Apache Derby is a lightweight, open-source database management system that can be used with Java. Derby can be used in two modes - embedded mode and network client-server mode. In this guide, we will discuss how to use Derby in network client-server mode.

Here are the steps to work with Derby in network client-server mode:

1. Download and install Derby on the server machine. You can download Derby from the official Apache Derby website. Once you have downloaded the Derby distribution, extract it to a directory of your choice.

2. Start the Derby Network Server. To start the Derby Network Server, go to the directory where you extracted the Derby distribution and run the following command:

java -jar derbynet.jar start

This will start the Derby Network Server on port 1527.

3. Create a database on the server. You can use the Derby ij tool to create a database. To start the ij tool, run the following command:

java -jar derbyrun.jar ij

Once the tool starts, you can create a database by running the following command:

ij> connect 'jdbc:derby://localhost:1527/mydatabase;create=true';

This will create a database named "mydatabase" on the server.

4. Create a Java program that connects to the Derby Network Server. In your Java program, you will need to use the JDBC driver to connect to the Derby Network Server. Here is an example of how to create a connection to the server:

String url = "jdbc:derby://localhost:1527/mydatabase";
String username = "myusername";
String password = "mypassword";

Connection connection = DriverManager.getConnection(url, username, password);

Replace "myusername" and "mypassword" with the appropriate username and password for your database.

5. Use the connection to interact with the database. Once you have a connection to the Derby Network Server, you can use it to execute SQL statements and interact with the database. Here is an example of how to create a table:

Statement statement = connection.createStatement();
String sql = "CREATE TABLE mytable (id INT PRIMARY KEY, name VARCHAR(50))";
statement.executeUpdate(sql);

You can execute other SQL statements in a similar way.

6. Close the connection. Once you are finished using the connection, you should close it to free up system resources:

connection.close();

That's it! With these steps, you can use Derby in network client-server mode to create and interact with a database from your Java program.