You can use the ALTER DATABASE statement to change a database’s definition in one of the following ways:
By changing the name of the database.
By adding one or more new data files to the database. If you want, you can put these files in a user-defined filegroup. All files added in a single ALTER DATABASE statement must go in the same filegroup.
By adding one or more new log files to the database.
By removing a file or a filegroup from the database. You can do this only if the file or filegroup is completely empty. Removing a filegroup removes all the files in it.
By adding a new filegroup to a database. (Adding files to those filegroups must be done in a separate ALTER DATABASE statement.)
By modifying an existing file in one of ...