PgLastStatementSample.java

/*
 * Copyright 2025 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.spanner;

import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.Options;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;

/**
 * Sample showing how to set the last statement option when a DML statement is the last statement in a transaction.
 */
public class PgLastStatementSample {

    static void insertAndUpdateUsingLastStatement() {
        // TODO(developer): Replace these variables before running the sample.
        final String projectId = "my-project";
        final String instanceId = "my-instance";
        final String databaseId = "my-database";

        try (Spanner spanner =
                     SpannerOptions.newBuilder().setProjectId(projectId).build().getService()) {
            final DatabaseClient databaseClient =
                    spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
            insertAndUpdateUsingLastStatement(databaseClient);
        }
    }

    // [START spanner_postgresql_last_statement]
    static void insertAndUpdateUsingLastStatement(DatabaseClient client) {
        client
                .readWriteTransaction()
                .run(
                        transaction -> {
                            transaction.executeUpdate(
                                    Statement.of(
                                            "INSERT INTO Singers (SingerId, FirstName, LastName) "
                                                    + "VALUES (54214, 'John', 'Do')"));
                            System.out.println("New singer inserted.");

                            // Pass in the `lastStatement` option to the last DML statement of the transaction.
                            transaction.executeUpdate(
                                    Statement.of(
                                            "UPDATE Singers SET LastName = 'Doe' WHERE SingerId = 54214\n"),
                                    Options.lastStatement());
                            System.out.println("Singer last name updated.");

                            return null;
                        });
    }
    // [END spanner_postgresql_last_statement]

}