Create MySQL DB, User & Grant Permission

create database

mysql> create database mydb
       DEFAULT CHARACTER SET utf8
       DEFAULT COLLATE utf8_general_ci;
       

create user/grant rights

mysql> GRANT ALL PRIVILEGES ON ${db_name}.* TO db-user@$localhost IDENTIFIED BY 's3cret!';
       FLUSH PRIVILEGES;

that's all
you can also use the script below, i found it in WeBacula Project, nice tiny thing :)

#/bin/bash
bindir="/usr/bin"
db_name="mydb"

db_user="dbuser"
db_password="s3cret!"
host="localhost"

if $bindir/mysql $* -f <<END-OF-DATA
CREATE DATABASE ${db_name}
        DEFAULT CHARACTER SET utf8
        DEFAULT COLLATE utf8_general_ci;

GRANT ALL PRIVILEGES ON ${db_name}.* TO ${db_user}@${host} IDENTIFIED BY '${db_password}';
FLUSH PRIVILEGES;
END-OF-DATA
then
   echo "Creation of ${db_name} database succeeded."
else
   echo "Creation of ${db_name} database failed."
fi
exit 0