| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.flink.table.examples.scala |
| |
| import org.apache.flink.api.scala._ |
| import org.apache.flink.streaming.api.scala.{DataStream, StreamExecutionEnvironment} |
| import org.apache.flink.table.api.TableEnvironment |
| import org.apache.flink.table.api.scala._ |
| |
| /** |
| * Simple example for demonstrating the use of SQL on a Stream Table. |
| * |
| * This example shows how to: |
| * - Convert DataStreams to Tables |
| * - Register a Table under a name |
| * - Run a StreamSQL query on the registered Table |
| * |
| */ |
| object StreamSQLExample { |
| |
| // ************************************************************************* |
| // PROGRAM |
| // ************************************************************************* |
| |
| def main(args: Array[String]): Unit = { |
| |
| // set up execution environment |
| val env = StreamExecutionEnvironment.getExecutionEnvironment |
| val tEnv = TableEnvironment.getTableEnvironment(env) |
| |
| val orderA: DataStream[Order] = env.fromCollection(Seq( |
| Order(1L, "beer", 3), |
| Order(1L, "diaper", 4), |
| Order(3L, "rubber", 2))) |
| |
| val orderB: DataStream[Order] = env.fromCollection(Seq( |
| Order(2L, "pen", 3), |
| Order(2L, "rubber", 3), |
| Order(4L, "beer", 1))) |
| |
| // register the DataStreams under the name "OrderA" and "OrderB" |
| tEnv.registerDataStream("OrderA", orderA, 'user, 'product, 'amount) |
| tEnv.registerDataStream("OrderB", orderB, 'user, 'product, 'amount) |
| |
| // union the two tables |
| val result = tEnv.sqlQuery( |
| "SELECT * FROM OrderA WHERE amount > 2 UNION ALL " + |
| "SELECT * FROM OrderB WHERE amount < 2") |
| |
| result.toAppendStream[Order].print() |
| |
| env.execute() |
| } |
| |
| // ************************************************************************* |
| // USER DATA TYPES |
| // ************************************************************************* |
| |
| case class Order(user: Long, product: String, amount: Int) |
| |
| } |