Centos Tutorial for Installing MYSQL8.X

Installation of MySQL (4, 5, 6 can be omitted)

Statement: CentOS version 7.6, installed MySQL version 8.0. 17

1. First, uninstall the mysql correlation, including MariaDB.

rpm -pa | grep mysql # Use the search results `rm -rf  Filename `  Delete it, skip it if you don't have it 
rpm -pa | grep mariadb # Use the search results `rm -rf  Filename `  Delete it, skip it if you don't have it 
find / -name mysql # Find and delete related folders, skip if not (ibid.) 
find / -name mariadb # Find and delete related folders, skip if not (ibid.) 

2. Back up the default repo source of centOS, and download the repo source of Alibaba Cloud or Netease to replace the default source.

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

cd /etc/yum.repos.d/
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

3. Clean up the yum and create the yum cache.

sudo yum clean all
sudo yum makecache

4. View the content of mysql in the software source repository

yum repolist | grep mysql

5. Check whether the corresponding version of mysql is enabled

cat /etc/yum.repos.d/mysql-community

6. Set the version that needs to be installed to enable (I installed mysql Community Version 8.0 here)

yum-config-manager --enable mysql80-comminity

7. Perform the installation

yum install mysql-community-server.x86_64

8. Check the running status of mysql, which is not started by default after installation

#  View MySQL Service running status, active Indicates that it has been started, inactive Indicates that it is not started, failed Indicates startup failure 
systemctl status mysqld.service
#  Start MySQL Services 
systemctl start mysqld.service
#  Stop MySQL Services 
systemctl stop mysqld.service
#  Restart MySQL Services 
systemctl restart mysqld.service

9. View the initial password

The new version of mysql just installed automatically generates a temporary password, which is saved in ` /etc/log/mysqld. log '

cat /var/log/mysqld.log | grep "password"

10. Log in with your initial password

Copy the password of step 1, enter ` mysql-uroot-p password ', or press Enter without entering the password first, and paste the password at the prompt place (the password is not displayed, just paste it once).

11. Change the initial password

show databases;
use mysql;
#  If you change your password to  NewPassword!  Include upper and lower case alphanumeric symbols as much as possible for safety 
alter 'user'@'localhost' identified by 'NewPassword!'; 

12. Modify access permissions so that they can connect remotely

update user set Host='%' where User='root' and Host='localhost';

13. Refresh permissions

flush privileges;

14. Create a new user

create user  User name  identified by ' Password '; 
#  For example, creating a user specifies the hosts that can be accessed, and specifies the database tables that can be accessed and the corresponding permissions 
create user  User name @' Hostname ' identified by ' Password ';
grant select, update, create, delete on  Database name . Table name  to  User name ;

15. Give permissions, remember to refresh permissions before they take effect

grant select on database name. Table name to user; # All permissions can use all

flush privileges;

MySQL Backup

Backup: Datasheet Structure + Data

mysqdump -u root db1 > db1.sql -p;

Backup: Data table structure

mysqdump -u root -d db1 > db1.sql -p;

Import existing data into a database

Create a new database first

create database db10;

Import existing database files into db10 database

mysqdump -u root -d db10 < db1.sql -p;

= = Note = =

= = If the database reports an error: = =

= = "Job for mysqld. service failed because the control exited with error code. See" systemctl status mysqld. service "journalctl-xe" for details. "= =

Solution:

Database initialization:

rm -rf /var/log/mysql.log
rm -rf /var/ib/mysql

Summarize