Minor issues with using mysql in linux

Just migrated a project to the newly installed linux system, because mysql is used to install it:

Yum install mysql

Yum install mysql-server

Then start the mysql service:

Service mysqd start

At this time, you can log on, but the root user should have no password, which is not secure, so set the password:

Mysqladmin password '200'

Then, you cannot log on... No matter whether you enter the password 123 or not, you cannot log on... Thank you for your answers.

I can only stop the service first, and then reset the password. The second step is to enter mysql in special mode, not long term:

Service mysqld stop
Mysqld_safe -- skip-grant-tables &

Okay, you can go:

Mysql-uroot-p

Select database:

Use mysql;

Set password:
Update user set password = PASSWORD ("newpass") where user = "root ";
Update permission:
Flush privileges;
Exit:

Quit

Restart the mysql service:
Service mysqld restart
Enter the new password:
Mysql-uroot-p