Drupal - How to Make a Backup Copy of MySQL Database
Here is how you can make a backup copy of your Drupal's MySQL database from a terminal:
mysqldump -u my_drupal_mysql_uer_name -p my_drupal_mysql_database_name > ~/my_drupal_sql_dump.sql
I like to clear all of Drupal's caches before running the dump so there isn't a bunch of cache data in the export.
If you'd prefer to use Drush, check out this article instead: Use Drush to Export/Import a Drupal MySQL Database Dump File