensure that it is in the same LAN, that is, in the same IP network segment (the red part of 192.168.88.133)

8. Supplementary content - common network knowledge points

1) The difference between TCP and UDP:

TCP is a reliable transmission protocol because it needs to establish a connection to transmit data, while UDP is not

2) TCP establishes a connection and shakes hands 3 times, and disconnects the connection and waves 4 times

Connection handshake 3 times: A and B send and receive functions normally

üFirst time: A→B sends a message, B receives the message (B knows: B received the message OK, A sent the message OK)

ü Second time: B→A sends a message, A receives the message (A knows: B sent OK, A sent and received OK)

ü The third time: A→B sends a message, and B receives the message (B knows: B sent OK)

Disconnect: wave 4 times

üFirst time: A→B, tell B that data sending is complete and the connection needs to be disconnected

ü The second time: B→A, let A wait until B receives the data

üThird time: B→A, data transfer is complete, you can disconnect

ü The fourth time: A→B, the connection will be disconnected after XX seconds

Summarize

This is the end of this detailed tutorial on how to install MySQL database in Linux environment. For more information about installing MySQL in Linux environment, please search for previous articles on 123WORDPRESS.COM or continue to browse the following related articles. I hope you will support 123WORDPRESS.COM in the future!