QueryScript.java

/*
 * Copyright 2020 Google LLC
 *
 * Licensed 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 com.example.bigquery;

// [START bigquery_query_script]
import com.google.api.gax.paging.Page;
import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.Job;
import com.google.cloud.bigquery.JobInfo;
import com.google.cloud.bigquery.QueryJobConfiguration;

// Sample to run query script.
public class QueryScript {

  public static void main(String[] args) {
    String script =
        "-- Declare a variable to hold names as an array.\n"
            + "DECLARE top_names ARRAY<STRING>;\n"
            + "-- Build an array of the top 100 names from the year 2017.\n"
            + "SET top_names = (\n"
            + "  SELECT ARRAY_AGG(name ORDER BY number DESC LIMIT 100)\n"
            + "  FROM `bigquery-public-data`.usa_names.usa_1910_current\n"
            + "  WHERE year = 2017\n"
            + ");\n"
            + "-- Which names appear as words in Shakespeare's plays?\n"
            + "SELECT\n"
            + "  name AS shakespeare_name\n"
            + "FROM UNNEST(top_names) AS name\n"
            + "WHERE name IN (\n"
            + "  SELECT word\n"
            + "  FROM `bigquery-public-data`.samples.shakespeare\n"
            + ");";
    queryScript(script);
  }

  public static void queryScript(String script) {
    try {
      // Initialize client that will be used to send requests. This client only needs to be created
      // once, and can be reused for multiple requests.
      BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();

      QueryJobConfiguration queryConfig = QueryJobConfiguration.newBuilder(script).build();
      Job createJob = bigquery.create(JobInfo.of(queryConfig));
      // Wait for the whole script to finish.
      JobInfo jobInfo = createJob.waitFor();
      String parentJobId = jobInfo.getJobId().getJob();

      // Fetch jobs created by the SQL script.
      Page<Job> childJobs = bigquery.listJobs(BigQuery.JobListOption.parentJobId(parentJobId));
      childJobs
          .iterateAll()
          .forEach(job -> System.out.printf("Child Job Id: ", job.getJobId().getJob()));

      System.out.println("Query script performed successfully.");
    } catch (BigQueryException | InterruptedException e) {
      System.out.println("Query not performed \n" + e.toString());
    }
  }
}
// [END bigquery_query_script]