How to modify the root user name in centos:
1. Replace root with the username you want to modify in /etc/passwd, then save and exit;
2. Replace root with the user name you want to modify in /etc/shadow, then save and exit;
the method to modify the MYSQL user name:
After MySQL 5.7, the password field has been deleted from the mysql.user table, and the new field name is "authenticalion_string"
use mysql;
So the method to modify the user name in mysql is as follows:
update user set authentication_string=password("Asat123@") where user="cdzx" and Host="localhost";
refresh command: flush privileges;
The method to modify the root user name
update user set user="newName" where user="root";
flush privileges;
Finally, modify the method of displaying your user name when logging in:
add the following to the /etc/profile file:
Command to display user information: export PS1='[\u@\h\w]'
Finally use the command to make it effective: source /etc/profile command.