public class Main {

    public static void main(String[] args) throws SQLException {
    final String driver="org.apache.derby.jdbc.EmbeddedDriver";
    final String url="jdbc:derby:db/testdb";

    try {
        Class.forName(driver);
        Connection connection=DriverManager.getConnection(url);

        //connection.createStatement().execute("create table channels(channel varchar(20),topic varchar(20))");
    //  connection.createStatement().execute("insert into channels (channel,topic) values('hbo','action')");
    //  System.out.println("saved");
        PreparedStatement preStmt=connection.prepareStatement("select * from channels");
        ResultSet set=null;
        set=preStmt.executeQuery();

        while(set.next()){


            System.out.print(set.getString(1));
            System.out.println(set.getString(2));

        }

    } catch (ClassNotFoundException e) {

        e.printStackTrace();
    }

    }

Exception in thread "main" SQL Exception: Database 'db/testdb' not found.
        at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source)
        at org.apache.derby.impl.jdbc.Util.newEmbedSQLException(Unknown Source)
        at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Sourc

cd D:Projectderbydb
set JAVA_HOME=C:/Program Files/Java/jdk1.8.0_92
set DERBY_HOME=C:/Program Files/Java/jdk1.8.0_92/db
set PATH=%PATH%;%DERBY_HOME%/bin

D:Projectderbydb>ij
ij version 10.11
ij> CONNECT 'jdbc:derby:testdb;create=true';

ij> CREATE TABLE cart (
      item VARCHAR(50),
      price DECIMAL (10,5),
      dt TIMESTAMP,
      primary key (item)
    );
ij> select * from cart;

C:Usersoraclesoon>ij
ij version 10.11
ij> CONNECT 'jdbc:derby:D:\Project\derbydb\testdb';
ij> select * from cart;