1.download mysql from mysql website.it’s a dmg file, open the dmg file 4 files in it.install the pkg file and the prefPane file

2.to use mysql command in the terminal,modify the /etc/bashrc file

#mysql
alias mysql='/usr/local/mysql/bin/mysql'
alias mysqladmin='/usr/local/mysql/bin/mysqladmin'

add in the end of bashrc file.

3.reopen the terminal,try use mysql command.

4.use mysqladmin to set root user

mysqladmin -u root password mysqlpassword