Installing mysql5.7 on linux (CentOs7)

Keywords: Linux Database MySQL

mysql installation

  1. Uninstall the original mysql
#Check whether there is a built-in mariadb
rpm -qa | grep -i mariadb

#If yes, uninstall the built-in mariadb
rpm -e --nodeps mariadb-libs
  1. Modify / tmp directory permissions
chmod -R 777 /tmp
  1. Check for dependencies
#The current package should exist [there are many virtual machines under normal circumstances]
rpm -qa|grep libaio

#Current package should exist
rpm -qa|grep net-tools
  1. Install the four rpm installation packages. The installation sequence must be as follows [I am currently installing in the / opt directory]
rpm -ivh mysql-community-common-5.7.28-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-5.7.28-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-5.7.28-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-5.7.28-1.el7.x86_64.rpm

5. View mysql version

mysqladmin --version

  1. Execute the rpm -qa|grep -i mysql command to check whether the installation is successful. You need to add - i without case sensitivity, otherwise you can't find it.

    Directory structure after installation
--basedir	/usr/bin	Related command directory	mysqladmin mysqldump Such command
--datadir	/var/lib/mysql/	mysql Storage path of database file	
--plugin-dir	/usr/lib64/mysql/plugin	mysql Plug in storage path	
--log-error	/var/log/mysqld.log	mysql Error log path	
--pid-file	/var/run/mysqld/	process pid file	
--socket	/var/lib/mysql/mysql.sock	For local connection unix s socket 	
	/usr/share/mysql	Profile directory	mysql Scripts and configuration files
	/etc/systemd/system/	Scripts related to service startup and shutdown	
	/etc/my.cnf	mysql configuration file	cat /etc/my.cnf

Service initialization

In order to ensure that the database directory and file owner are mysql login users, if you are running mysql service as root, you need to execute the following command to initialize:

mysqld --initialize --user=mysql 

In addition, the -- initialize option is initialized in the "safe" mode by default. A password will be generated for the root user and marked as expired. You need to set a new password after logging in

View password: cat /var/log/mysqld.log

Sometimes when viewing the log, an error will be reported [there is no screenshot of the error, sorry]: delete the initialized data and reinitialize

rm -rf /var/lib/mysql/*

Now check whether the mysql service is started. The following commands can be viewed by yourself
Start: systemctl start mysqld.service
Close: systemctl stop mysqld.service
Restart: systemctl restart mysqld.service
View status: systemctl status mysqld.service
View process: ps -ef | grep -i mysql
Check whether the service starts automatically: systemctl is enabled mysqld.service
Set service self startup: systemctl enable mysqld.service

Log in to mysql according to the temporary password. If you are currently logged in to mysql, please check whether the service is started

Enter the following command and press enter: mysql -u root -p

Enter temporary password

Change temporary password

#The root user sets the password to root
ALTER USER 'root'@'localhost' IDENTIFIED BY 'root';

Change the default character set for databases and data tables

First, take a look at the default character set of the database and data table

show variables like 'character%';

| Variable_name | Value |
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
I have changed the default encoding of the database and data table
Modify character set: vim /etc/my.cnf

After modification, please restart mysql: systemctl restart mysqld

Then you can operate happily. If you don't understand, you can comment and ask me. Thank you

Posted by drumhrd on Sun, 10 Oct 2021 19:41:45 -0700