CentOS7下在线安装mysql

yum update

wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm
sudo rpm -ivh mysql-community-release-el7-5.noarch.rpm
yum update

yum install mysql-server
systemctl start mysqld 

mysql_secure_installation
提示输入root密码，初始为null，回车就可以设置root密码了
之后提示一连串的问题,根据需要自己选择y 或者 n吧

mysql -uroot -p

mysql>show variables like '%character%'; 
可以看到database和server编码都为latin1，我们修改为utf8

default-character-set = utf8

character_set_server =  utf8

systemctl restart  mysql.service

mysql -uroot –proot
mysql>show variables like '%character%';