In most cases, you access databases from the file system. However, it is also possible to access databases from the classpath. The databases can be archived into a jar or zip file or left as is.
All such databases are read-only.
To access an unarchived database from the classpath, specify the name of the database relative to the directory in the classpath. You can use the classpath subprotocol if such a database is ambiguous within the directory system.
For example, for a database called sample in C:\derby\demo\databases, you can put the C:\derby\demo\databases directory in the classpath and access sample like this:
jdbc:derby:/sample
The forward slash is required before sample to indicate that it is relative to C:\derby\demo\databases directory.
If only C:\derby were in the class path, you could access sample (read-only) like this:
jdbc:derby:/demo/databases/sample