mysql 5.7新建用户

# mysql -uroot -p
mysql> set global validate_password_policy=0;  
mysql> set global validate_password_length=4;  

mysql> create database DbName character set utf8mb4;
mysql> create user 'UserName'@'%' identified by 'UserPasswd';

mysql> grant all privileges on DbName.* to UserName@'%' identified by 'UserPasswd';
mysql> exit

# mysql -uUserName -pUserPasswd
mysql> show databases;