How do i run mysql command from a terminal?

I have the following sql command which i usually run in phpmyadmin by selecting the database then running it in the command window

DELETE FROM `wp_posts` WHERE `post_type` = "attachment"

However i've never done this via terminal before. What would be the easiest way to point a command to a specific database and run it?

To run it from the terminal you must first be logged into mysql and then start the program The ideal code would be

mysql -u(username) -p(password) (the name of the database) -e "DELETE FROM `wp_posts` WHERE `post_type` = "attachment""

I`m sure this works, hope it helps