Does a database backup include all files?

Question

If I have two files in my database (mdf & ndf), when I do a backup of the database with the statement:

backup database mydb;

are both the two files are backed up?

Answer 1

Yes. Details here: Backup Overview (SQL Server)

This is the section relevant for you:

• Full backup

  A full backup contains all the data in a specific database or set of filegroups or files, and also enough log to allow for recovering that data.

You should always test the backup (ideally by performing a restore to another location) to ensure you can recover your data in the event of a disaster.