boot2docker - How to import a database into a Docker container using docker-compose -

i working official wordpress docker image docker-compose on mac (using boot2docker). need one-off data import. i'm not sure how this. how can import data database container?

wordpress:   image: wordpress   links:     - db:mysql   ports:     - 8080:80   volumes:     - .:/var/www/html/wp-content/themes/my-theme-name  db:   image: mariadb   environment:     mysql_root_password: example 

when using official wordpress image, default name of created database wordpress.

so after have deployed wordpress application docker-compose, can import wordpress database by

docker exec -i db mysql -uroot -pexample wordpress < dump.sql