MySQL 5.7 installation and configuration tutorial under CentOS7 64 bit

Installation environment: CentOS7 64-bit MINI version, install MySQL5.7

1. Configure YUM source

Download the YUM source rpm installation package from the MySQL official website: http://dev.mysql.com/downloads/repo/yum/

# Download the mysql source installation package shell> wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
# Install mysql source shell> yum localinstall mysql57-community-release-el7-8.noarch.rpm

Check whether the mysql source is installed successfully

shell> yum repolist enabled | grep "mysql.*-community.*" 

The above picture shows that the installation is successful.

You can modify the yum source to change the default installed mysql version. For example, if you want to install version 5.7, just change enabled=0 of the 5.7 source to enabled=1. The effect after the modification is as follows:

vim /etc/yum.repos.d/mysql-community.repo 

2. Install MySQL

shell> yum install mysql-community-server

3. Start MySQL service

shell> systemctl start mysqld

Check the startup status of MySQL

4. Start the machine

shell> systemctl enable mysqld
shell> systemctl daemon-reload

5. Modify the root local login password. The root default password may be empty.

1. If the default password is empty, press Enter to log in directly

There is a password. After MySQL is installed, a default password is generated for root in the /var/log/mysqld.log file. Find the root default password in the following way, and then log in to mysql to modify it:

shell> grep 'temporary password' /var/log/mysqld.log
shell>mysql -uroot -p
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!'; 
Or mysql> set password for 'root'@'localhost'=password('MyNewPass4!');

Note: MySQL 5.7 has a password security check plug-in (validate_password) installed by default. The default password check policy requires that the password must contain uppercase and lowercase letters, numbers, and special symbols, and the length must not be less than 8 characters. Otherwise, the error message ERROR 1819 (HY000): Your password does not satisfy the current policy requirements will be displayed, as shown in the following figure:

You can view password policy information through the msyql environment variable:

mysql> show variables like '%password%'; 

validate_password_policy: Password policy, the default is MEDIUM policy
validate_password_dictionary_file: Password policy file, required only if the policy is STRONG
validate_password_length: minimum password length
validate_password_mixed_case_count: length of uppercase and lowercase characters, at least 1
validate_password_number_count: at least 1 number
validate_password_special_char_count: at least 1 special character

The above parameters are the password checking rules for the default policy MEDIUM.

There are the following password policies:

MySQL official website password policy detailed description: http://dev.mysql.com/doc/refman/5.7/en/validate-password-options-variables.html#sysvar_validate_password_policy

Modify Password Policy

Add validate_password_policy configuration in the /etc/my.cnf file to specify the password policy

# Select one of 0 (LOW), 1 (MEDIUM), 2 (STRONG). Selecting 2 requires providing a password dictionary file validate_password_policy=0

If you do not need a password policy, add the following configuration to the my.cnf file to disable it:

validate_password = off

Restart the MySQL service to make the configuration take effect:

systemctl restart mysqld

6. Add remote login user

By default, only the root account is allowed to log in locally. If you want to connect to MySQL on other machines, you must modify root to allow remote connections, or add an account that allows remote connections. For security reasons, I add a new account:

mysql> GRANT ALL PRIVILEGES ON *.* TO 'yangxin'@'%' IDENTIFIED BY 'Yangxin0917!' WITH GRANT OPTION;

7. Configure the default encoding to utf8

Modify the /etc/my.cnf configuration file and add the encoding configuration under [mysqld] as follows:

[mysqld]
character_set_server=utf8
init_connect='SET NAMES utf8'

Restart the mysql service and check the default database encoding as follows:

Default configuration file path:
Configuration file: /etc/my.cnf
Log file: /var/log//var/log/mysqld.log
Service startup script: /usr/lib/systemd/system/mysqld.service
Socket file: /var/run/mysqld/mysqld.pid

Uninstall mysql on Centos7

View the current installation status

rpm -qa|grep -i mysql 

yum remove mysql 

rpm -e mysql-community-release-el7-5.noarch

If a dependency error is prompted

Then execute

rpm -ev --nodeps mysql-community-libs-5.6.43-2.el7.x86_64 

Delete in this way

Then find the directory of the old version of mysql and delete the files and libraries of the old version of mysql. I did not delete the old library and directly did an upgrade installation.

find / -name mysql

Delete the corresponding mysql directory

rm -rf /var/lib/mysql 

Note: /etc/my.cnf will not be deleted after uninstallation and needs to be deleted manually

rm -rf /etc/my.cnf

Sometimes my.cnf is not necessarily in /etc, you can use the command to find it

find / -name my.cnf

Check again whether mysql is installed on the machine

rpm -qa|grep -i mysql

I did not delete the original configuration files and database, but directly installed 5.7 and the original database. However, the database could not be used, so I used two commands to solve the problem.

set @@global.show_compatibility_56=ON; 

The original database can be used normally.

Summarize

The above is the installation and configuration tutorial of MySQL5.7 under CentOS7 64-bit introduced by the editor. I hope it will be helpful to everyone. If you have any questions, please leave me a message and the editor will reply to you in time. I would also like to thank everyone for their support of the 123WORDPRESS.COM website!
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