here is a you tube video for backing a database using hedi SQL that I found through a google search for:
heidisql backup database
https://www.youtube.com/watch?v=5GJkGUWvv8c
here are some tutorial i found using a google search for:
phpmyadmin import export database
https://www.youtube.com/watch?v=NnOE0KWHGkY
these should help answer your questions.