Detailed tutorial on installing MySQL offline on CentOS7

mariadb-libs-5.5.52-1.el7.x86_64
rpm -qa|grep mariadb
rpm -e --nodeps mariadb-libs

rpm -ivh mysql-community-common-5.7.21-1.el7.x86_64.rpm
 rpm -ivh mysql-community-libs-5.7.21-1.el7.x86_64.rpm 
rpm -ivh mysql-community-devel-5.7.21-1.el7.x86_64.rpm 
rpm -ivh mysql-community-libs-compat-5.7.21-1.el7.x86_64.rpm 
rpm -ivh mysql-community-client-5.7.21-1.el7.x86_64.rpm
 rpm -ivh mysql-community-server-5.7.21-1.el7.x86_64.rpm

# Disabling symbolic-links is recommended to prevent assorted security risks
skip-grant-tables #Add this sentence, then you don't need a password to log in to MySQL symbolic-links=0

mysql> set password for root@localhost = password('123456');
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement
mysql> flush privileges; #Update privileges Query OK, 0 rows affected (0.00 sec)
mysql> set password for root@localhost = password('123456'); 
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql>flush privileges; #Update privilegesmysql>quit; #Exitservice mysqld stop #Stop MySQL service and restore MySQL configurationvim /etc/my.cnf #Modify configuration file# Disabling symbolic-links is recommended to prevent assorted security risks
# skip-grant-tables # Comment out this sentence symbolic-links=0
service mysqld start # Start mysql service mysql -uroot -p # Enter new password to log in