The installation of mysql under centos7 and the installation of mysql under linux are different

Today, mysql was installed for a day, and finally installed after get off work at night. There have been various errors.
The reason why the error has been reported is actually because centos7 is only a series of linux, and linux is a large category. I searched for the method of installing mysql through linux, and found a lot of installation methods that are not suitable for me, mainly to report this error

Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

In fact, when I saw this error, mysql has been installed, but it was caused by an access permission problem.
Just execute:

chown -R mysql:mysql /var/lib/mysql

Then restart is ok.
The specific installation process is as follows
1, download the yum source

wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm

2.安装
sudo rpm -ivh mysql-community-release-el7-5.noarch.rpm

After this step is performed, the installation is actually completed. If you encounter the above permission problem, you can install my solution to solve it.