Using Derby with IDEs When you use an integrated development environment (IDE) to develop an embedded application, you might need to run within a server framework. IDEsusing Derby withand need to use server framework

This is because an IDE might try connecting to the database from two different JVMs, whereas only a single JVM instance should connect to a database at one time (multiple connections from the same JVM are allowed).

An "embedded application" is one which runs in the same JVM as the application. Such an application uses the embedded driver (org.apache.derby.jdbc.EmbeddedDriver) and connection URL (jdbc:derby:databaseName). If you use this driver name or connection URL from the IDE, when the IDE tries to open a second connection to the same database with the embedded , the attempt fails. Two JVMs cannot connect to the same database in embedded mode.