feat: new sample - Tables: Relax column (#89)

samples/pom.xml

@@ -27,7 +27,6 @@
     <groupId>com.google.cloud.samples</groupId>
     <artifactId>shared-configuration</artifactId>
     <version>1.0.11</version>
-    <relativePath></relativePath>
   </parent>
 
   <properties>

samples/src/main/java/com/example/bigquery/RelaxColumnMode.java

@@ -0,0 +1,76 @@
+/*
+ * 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 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.LegacySQLTypeName;
+import com.google.cloud.bigquery.Schema;
+import com.google.cloud.bigquery.StandardTableDefinition;
+import com.google.cloud.bigquery.Table;
+
+// [START bigquery_relax_column]
+public class RelaxColumnMode {
+
+  public static void runRelaxColumnMode() {
+    // TODO(developer): Replace these variables before running the sample.
+    String datasetName = "MY_DATASET_NAME";
+    String tableId = "MY_TABLE_NAME";
+    relaxColumnMode(datasetName, tableId);
+  }
+
+  public static void relaxColumnMode(String datasetName, String tableId) {
+    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();
+
+      Table table = bigquery.getTable(datasetName, tableId);
+
+      // Create new relaxed schema based on the existing table schema
+      Schema relaxedSchema =
+          Schema.of(
+              // The only supported modification you can make to a column's mode is changing it from
+              // REQUIRED to NULLABLE
+              // Changing a column's mode from REQUIRED to NULLABLE is also called column relaxation
+              // INFO: LegacySQLTypeName will be updated to StandardSQLTypeName in release 1.103.0
+              Field.newBuilder("word", LegacySQLTypeName.STRING)
+                  .setMode(Field.Mode.NULLABLE)
+                  .build(),
+              Field.newBuilder("word_count", LegacySQLTypeName.STRING)
+                  .setMode(Field.Mode.NULLABLE)
+                  .build(),
+              Field.newBuilder("corpus", LegacySQLTypeName.STRING)
+                  .setMode(Field.Mode.NULLABLE)
+                  .build(),
+              Field.newBuilder("corpus_date", LegacySQLTypeName.STRING)
+                  .setMode(Field.Mode.NULLABLE)
+                  .build());
+
+      // Update the table with the new schema
+      Table updatedTable =
+          table.toBuilder().setDefinition(StandardTableDefinition.of(relaxedSchema)).build();
+      updatedTable.update();
+      System.out.println("Table schema successfully relaxed.");
+    } catch (BigQueryException e) {
+      System.out.println("Table schema not relaxed \n" + e.toString());
+    }
+  }
+}
+// [END bigquery_relax_column]

samples/src/test/java/com/example/bigquery/RelaxColumnModeIT.java

@@ -0,0 +1,91 @@
+/*
+ * 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.Field.Mode;
+import com.google.cloud.bigquery.LegacySQLTypeName;
+import com.google.cloud.bigquery.Schema;
+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 RelaxColumnModeIT {
+  private ByteArrayOutputStream bout;
+  private PrintStream out;
+
+  private static final String BIGQUERY_DATASET_NAME = System.getenv("BIGQUERY_DATASET_NAME");
+
+  private static void requireEnvVar(String varName) {
+    assertNotNull(
+        "Environment variable " + varName + " is required to perform these tests.",
+        System.getenv(varName));
+  }
+
+  @BeforeClass
+  public static void checkRequirements() {
+    requireEnvVar("BIGQUERY_DATASET_NAME");
+  }
+
+  @Before
+  public void setUp() throws Exception {
+    bout = new ByteArrayOutputStream();
+    out = new PrintStream(bout);
+    System.setOut(out);
+  }
+
+  @After
+  public void tearDown() {
+    System.setOut(null);
+  }
+
+  @Test
+  public void testRelaxColumnMode() {
+    // Create a new table with REQUIRED columns for each test to relax its column mode since this is
+    // a one-way operation
+    String generatedTableName =
+        "gcloud_test_table_temp_" + UUID.randomUUID().toString().replace('-', '_');
+    Schema originalSchema =
+        Schema.of(
+            // The only supported modification you can make to a column's mode is changing it from
+            // REQUIRED to NULLABLE
+            // Changing a column's mode from REQUIRED to NULLABLE is also called column relaxation
+            // INFO: LegacySQLTypeName will be updated to StandardSQLTypeName in release 1.103.0
+            Field.newBuilder("word", LegacySQLTypeName.STRING).setMode(Mode.REQUIRED).build(),
+            Field.newBuilder("word_count", LegacySQLTypeName.STRING)
+                .setMode(Field.Mode.REQUIRED)
+                .build(),
+            Field.newBuilder("corpus", LegacySQLTypeName.STRING)
+                .setMode(Field.Mode.REQUIRED)
+                .build(),
+            Field.newBuilder("corpus_date", LegacySQLTypeName.STRING)
+                .setMode(Field.Mode.REQUIRED)
+                .build());
+    CreateTable.createTable(BIGQUERY_DATASET_NAME, generatedTableName, originalSchema);
+
+    // Relax table column mode
+    RelaxColumnMode.relaxColumnMode(BIGQUERY_DATASET_NAME, generatedTableName);
+    assertThat(bout.toString()).contains("Table schema successfully relaxed.");
+  }
+}