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docs(samples): add load json table with overwrite data from gcs (#582)
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Praful Makani committed Jul 22, 2020
1 parent cbb1902 commit f127475100a307970a0af5227d367d790b434775
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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.
*/

package com.example.bigquery;

// [START bigquery_load_table_gcs_json_truncate]
import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.Field;
import com.google.cloud.bigquery.FormatOptions;
import com.google.cloud.bigquery.Job;
import com.google.cloud.bigquery.JobInfo;
import com.google.cloud.bigquery.LoadJobConfiguration;
import com.google.cloud.bigquery.Schema;
import com.google.cloud.bigquery.StandardSQLTypeName;
import com.google.cloud.bigquery.TableId;

// Sample to overwrite the BigQuery table data by loading a JSON file from GCS
public class LoadJsonFromGCSTruncate {

public static void runLoadJsonFromGCSTruncate() {
// 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.json";
Schema schema =
Schema.of(
Field.of("name", StandardSQLTypeName.STRING),
Field.of("post_abbr", StandardSQLTypeName.STRING));
loadJsonFromGCSTruncate(datasetName, tableName, sourceUri, schema);
}

public static void loadJsonFromGCSTruncate(
String datasetName, String tableName, String sourceUri, Schema schema) {
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();

TableId tableId = TableId.of(datasetName, tableName);
LoadJobConfiguration loadConfig =
LoadJobConfiguration.newBuilder(tableId, sourceUri)
.setFormatOptions(FormatOptions.json())
// Set the write disposition to overwrite existing table data
.setWriteDisposition(JobInfo.WriteDisposition.WRITE_TRUNCATE)
.setSchema(schema)
.build();

// Load data from a GCS JSON file into the table
Job job = bigquery.create(JobInfo.of(loadConfig));
// Blocks until this load table job completes its execution, either failing or succeeding.
job = job.waitFor();
if (job.isDone()) {
System.out.println("Table is successfully overwritten by JSON file loaded from GCS");
} else {
System.out.println(
"BigQuery was unable to load into the table due to an error:"
+ job.getStatus().getError());
}
} catch (BigQueryException | InterruptedException e) {
System.out.println("Column not added during load append \n" + e.toString());
}
}
}
// [END bigquery_load_table_gcs_json_truncate]
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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.
*/

package com.example.bigquery;

import static com.google.common.truth.Truth.assertThat;
import static junit.framework.TestCase.assertNotNull;

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;

public class LoadJsonFromGCSTruncateIT {

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 = "MY_LOAD_JSON_TABLE_FROM_GCS_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 loadLoadJsonFromGCSTruncate() {
String sourceUri = "gs://cloud-samples-data/bigquery/us-states/us-states.json";
Schema schema =
Schema.of(
Field.of("name", StandardSQLTypeName.STRING),
Field.of("post_abbr", StandardSQLTypeName.STRING));
LoadJsonFromGCSTruncate.loadJsonFromGCSTruncate(
BIGQUERY_DATASET_NAME, tableName, sourceUri, schema);
assertThat(bout.toString())
.contains("Table is successfully overwritten by JSON file loaded from GCS");
}
}

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