From 4787dd07202b6312b1a25957fee6a14e500dce48 Mon Sep 17 00:00:00 2001 From: Praful Makani Date: Fri, 24 Jul 2020 20:51:25 +0530 Subject: [PATCH] docs(samples): add query legacy large results (#594) --- .../example/bigquery/QueryLargeResults.java | 68 ++++++++++++++++++ .../example/bigquery/QueryLargeResultsIT.java | 72 +++++++++++++++++++ 2 files changed, 140 insertions(+) create mode 100644 samples/snippets/src/main/java/com/example/bigquery/QueryLargeResults.java create mode 100644 samples/snippets/src/test/java/com/example/bigquery/QueryLargeResultsIT.java diff --git a/samples/snippets/src/main/java/com/example/bigquery/QueryLargeResults.java b/samples/snippets/src/main/java/com/example/bigquery/QueryLargeResults.java new file mode 100644 index 000000000..9a4fdd3c7 --- /dev/null +++ b/samples/snippets/src/main/java/com/example/bigquery/QueryLargeResults.java @@ -0,0 +1,68 @@ +/* + * 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_legacy_large_results] +import com.google.cloud.bigquery.BigQuery; +import com.google.cloud.bigquery.BigQueryException; +import com.google.cloud.bigquery.BigQueryOptions; +import com.google.cloud.bigquery.QueryJobConfiguration; +import com.google.cloud.bigquery.TableId; +import com.google.cloud.bigquery.TableResult; + +// Sample to run query with large results and save the results to a table. +public class QueryLargeResults { + + public static void runQueryLargeResults() { + // TODO(developer): Replace these variables before running the sample. + String destinationDataset = "MY_DESTINATION_DATASET_NAME"; + String destinationTable = "MY_DESTINATION_TABLE_NAME"; + String query = "SELECT corpus FROM [bigquery-public-data:samples.shakespeare] GROUP BY corpus;"; + queryLargeResults(destinationDataset, destinationTable, query); + } + + public static void queryLargeResults( + String destinationDataset, String destinationTable, String query) { + 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 = + // To use legacy SQL syntax, set useLegacySql to true. + QueryJobConfiguration.newBuilder(query) + .setUseLegacySql(true) + // Save the results of the query to a permanent table. + .setDestinationTable(TableId.of(destinationDataset, destinationTable)) + // Allow results larger than the maximum response size. + // If true, a destination table must be set. + .setAllowLargeResults(true) + .build(); + + TableResult results = bigquery.query(queryConfig); + + results + .iterateAll() + .forEach(row -> row.forEach(val -> System.out.printf("%s,", val.toString()))); + + System.out.println("Query large results performed successfully."); + } catch (BigQueryException | InterruptedException e) { + System.out.println("Query not performed \n" + e.toString()); + } + } +} +// [END bigquery_query_legacy_large_results] diff --git a/samples/snippets/src/test/java/com/example/bigquery/QueryLargeResultsIT.java b/samples/snippets/src/test/java/com/example/bigquery/QueryLargeResultsIT.java new file mode 100644 index 000000000..cdc9007cc --- /dev/null +++ b/samples/snippets/src/test/java/com/example/bigquery/QueryLargeResultsIT.java @@ -0,0 +1,72 @@ +/* + * 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; + +import static com.google.common.truth.Truth.assertThat; +import static junit.framework.TestCase.assertNotNull; + +import java.io.ByteArrayOutputStream; +import java.io.PrintStream; +import java.util.UUID; +import org.junit.After; +import org.junit.Before; +import org.junit.BeforeClass; +import org.junit.Test; + +public class QueryLargeResultsIT { + + private String tableName; + private ByteArrayOutputStream bout; + private PrintStream out; + + private static final String BIGQUERY_DATASET_NAME = requireEnvVar("BIGQUERY_DATASET_NAME"); + + private static String requireEnvVar(String varName) { + String value = System.getenv(varName); + assertNotNull( + "Environment variable " + varName + " is required to perform these tests.", + System.getenv(varName)); + return value; + } + + @BeforeClass + public static void checkRequirements() { + requireEnvVar("BIGQUERY_DATASET_NAME"); + } + + @Before + public void setUp() { + tableName = "QUERY_LARGE_RESULT_TABLE_TEST" + UUID.randomUUID().toString().substring(0, 8); + bout = new ByteArrayOutputStream(); + out = new PrintStream(bout); + System.setOut(out); + } + + @After + public void tearDown() { + // Clean up + DeleteTable.deleteTable(BIGQUERY_DATASET_NAME, tableName); + System.setOut(null); + } + + @Test + public void testQueryLargeResults() { + String query = "SELECT corpus FROM [bigquery-public-data:samples.shakespeare] GROUP BY corpus;"; + QueryLargeResults.queryLargeResults(BIGQUERY_DATASET_NAME, tableName, query); + assertThat(bout.toString()).contains("Query large results performed successfully."); + } +}