| /* |
| * 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.nemo.examples.beam; |
| |
| import org.apache.beam.sdk.Pipeline; |
| import org.apache.beam.sdk.coders.RowCoder; |
| import org.apache.beam.sdk.extensions.sql.SqlTransform; |
| import org.apache.beam.sdk.options.PipelineOptions; |
| import org.apache.beam.sdk.schemas.Schema; |
| import org.apache.beam.sdk.transforms.Create; |
| import org.apache.beam.sdk.transforms.MapElements; |
| import org.apache.beam.sdk.transforms.SimpleFunction; |
| import org.apache.beam.sdk.values.*; |
| |
| import java.util.List; |
| import java.util.stream.Collectors; |
| import java.util.stream.IntStream; |
| |
| /** |
| * A simple SQL application. |
| * (Copied/Refined from the example code in the Beam repository) |
| */ |
| public final class SimpleSumSQL { |
| /** |
| * Private Constructor. |
| */ |
| private SimpleSumSQL() { |
| } |
| |
| /** |
| * @param args arguments. |
| */ |
| public static void main(final String[] args) { |
| final String outputFilePath = args[0]; |
| |
| final PipelineOptions options = NemoPipelineOptionsFactory.create(); |
| options.setJobName("SimpleSumSQL"); |
| final Pipeline p = Pipeline.create(options); |
| |
| // define the input row format |
| final Schema schema = Schema.builder() |
| .addInt32Field("c1") |
| .addStringField("c2") |
| .addDoubleField("c3").build(); |
| |
| // 10 rows with 0 ~ 9. |
| final List<Row> rows = IntStream.range(0, 10) |
| .mapToObj(i -> Row.withSchema(schema).addValues(i, "row", (double) i).build()) |
| .collect(Collectors.toList()); |
| |
| // Create a source PCollection |
| final PCollection<Row> inputTable = PBegin.in(p) |
| .apply(Create.of(rows).withCoder(RowCoder.of(schema))) |
| .setRowSchema(schema); |
| |
| // Run 2 SQL queries |
| // ==> Sum of ints larger than 1 |
| final PCollection<Row> firstQueryResult = |
| inputTable.apply(SqlTransform.query("select c1, c2, c3 from PCOLLECTION where c1 > 1")); |
| final PCollection<Row> secondQueryResult = PCollectionTuple |
| .of(new TupleTag<>("FIRST_QUERY_RESULT"), firstQueryResult) |
| .apply(SqlTransform.query("select c2, sum(c3) from FIRST_QUERY_RESULT group by c2")); |
| |
| // Write results to a file |
| // The result should be 2 + 3 + 4 + ... + 9 = 44 |
| GenericSourceSink.write(secondQueryResult.apply(MapElements.via(new SimpleFunction<Row, String>() { |
| @Override |
| public String apply(final Row input) { |
| final String c2 = input.getString(0); |
| final Double c3 = input.getDouble(1); |
| return c2 + " is " + c3; |
| } |
| })), outputFilePath); |
| |
| p.run().waitUntilFinish(); |
| } |
| } |