Skip to content
Permalink
Browse files
docs(samples): add query on external temp table from gcs (#593)
  • Loading branch information
Praful Makani committed Jul 24, 2020
1 parent 8ef8db2 commit ef757ad44dcc2745f2d07b799a1af63166d79d4f
@@ -0,0 +1,77 @@
/*
* 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_external_gcs_temp]
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.TableResult;

// Sample to queries an external data source using a temporary table
public class QueryExternalGCSTemp {

public static void runQueryExternalGCSTemp() {
// TODO(developer): Replace these variables before running the sample.
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 WHERE name LIKE 'W%%'", tableName);
queryExternalGCSTemp(tableName, sourceUri, schema, query);
}

public static void queryExternalGCSTemp(
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();

// Skip header row in the file.
CsvOptions csvOptions = CsvOptions.newBuilder().setSkipLeadingRows(1).build();

// Configure the external data source and query job.
ExternalTableDefinition externalTable =
ExternalTableDefinition.newBuilder(sourceUri, csvOptions).setSchema(schema).build();
QueryJobConfiguration queryConfig =
QueryJobConfiguration.newBuilder(query)
.addTableDefinition(tableName, externalTable)
.build();

// Example query to find states starting with 'W'
TableResult results = bigquery.query(queryConfig);

results
.iterateAll()
.forEach(row -> row.forEach(val -> System.out.printf("%s,", val.toString())));

System.out.println("Query on external temporary table performed successfully.");
} catch (BigQueryException | InterruptedException e) {
System.out.println("Query not performed \n" + e.toString());
}
}
}
// [END bigquery_query_external_gcs_temp]
@@ -0,0 +1,62 @@
/*
* 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 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.Test;

public class QueryExternalGCSTempIT {

private ByteArrayOutputStream bout;
private PrintStream out;

@Before
public void setUp() {
bout = new ByteArrayOutputStream();
out = new PrintStream(bout);
System.setOut(out);
}

@After
public void tearDown() {
System.setOut(null);
}

@Test
public void testQueryExternalGCSTemp() {
String tableName =
"EXTERNAL_CSV_TEMP_TABLE_FROM_GCS_TEST_" + UUID.randomUUID().toString().substring(0, 8);
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 WHERE name LIKE 'W%%'", tableName);
QueryExternalGCSTemp.queryExternalGCSTemp(tableName, sourceUri, schema, query);
assertThat(bout.toString())
.contains("Query on external temporary table performed successfully.");
}
}

0 comments on commit ef757ad

Please sign in to comment.