Working with multiple databases?

Using sqlite3 on Linux, how can one work with multiple databases?

I'd like to do something like the following in database 1?

sqlite3 database1.db
insert into database1.mytable values (select * from database2.mytable)

How do I write the SELECT query for database2 above?

(reposting swasheck's comment as reply)

sqlite3 database1.db
> ATTACH DATABASE 'database2.db' AS database2;
> INSERT INTO mytable SELECT * FROM database2.mytable;

StackExchange Database Administrators Q#25127, answer score: 14