org.apache.flink.table.examples.java.basics

Class UpdatingTopCityExample

java.lang.Object

org.apache.flink.table.examples.java.basics.UpdatingTopCityExample

public final class UpdatingTopCityExample
extends Object

Example for aggregating and ranking data using Flink SQL on updating tables.

The example shows how to declare a table using SQL DDL for reading bounded, insert-only data and how to handle updating results in streaming mode. It should give a first impression about Flink SQL as a changelog processor. The example uses some streaming operations that produce a stream of updates. See the other examples for pure CDC processing and more complex operations.

In particular, the example shows how to

• setup a TableEnvironment,
• use the environment for creating a CSV file with bounded example data,
• aggregate the incoming INSERT changes in an updating table,
• compute an updating top-N result,
• collect and materialize the table locally.

The example executes two Flink jobs. The results are written to stdout.

Note: Make sure to include the SQL CSV format when submitting this example to Flink (e.g. via command line). This step is not necessary when executing the example in an IDE.

Constructor Summary

Constructors

Constructor and Description
UpdatingTopCityExample()

Method Summary

Modifier and Type	Method and Description
static void	main(String[] args)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UpdatingTopCityExample

public UpdatingTopCityExample()

Method Detail

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception