DataStax-Examples/quickstart-java

A basic CRUD Java application using the DataStax Java Driver for Apache Cassandra. Run the GettingStartedComplete.java file if you want to skip the exercise and run the application with the complete code.Contributors: Rebecca MillsObjectivesTo demonstrate how to perform basic CRUD operations with the DataStax Java Driver.The intent is to help users get up and running quickly with the driver.How this Sample WorksThis project walks through basic CRUD operations using Cassandra. The demo application will first insert a row of user data, select that same row back out, update the row and finally delete the user. The README includes the code snippets to be filled in to the main application code to complete the functionality.PrerequisitesA running instance of Apache Cassandra® 2.1+Maven build automation toolJava 8Project LayoutGettingStarted.java - Main application file with space to fill in CRUD operation codeusers.cql - Use this file to create the schemaCreate the keyspace and tableThe resources/users.cql file provides the schema used for this project:CREATE KEYSPACE demo WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '1'};CREATE TABLE demo.users ( lastname text PRIMARY KEY, age int, city text, email text, firstname text);Connect to your clusterAll of our code is contained in the GettingStarted class.Note how the main method creates a session to connect to our cluster and runs the CRUD operations against it.Replace the default parameters in CqlSession.builder() with your own hostname, port and datacenter.// TO DO: Fill in your own host, port, and data centertry (CqlSession session = CqlSession.builder() .addContactPoint(new InetSocketAddress("127.0.0.1", 9042)) .withKeyspace("demo") .withLocalDatacenter("datacenter1") .build()) CRUD OperationsFill the code in the methods that will add a user, get a user, update a user and delete a user from the table with the driver.INSERT a userprivate static void setUser(CqlSession session, String lastname, int age, String city, String email, String firstname) { //TO DO: execute SimpleStatement that inserts one user into the table session.execute( SimpleStatement.builder( "INSERT INTO users (lastname, age, city, email, firstname) VALUES (?,?,?,?,?)") .addPositionalValues(lastname, age, city, email, firstname) .build());}SELECT a userprivate static void getUser(CqlSession session, String lastname) { //TO DO: execute SimpleStatement that retrieves one user from the table //TO DO: print firstname and age of user ResultSet rs = session.execute( SimpleStatement.builder("SELECT * FROM users WHERE lastname=?") .addPositionalValue(lastname) .build()); Row row = rs.one(); System.out.format("%s %d\n", row.getString("firstname"), row.getInt("age"));}UPDATE a user's ageprivate static void updateUser(CqlSession session, int age, String lastname) { //TO DO: execute SimpleStatement that updates the age of one user session.execute( SimpleStatement.builder("UPDATE users SET age =? WHERE lastname =? ") .addPositionalValues(age, lastname) .build());}DELETE a userprivate static void deleteUser(CqlSession session, String lastname) { //TO DO: execute SimpleStatement that deletes one user from the table session.execute( SimpleStatement.builder("DELETE FROM users WHERE lastname=?") .addPositionalValue(lastname) .build());}