Données de mise à jour LMD

Mettre à jour des données avec le langage LMD.

En savoir plus

Pour obtenir une documentation détaillée incluant cet exemple de code, consultez les articles suivants :

Insérer, mettre à jour et supprimer des données à l'aide du langage de manipulation de données (LMD)

Exemple de code

C++

Pour savoir comment installer et utiliser la bibliothèque cliente pour Spanner, consultez la page Bibliothèques clientes Spanner.

Pour vous authentifier auprès de Spanner, configurez les Identifiants par défaut de l'application. Pour en savoir plus, consultez Configurer l'authentification pour un environnement de développement local.

void DmlStandardUpdate(google::cloud::spanner::Client client) {
  //! [commit-with-mutator]
  using ::google::cloud::StatusOr;
  namespace spanner = ::google::cloud::spanner;
  auto commit_result = client.Commit(
      [&client](spanner::Transaction txn) -> StatusOr<spanner::Mutations> {
        auto update = client.ExecuteDml(
            std::move(txn),
            spanner::SqlStatement(
                "UPDATE Albums SET MarketingBudget = MarketingBudget * 2"
                "  WHERE SingerId = 1 AND AlbumId = 1"));
        if (!update) return std::move(update).status();
        return spanner::Mutations{};
      });
  if (!commit_result) throw std::move(commit_result).status();
  //! [commit-with-mutator]
  std::cout << "Update was successful [spanner_dml_standard_update]\n";
}

C#

Pour savoir comment installer et utiliser la bibliothèque cliente pour Spanner, consultez la page Bibliothèques clientes Spanner.


using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;

public class UpdateUsingDmlCoreAsyncSample
{
    public async Task<int> UpdateUsingDmlCoreAsync(string projectId, string instanceId, string databaseId)
    {
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";

        using var connection = new SpannerConnection(connectionString);
        await connection.OpenAsync();

        using var cmd = connection.CreateDmlCommand("UPDATE Albums SET MarketingBudget = MarketingBudget * 2 WHERE SingerId = 1 and AlbumId = 1");
        int rowCount = await cmd.ExecuteNonQueryAsync();

        Console.WriteLine($"{rowCount} row(s) updated...");
        return rowCount;
    }
}

Go

Pour savoir comment installer et utiliser la bibliothèque cliente pour Spanner, consultez la page Bibliothèques clientes Spanner.


import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/spanner"
)

func updateUsingDML(w io.Writer, db string) error {
	ctx := context.Background()
	client, err := spanner.NewClient(ctx, db)
	if err != nil {
		return err
	}
	defer client.Close()

	_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
		stmt := spanner.Statement{
			SQL: `UPDATE Albums
				SET MarketingBudget = MarketingBudget * 2
				WHERE SingerId = 1 and AlbumId = 1`,
		}
		rowCount, err := txn.Update(ctx, stmt)
		if err != nil {
			return err
		}
		fmt.Fprintf(w, "%d record(s) updated.\n", rowCount)
		return nil
	})
	return err
}

Java

Pour savoir comment installer et utiliser la bibliothèque cliente pour Spanner, consultez la page Bibliothèques clientes Spanner.

static void updateUsingDml(DatabaseClient dbClient) {
  dbClient
      .readWriteTransaction()
      .run(transaction -> {
        String sql =
            "UPDATE Albums "
                + "SET MarketingBudget = MarketingBudget * 2 "
                + "WHERE SingerId = 1 and AlbumId = 1";
        long rowCount = transaction.executeUpdate(Statement.of(sql));
        System.out.printf("%d record updated.\n", rowCount);
        return null;
      });
}

Node.js

Pour savoir comment installer et utiliser la bibliothèque cliente pour Spanner, consultez la page Bibliothèques clientes Spanner.

// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';

// Creates a client
const spanner = new Spanner({
  projectId: projectId,
});

// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);

database.runTransaction(async (err, transaction) => {
  if (err) {
    console.error(err);
    return;
  }
  try {
    const [rowCount] = await transaction.runUpdate({
      sql: `UPDATE Albums SET MarketingBudget = MarketingBudget * 2
        WHERE SingerId = 1 and AlbumId = 1`,
    });

    console.log(`Successfully updated ${rowCount} record.`);
    await transaction.commit();
  } catch (err) {
    console.error('ERROR:', err);
  } finally {
    // Close the database when finished.
    database.close();
  }
});

PHP

Pour savoir comment installer et utiliser la bibliothèque cliente pour Spanner, consultez la page Bibliothèques clientes Spanner.

use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Transaction;

/**
 * Updates sample data in the database with a DML statement.
 *
 * This requires the `MarketingBudget` column which must be created before
 * running this sample. You can add the column by running the `add_column`
 * sample or by running this DDL statement against your database:
 *
 *     ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
 *
 * Example:
 * ```
 * update_data($instanceId, $databaseId);
 * ```
 *
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function update_data_with_dml(string $instanceId, string $databaseId): void
{
    $spanner = new SpannerClient();
    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);

    $database->runTransaction(function (Transaction $t) {
        $rowCount = $t->executeUpdate(
            'UPDATE Albums '
            . 'SET MarketingBudget = MarketingBudget * 2 '
            . 'WHERE SingerId = 1 and AlbumId = 1');
        $t->commit();
        printf('Updated %d row(s).' . PHP_EOL, $rowCount);
    });
}

Python

Pour savoir comment installer et utiliser la bibliothèque cliente pour Spanner, consultez la page Bibliothèques clientes Spanner.

# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"

spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)

def update_albums(transaction):
    row_ct = transaction.execute_update(
        "UPDATE Albums "
        "SET MarketingBudget = MarketingBudget * 2 "
        "WHERE SingerId = 1 and AlbumId = 1"
    )

    print("{} record(s) updated.".format(row_ct))

database.run_in_transaction(update_albums)

Ruby

Pour savoir comment installer et utiliser la bibliothèque cliente pour Spanner, consultez la page Bibliothèques clientes Spanner.

# project_id  = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new project: project_id
client  = spanner.client instance_id, database_id
row_count = 0

client.transaction do |transaction|
  row_count = transaction.execute_update(
    "UPDATE Albums
     SET MarketingBudget = MarketingBudget * 2
     WHERE SingerId = 1 and AlbumId = 1"
  )
end

puts "#{row_count} record updated."

Étapes suivantes

Pour rechercher et filtrer des exemples de code pour d'autres produits Google Cloud, consultez l'exemple de navigateur Google Cloud.