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docs(samples): add query on external table from gcs (#588)
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Praful Makani
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samples/snippets/src/main/java/com/example/bigquery/QueryExternalGCSPerm.java
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/* | ||
* 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. | ||
*/ | ||
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package com.example.bigquery; | ||
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// [START bigquery_query_external_gcs_perm] | ||
import com.google.cloud.bigquery.BigQuery; | ||
import com.google.cloud.bigquery.BigQueryException; | ||
import com.google.cloud.bigquery.BigQueryOptions; | ||
import com.google.cloud.bigquery.CsvOptions; | ||
import com.google.cloud.bigquery.ExternalTableDefinition; | ||
import com.google.cloud.bigquery.Field; | ||
import com.google.cloud.bigquery.QueryJobConfiguration; | ||
import com.google.cloud.bigquery.Schema; | ||
import com.google.cloud.bigquery.StandardSQLTypeName; | ||
import com.google.cloud.bigquery.TableId; | ||
import com.google.cloud.bigquery.TableInfo; | ||
import com.google.cloud.bigquery.TableResult; | ||
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// Sample to queries an external data source using a permanent table | ||
public class QueryExternalGCSPerm { | ||
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public static void runQueryExternalGCSPerm() { | ||
// TODO(developer): Replace these variables before running the sample. | ||
String datasetName = "MY_DATASET_NAME"; | ||
String tableName = "MY_TABLE_NAME"; | ||
String sourceUri = "gs://cloud-samples-data/bigquery/us-states/us-states.csv"; | ||
Schema schema = | ||
Schema.of( | ||
Field.of("name", StandardSQLTypeName.STRING), | ||
Field.of("post_abbr", StandardSQLTypeName.STRING)); | ||
String query = | ||
String.format("SELECT * FROM %s.%s WHERE name LIKE 'W%%'", datasetName, tableName); | ||
queryExternalGCSPerm(datasetName, tableName, sourceUri, schema, query); | ||
} | ||
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public static void queryExternalGCSPerm( | ||
String datasetName, String tableName, String sourceUri, Schema schema, 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(); | ||
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// Skip header row in the file. | ||
CsvOptions csvOptions = CsvOptions.newBuilder().setSkipLeadingRows(1).build(); | ||
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TableId tableId = TableId.of(datasetName, tableName); | ||
// Create a permanent table linked to the GCS file | ||
ExternalTableDefinition externalTable = | ||
ExternalTableDefinition.newBuilder(sourceUri, csvOptions).setSchema(schema).build(); | ||
bigquery.create(TableInfo.of(tableId, externalTable)); | ||
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// Example query to find states starting with 'W' | ||
TableResult results = bigquery.query(QueryJobConfiguration.of(query)); | ||
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results | ||
.iterateAll() | ||
.forEach(row -> row.forEach(val -> System.out.printf("%s,", val.toString()))); | ||
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System.out.println("Query on external permanent table performed successfully."); | ||
} catch (BigQueryException | InterruptedException e) { | ||
System.out.println("Query not performed \n" + e.toString()); | ||
} | ||
} | ||
} | ||
// [END bigquery_query_external_gcs_perm] |
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samples/snippets/src/test/java/com/example/bigquery/QueryExternalGCSPermIT.java
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/* | ||
* 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. | ||
*/ | ||
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package com.example.bigquery; | ||
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import static com.google.common.truth.Truth.assertThat; | ||
import static junit.framework.TestCase.assertNotNull; | ||
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import com.google.cloud.bigquery.Field; | ||
import com.google.cloud.bigquery.Schema; | ||
import com.google.cloud.bigquery.StandardSQLTypeName; | ||
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; | ||
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public class QueryExternalGCSPermIT { | ||
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private String tableName; | ||
private ByteArrayOutputStream bout; | ||
private PrintStream out; | ||
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private static final String BIGQUERY_DATASET_NAME = requireEnvVar("BIGQUERY_DATASET_NAME"); | ||
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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; | ||
} | ||
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@BeforeClass | ||
public static void checkRequirements() { | ||
requireEnvVar("BIGQUERY_DATASET_NAME"); | ||
} | ||
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@Before | ||
public void setUp() { | ||
bout = new ByteArrayOutputStream(); | ||
out = new PrintStream(bout); | ||
System.setOut(out); | ||
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// Create a test table | ||
tableName = "EXTERNAL_CSV_TABLE_FROM_GCS_TEST_" + UUID.randomUUID().toString().substring(0, 8); | ||
bout = new ByteArrayOutputStream(); | ||
out = new PrintStream(bout); | ||
System.setOut(out); | ||
} | ||
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@After | ||
public void tearDown() { | ||
// Clean up | ||
DeleteTable.deleteTable(BIGQUERY_DATASET_NAME, tableName); | ||
System.setOut(null); | ||
} | ||
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@Test | ||
public void testQueryExternalGCSPerm() { | ||
String sourceUri = "gs://cloud-samples-data/bigquery/us-states/us-states.csv"; | ||
Schema schema = | ||
Schema.of( | ||
Field.of("name", StandardSQLTypeName.STRING), | ||
Field.of("post_abbr", StandardSQLTypeName.STRING)); | ||
String query = | ||
String.format( | ||
"SELECT * FROM %s.%s WHERE name LIKE 'W%%'", BIGQUERY_DATASET_NAME, tableName); | ||
QueryExternalGCSPerm.queryExternalGCSPerm( | ||
BIGQUERY_DATASET_NAME, tableName, sourceUri, schema, query); | ||
assertThat(bout.toString()) | ||
.contains("Query on external permanent table performed successfully."); | ||
} | ||
} |