What to do if you forget the root password of Mysql5.7 (simple and effective method)

# The simplest and most brutal way is to find the mysql configuration file and edit it directly with vim /etc/my.cnf
 # Add a line in [mysqld] to skip the permission restriction skip-grant-tables
# Save and exit to restart the mysql service service mysqld restart
# User login mysql -uroot -p (click Enter directly, the password is empty)
# Select database use mysql;
# But the password field does not exist in version 5.7, so we need to use the following modification to reset the password update user set authentication_string=password('new password') where user='root';
#Flush privileges;
# Exit mysql
quit;
# Delete skip-grant-tables in the configuration file my.cnf that was modified at the beginning and restart mysql
service mysqld restart
# After you log in to MySQL, you will find that when you execute the command, ERROR 1820 (HY000) will appear: You must reset your password using ALTER USER statement;
# This is a reminder that you need to change the password when you execute SET PASSWORD = PASSWORD('root');
# If ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
# You need to execute two parameters to cancel the default password strength of MySQL. Of course, you can also increase the complexity of your password. set global validate_password_policy=0; 
set global validate_password_mixed_case_count=2;
# Now you can execute it again and it will be ok SET PASSWORD = PASSWORD('root');
# Let's talk about the character set problem in MySQL show variables like "%character%";
# The following situations can be ignored...
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
#Find the mysql configuration file and add a few words to it. Add character-set-server=utf8 under mysqld
collation-server=utf8_general_ci
# Add default-character-set=utf8 under client