How to create users and manage permissions in MySQL

mysql> use mysql
Database changed

# Specify the IP address: 192.118.1.1 as user chao to log in create user 'chao'@'192.118.1.1' identified by '123';
#Specify the IP address: 192.118.1. Chao user login create user 'chao'@'192.118.1.%' identified by '123';
# Specify any ip user chao to log in create user 'chao'@'%' identified by '123';

drop user 'username'@'IP address';

rename user 'username'@'IP address' to 'new username'@'IP address';

set password for 'user name'@'IP address'=Password('new password');

#View permissions show grants for 'user'@'IP address'

#Authorize user chao to query, insert, and update only the db1.t1 file grant select ,insert,update on db1.t1 to "chao"@'%';

#Authorize the Chao user to query only the db1 file grant select on db1.* to "chao"@'%';

# Indicates all permissions, except for the grant command, which is only available to root. User chao has any operation on the t1 file under db1. grant all privileges on db1.t1 to "chao"@'%';
#The chao user can perform any operation on the files in the db1 database. grant all privileges on db1.* to "chao"@'%';
#chao user has any operation on all files in the database grant all privileges on *.* to "chao"@'%';

#Revoke permissions #Revoke any operation of user Chao on the t1 file of db1 revoke all on db1.t1 from 'chao'@"%"; 

# Revoke all permissions of the Chao user from the remote server on all tables in database db1 revoke all on db1.* from 'chao'@"%"; 

Revoke all privileges on *.* from 'chao'@'%';