How can I run sql commands from a file or import tables from the mysqldump?

There are two options for running sql commands from a file:

1.  All command line:

mysql -u [username] -h [hostname] -p [database] < [filename.sql]

2.  From the mysql command line:

mysql> source [filename.sql]

The second is helpful when you want to execute a few commands prior to loading in the file, such as selecting the database, setting some mysql options, etc.