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Exemples de lecture

Les bibliothèques clientes Cloud Bigtable permettent de lire les données d'une table. Cette page fournit des exemples de chaque type de requête de lecture dans plusieurs langages. Pour en savoir plus, consultez la section Lectures.

La bibliothèque cliente Python pour Bigtable propose deux API : asyncio et une API synchrone. Si votre application est asynchrone, utilisez asyncio.

Rôles requis

Pour obtenir les autorisations nécessaires pour lire les données d'une table, demandez à votre administrateur de vous accorder le rôle IAM Lecteur Bigtable (roles/bigtable.reader) sur la table. Pour en savoir plus sur l'attribution de rôles, consultez la page Gérer l'accès aux projets, aux dossiers et aux organisations.

Vous pouvez également obtenir les autorisations requises via des rôles personnalisés ou d'autres rôles prédéfinis.

Lire une seule ligne

Les exemples de code suivants montrent comment obtenir une seule ligne de données à l'aide de la clé de ligne.

Go

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

Pour vous authentifier auprès de Bigtable, configurez les identifiants par défaut de l'application. Pour en savoir plus, consultez la page Configurer l'authentification pour les bibliothèques clientes.

func readRow(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "mobile-time-series"

	ctx := context.Background()
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewClient: %w", err)
	}
	defer client.Close()

	tbl := client.Open(tableName)
	rowKey := "phone#4c410523#20190501"
	row, err := tbl.ReadRow(ctx, rowKey)
	if err != nil {
		return fmt.Errorf("could not read row with key %s: %w", rowKey, err)
	}

	printRow(w, row)
	return nil
}

HBase

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

/**
 * Example of reading an individual row key.
 */
public static void readRow() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRow(projectId, instanceId, tableId);
}

public static void readRow(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));

    byte[] rowkey = Bytes.toBytes("phone#4c410523#20190501");

    Result row = table.get(new Get(rowkey));
    printRow(row);

  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Java

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

public static void readRow() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRow(projectId, instanceId, tableId);
}

public static void readRow(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
    String rowkey = "phone#4c410523#20190501";

    Row row = dataClient.readRow(TableId.of(tableId), rowkey);
    printRow(row);

  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Python asyncio

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

Pour vous authentifier auprès de Bigtable, configurez le service Identifiants par défaut de l'application. Pour en savoir plus, consultez la page Configurer l'authentification pour les bibliothèques clientes.

from google.cloud.bigtable.data import BigtableDataClientAsync

async def read_row(project_id, instance_id, table_id):
    async with BigtableDataClientAsync(project=project_id) as client:
        async with client.get_table(instance_id, table_id) as table:
            row_key = "phone#4c410523#20190501"
            row = await table.read_row(row_key)
            print(row)

Python

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

def read_row(project_id, instance_id, table_id):
    client = bigtable.Client(project=project_id, admin=True)
    instance = client.instance(instance_id)
    table = instance.table(table_id)

    row_key = "phone#4c410523#20190501"

    row = table.read_row(row_key)
    print_row(row)

C#

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.


/// <summary>
/// /// Reads one row from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>
public string ReadRow(
    string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
    BigtableClient bigtableClient = BigtableClient.Create();
    TableName tableName = new TableName(projectId, instanceId, tableId);
    Row row = bigtableClient.ReadRow(tableName, rowKey: "phone#4c410523#20190501");

    return PrintRow(row);
}

C++

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

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](google::cloud::bigtable::Table table, std::string const& row_key) {
  StatusOr<std::pair<bool, cbt::Row>> tuple =
      table.ReadRow(row_key, cbt::Filter::PassAllFilter());
  if (!tuple) throw std::move(tuple).status();
  if (!tuple->first) {
    std::cout << "Row " << row_key << " not found\n";
    return;
  }
  PrintRow(tuple->second);
}

Node.js

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

const rowkey = 'phone#4c410523#20190501';

const [row] = await table.row(rowkey).get();
printRow(rowkey, row.data);

PHP

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

use Google\Cloud\Bigtable\BigtableClient;

/**
 * Read a row using the row key
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance
 * @param string $tableId The ID of the table to read from
 */
function read_row(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    // Connect to an existing table with an existing instance.
    $dataClient = new BigtableClient([
        'projectId' => $projectId,
    ]);
    $table = $dataClient->table($instanceId, $tableId);

    $rowkey = 'phone#4c410523#20190501';
    $row = $table->readRow($rowkey);

    print_row($rowkey, $row);
}

Ruby

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

  # instance_id = "my-instance"
  # table_id    = "my-table"
  bigtable = Google::Cloud::Bigtable.new
  table = bigtable.table instance_id, table_id

  row = table.read_row "phone#4c410523#20190501"
  print_row row
end

Lire une ligne partielle

Les exemples de code suivants montrent comment obtenir des colonnes spécifiques à partir d'une ligne.

Go

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

func readRowPartial(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "mobile-time-series"

	ctx := context.Background()
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewClient: %w", err)
	}
	defer client.Close()

	tbl := client.Open(tableName)
	rowKey := "phone#4c410523#20190501"
	row, err := tbl.ReadRow(ctx, rowKey, bigtable.RowFilter(bigtable.ColumnFilter("os_build")))
	if err != nil {
		return fmt.Errorf("could not read row with key %s: %w", rowKey, err)
	}

	printRow(w, row)

	return nil
}

HBase

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

/**
 * Example of reading a subset of the columns for a single row.
 */
public static void readRowPartial() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRowPartial(projectId, instanceId, tableId);
}

public static void readRowPartial(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));
    byte[] rowkey = Bytes.toBytes("phone#4c410523#20190501");

    Result row =
        table.get(
            new Get(rowkey).addColumn(Bytes.toBytes("stats_summary"), Bytes.toBytes("os_build")));
    printRow(row);

  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Java

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

public static void readRowPartial() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRowPartial(projectId, instanceId, tableId);
}

public static void readRowPartial(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
    String rowkey = "phone#4c410523#20190501";
    Filters.Filter filter =
        FILTERS
            .chain()
            .filter(FILTERS.family().exactMatch("stats_summary"))
            .filter(FILTERS.qualifier().exactMatch("os_build"));

    Row row = dataClient.readRow(TableId.of(tableId), rowkey, filter);
    printRow(row);

  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Python asyncio

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

from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import row_filters

async def read_row_partial(project_id, instance_id, table_id):
    async with BigtableDataClientAsync(project=project_id) as client:
        async with client.get_table(instance_id, table_id) as table:
            row_key = "phone#4c410523#20190501"
            col_filter = row_filters.ColumnQualifierRegexFilter(b"os_build")

            row = await table.read_row(row_key, row_filter=col_filter)
            print(row)

Python

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

def read_row_partial(project_id, instance_id, table_id):
    client = bigtable.Client(project=project_id, admin=True)
    instance = client.instance(instance_id)
    table = instance.table(table_id)

    row_key = "phone#4c410523#20190501"
    col_filter = row_filters.ColumnQualifierRegexFilter(b"os_build")

    row = table.read_row(row_key, filter_=col_filter)
    print_row(row)

C#

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


/// <summary>
/// /// Reads part of one row from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>

public string ReadRowPartial(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
    BigtableClient bigtableClient = BigtableClient.Create();
    TableName tableName = new TableName(projectId, instanceId, tableId);
    string rowkey = "phone#4c410523#20190501";
    RowFilter filter = RowFilters.ColumnQualifierExact("os_build");
    Row row = bigtableClient.ReadRow(tableName, rowkey, filter);
    return PrintRow(row);
}

C++

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](google::cloud::bigtable::Table table, std::string const& row_key) {
  StatusOr<std::pair<bool, cbt::Row>> tuple = table.ReadRow(
      row_key, cbt::Filter::ColumnName("stats_summary", "os_build"));
  if (!tuple) throw std::move(tuple).status();
  if (!tuple->first) {
    std::cout << "Row " << row_key << " not found\n";
    return;
  }
  PrintRow(tuple->second);
}

Node.js

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

const COLUMN_FAMILY = 'stats_summary';
const COLUMN_QUALIFIER = 'os_build';
const rowkey = 'phone#4c410523#20190501';

const [row] = await table
  .row(rowkey)
  .get([`${COLUMN_FAMILY}:${COLUMN_QUALIFIER}`]);

printRow(rowkey, row);

PHP

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

use Google\Cloud\Bigtable\BigtableClient;
use Google\Cloud\Bigtable\Filter;

/**
 * Read partial row data
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance
 * @param string $tableId The ID of the table to read from
 */
function read_row_partial(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    // Connect to an existing table with an existing instance.
    $dataClient = new BigtableClient([
        'projectId' => $projectId,
    ]);
    $table = $dataClient->table($instanceId, $tableId);

    $rowkey = 'phone#4c410523#20190501';
    $rowFilter = Filter::qualifier()->regex('os_build');
    $row = $table->readRow($rowkey, ['filter' => $rowFilter]);

    print_row($rowkey, $row);
}

Ruby

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

  # instance_id = "my-instance"
  # table_id    = "my-table"
  bigtable = Google::Cloud::Bigtable.new
  table = bigtable.table instance_id, table_id
  filter = Google::Cloud::Bigtable::RowFilter.qualifier "os_build"

  row = table.read_row "phone#4c410523#20190501", filter: filter
  print_row row
end

Lire plusieurs lignes

Les exemples de code suivants montrent comment obtenir plusieurs lignes de données à l'aide d'un ensemble de clés de ligne.

Go

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

func readRows(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "mobile-time-series"

	ctx := context.Background()
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewClient: %w", err)
	}
	defer client.Close()

	tbl := client.Open(tableName)
	err = tbl.ReadRows(ctx, bigtable.RowList{"phone#4c410523#20190501", "phone#4c410523#20190502"},
		func(row bigtable.Row) bool {
			printRow(w, row)
			return true
		},
	)
	if err != nil {
		return fmt.Errorf("tbl.ReadRows: %w", err)
	}

	return nil
}

HBase

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


/**
 * Example of reading multiple row keys.
 */
public static void readRows() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRows(projectId, instanceId, tableId);
}

public static void readRows(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));
    List<Get> queryRowList = new ArrayList<Get>();
    queryRowList.add(new Get(Bytes.toBytes("phone#4c410523#20190501")));
    queryRowList.add(new Get(Bytes.toBytes("phone#4c410523#20190502")));

    Result[] rows = table.get(queryRowList);

    for (Result row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Java

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

public static void readRows() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRows(projectId, instanceId, tableId);
}

public static void readRows(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
    Query query =
        Query.create(TableId.of(tableId))
            .rowKey("phone#4c410523#20190501")
            .rowKey("phone#4c410523#20190502");
    ServerStream<Row> rows = dataClient.readRows(query);
    for (Row row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Python asyncio

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import ReadRowsQuery

async def read_rows(project_id, instance_id, table_id):
    async with BigtableDataClientAsync(project=project_id) as client:
        async with client.get_table(instance_id, table_id) as table:

            query = ReadRowsQuery(
                row_keys=[b"phone#4c410523#20190501", b"phone#4c410523#20190502"]
            )
            async for row in await table.read_rows_stream(query):
                print(row)

Python

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

def read_rows(project_id, instance_id, table_id):
    client = bigtable.Client(project=project_id, admin=True)
    instance = client.instance(instance_id)
    table = instance.table(table_id)

    row_set = RowSet()
    row_set.add_row_key(b"phone#4c410523#20190501")
    row_set.add_row_key(b"phone#4c410523#20190502")

    rows = table.read_rows(row_set=row_set)
    for row in rows:
        print_row(row)

C#

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



/// <summary>
/// /// Reads multiple rows from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>
public async Task<string> ReadRows(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
    BigtableClient bigtableClient = BigtableClient.Create();
    TableName tableName = new TableName(projectId, instanceId, tableId);

    RowSet rowSet = RowSet.FromRowKeys("phone#4c410523#20190501", "phone#4c410523#20190502");
    ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, rowSet);

    string result = "";
    await foreach(var row in readRowsStream)
    {
        result += PrintRow(row);
    }

    return result;
}

C++

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

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
  // Read and print the rows.
  for (StatusOr<cbt::Row>& row : table.ReadRows(
           cbt::RowSet("phone#4c410523#20190501", "phone#4c410523#20190502"),
           cbt::Filter::PassAllFilter())) {
    if (!row) throw std::move(row).status();
    PrintRow(*row);
  }
}

Node.js

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

const rowKeys = ['phone#4c410523#20190501', 'phone#4c410523#20190502'];
const [rows] = await table.getRows({keys: rowKeys});
rows.forEach(row => printRow(row.id, row.data));

PHP

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

use Google\Cloud\Bigtable\BigtableClient;

/**
 * Read rows using an array of keys
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance
 * @param string $tableId The ID of the table to read from
 */
function read_rows(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    // Connect to an existing table with an existing instance.
    $dataClient = new BigtableClient([
        'projectId' => $projectId,
    ]);
    $table = $dataClient->table($instanceId, $tableId);

    $rows = $table->readRows(
        ['rowKeys' => ['phone#4c410523#20190501', 'phone#4c410523#20190502']]
    );

    foreach ($rows as $key => $row) {
        print_row($key, $row);
    }
}

Ruby

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

# instance_id = "my-instance"
# table_id    = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id

table.read_rows(keys: ["phone#4c410523#20190501", "phone#4c410523#20190502"]).each do |row|
  print_row row
end

Lire une plage de lignes

Les exemples de code suivants montrent comment obtenir plusieurs lignes de données à l'aide d'une clé de début et d'une clé de fin.

Go

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

func readRowRange(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "mobile-time-series"

	ctx := context.Background()
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewClient: %w", err)
	}
	defer client.Close()

	tbl := client.Open(tableName)
	err = tbl.ReadRows(ctx, bigtable.NewRange("phone#4c410523#20190501", "phone#4c410523#201906201"),
		func(row bigtable.Row) bool {
			printRow(w, row)
			return true
		},
	)

	if err != nil {
		return fmt.Errorf("tbl.ReadRows: %w", err)
	}

	return nil
}

HBase

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


/**
 * Example of reading a range of rows using a key range.
 */
public static void readRowRange() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRowRange(projectId, instanceId, tableId);
}

public static void readRowRange(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));

    Scan rangeQuery =
        new Scan()
            .withStartRow(Bytes.toBytes("phone#4c410523#20190501"))
            .withStopRow(Bytes.toBytes("phone#4c410523#201906201"));

    ResultScanner rows = table.getScanner(rangeQuery);

    for (Result row : rows) {
      printRow(row);
    }

  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Java

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

public static void readRowRange() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRowRange(projectId, instanceId, tableId);
}

public static void readRowRange(String projectId, String instanceId, String tableId) {
  String start = "phone#4c410523#20190501";
  String end = "phone#4c410523#201906201";

  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
    Query query = Query.create(TableId.of(tableId)).range(start, end);
    ServerStream<Row> rows = dataClient.readRows(query);
    for (Row row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Python asyncio

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

from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import ReadRowsQuery
from google.cloud.bigtable.data import RowRange

async def read_row_range(project_id, instance_id, table_id):
    async with BigtableDataClientAsync(project=project_id) as client:
        async with client.get_table(instance_id, table_id) as table:

            row_range = RowRange(
                start_key=b"phone#4c410523#20190501",
                end_key=b"phone#4c410523#201906201",
            )
            query = ReadRowsQuery(row_ranges=[row_range])

            async for row in await table.read_rows_stream(query):
                print(row)

Python

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

def read_row_range(project_id, instance_id, table_id):
    client = bigtable.Client(project=project_id, admin=True)
    instance = client.instance(instance_id)
    table = instance.table(table_id)

    row_set = RowSet()
    row_set.add_row_range_from_keys(
        start_key=b"phone#4c410523#20190501", end_key=b"phone#4c410523#201906201"
    )

    rows = table.read_rows(row_set=row_set)
    for row in rows:
        print_row(row)

C#

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.


/// <summary>
/// /// Reads a range of rows from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>

public async Task<string> ReadRowRange(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
    string start = "phone#4c410523#20190501";
    string end = "phone#4c410523#201906201";

    BigtableClient bigtableClient = BigtableClient.Create();
    TableName tableName = new TableName(projectId, instanceId, tableId);
    RowSet rowSet = RowSet.FromRowRanges(RowRange.ClosedOpen(start, end));
    ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, rowSet);

    string result = "";
    await foreach (var row in readRowsStream)
    {
        result += PrintRow(row);
    }

    return result;
}

C++

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

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
  // Read and print the rows.
  for (StatusOr<cbt::Row>& row :
       table.ReadRows(cbt::RowRange::Range("phone#4c410523#20190501",
                                           "phone#4c410523#201906201"),
                      cbt::Filter::PassAllFilter())) {
    if (!row) throw std::move(row).status();
    PrintRow(*row);
  }
}

Node.js

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

const start = 'phone#4c410523#20190501';
const end = 'phone#4c410523#201906201';

await table
  .createReadStream({
    start,
    end,
  })
  .on('error', err => {
    // Handle the error.
    console.log(err);
  })
  .on('data', row => printRow(row.id, row.data))
  .on('end', () => {
    // All rows retrieved.
  });

PHP

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

use Google\Cloud\Bigtable\BigtableClient;

/**
 * Read using a range for row keys
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance
 * @param string $tableId The ID of the table to read from
 */
function read_row_range(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    // Connect to an existing table with an existing instance.
    $dataClient = new BigtableClient([
        'projectId' => $projectId,
    ]);
    $table = $dataClient->table($instanceId, $tableId);

    $rows = $table->readRows([
        'rowRanges' => [
            [
                'startKeyClosed' => 'phone#4c410523#20190501',
                'endKeyOpen' => 'phone#4c410523#201906201'
            ]
        ]
    ]);

    foreach ($rows as $key => $row) {
        print_row($key, $row);
    }
}

Ruby

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

# instance_id = "my-instance"
# table_id    = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id

range = table.new_row_range.between "phone#4c410523#20190501", "phone#4c410523#201906201"
table.read_rows(ranges: range).each do |row|
  print_row row
end

Lire plusieurs plages de lignes

Les exemples de code suivants montrent comment obtenir plusieurs lignes de données à l'aide de plusieurs clés de début et de fin. Notez que la demande d'un grand nombre de plages de lignes dans une seule requête peut avoir un impact sur les performances en lecture.

Go

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

func readRowRanges(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "mobile-time-series"

	ctx := context.Background()
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewClient: %w", err)
	}
	defer client.Close()

	tbl := client.Open(tableName)
	err = tbl.ReadRows(ctx, bigtable.RowRangeList{
		bigtable.NewRange("phone#4c410523#20190501", "phone#4c410523#201906201"),
		bigtable.NewRange("phone#5c10102#20190501", "phone#5c10102#201906201"),
	},
		func(row bigtable.Row) bool {
			printRow(w, row)
			return true
		},
	)
	if err != nil {
		return fmt.Errorf("tbl.ReadRows: %w", err)
	}

	return nil
}

HBase

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

/**
 * Example of reading multiple disjoint row ranges.
 */
public static void readRowRanges() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRowRanges(projectId, instanceId, tableId);
}

public static void readRowRanges(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));
    List<RowRange> ranges = new ArrayList<>();

    ranges.add(
        new RowRange(
            Bytes.toBytes("phone#4c410523#20190501"),
            true,
            Bytes.toBytes("phone#4c410523#20190601"),
            false));
    ranges.add(
        new RowRange(
            Bytes.toBytes("phone#5c10102#20190501"),
            true,
            Bytes.toBytes("phone#5c10102#20190601"),
            false));
    Filter filter = new MultiRowRangeFilter(ranges);
    Scan scan = new Scan().setFilter(filter);

    ResultScanner rows = table.getScanner(scan);

    for (Result row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Java

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

public static void readRowRanges() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRowRanges(projectId, instanceId, tableId);
}

public static void readRowRanges(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
    Query query =
        Query.create(TableId.of(tableId))
            .range("phone#4c410523#20190501", "phone#4c410523#20190601")
            .range("phone#5c10102#20190501", "phone#5c10102#20190601");
    ServerStream<Row> rows = dataClient.readRows(query);
    for (Row row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Python

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

def read_row_ranges(project_id, instance_id, table_id):
    client = bigtable.Client(project=project_id, admin=True)
    instance = client.instance(instance_id)
    table = instance.table(table_id)

    row_set = RowSet()
    row_set.add_row_range_from_keys(
        start_key=b"phone#4c410523#20190501", end_key=b"phone#4c410523#201906201"
    )
    row_set.add_row_range_from_keys(
        start_key=b"phone#5c10102#20190501", end_key=b"phone#5c10102#201906201"
    )

    rows = table.read_rows(row_set=row_set)
    for row in rows:
        print_row(row)

C#

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.


/// <summary>
/// /// Reads multiple ranges of rows from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>

public async Task<string> ReadRowRanges(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
    BigtableClient bigtableClient = BigtableClient.Create();
    TableName tableName = new TableName(projectId, instanceId, tableId);
    RowSet rowSet = RowSet.FromRowRanges(RowRange.ClosedOpen("phone#4c410523#20190501", "phone#4c410523#20190601"),
    RowRange.ClosedOpen("phone#5c10102#20190501", "phone#5c10102#20190601"));
    ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, rowSet);

    string result = "";
    await foreach (var row in readRowsStream)
    {
        result += PrintRow(row);
    }

    return result;
}

C++

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
  // Read and print the rows.
  for (StatusOr<cbt::Row>& row : table.ReadRows(
           cbt::RowSet({cbt::RowRange::Range("phone#4c410523#20190501",
                                             "phone#4c410523#20190601"),
                        cbt::RowRange::Range("phone#5c10102#20190501",
                                             "phone#5c10102#20190601")}),
           cbt::Filter::PassAllFilter())) {
    if (!row) throw std::move(row).status();
    PrintRow(*row);
  }
}

Node.js

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

await table
  .createReadStream({
    ranges: [
      {
        start: 'phone#4c410523#20190501',
        end: 'phone#4c410523#20190601',
      },
      {
        start: 'phone#5c10102#20190501',
        end: 'phone#5c10102#20190601',
      },
    ],
  })
  .on('error', err => {
    // Handle the error.
    console.log(err);
  })
  .on('data', row => printRow(row.id, row.data))
  .on('end', () => {
    // All rows retrieved.
  });

PHP

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

use Google\Cloud\Bigtable\BigtableClient;

/**
 * Read using multiple ranges for row keys
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance
 * @param string $tableId The ID of the table to read from
 */
function read_row_ranges(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    // Connect to an existing table with an existing instance.
    $dataClient = new BigtableClient([
        'projectId' => $projectId,
    ]);
    $table = $dataClient->table($instanceId, $tableId);

    $rows = $table->readRows([
        'rowRanges' => [
            [
                'startKeyClosed' => 'phone#4c410523#20190501',
                'endKeyOpen' => 'phone#4c410523#201906201'
            ],
            [
                'startKeyClosed' => 'phone#5c10102#20190501',
                'endKeyOpen' => 'phone#5c10102#201906201'
            ]
        ]
    ]);

    foreach ($rows as $key => $row) {
        print_row($key, $row);
    }
}

Ruby

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

# instance_id = "my-instance"
# table_id    = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id

ranges = []
ranges <<
  table.new_row_range.between("phone#4c410523#20190501", "phone#4c410523#201906201") <<
  table.new_row_range.between("phone#5c10102#20190501", "phone#5c10102#201906201")
table.read_rows(ranges: ranges).each do |row|
  print_row row
end

Lire plusieurs lignes à l'aide d'un préfixe de clé de ligne

Les exemples de code suivants montrent comment obtenir plusieurs lignes de données à l'aide d'un préfixe de clé de ligne.

Go

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

func readPrefix(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "mobile-time-series"

	ctx := context.Background()
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewClient: %w", err)
	}
	defer client.Close()

	tbl := client.Open(tableName)
	err = tbl.ReadRows(ctx, bigtable.PrefixRange("phone#"),
		func(row bigtable.Row) bool {
			printRow(w, row)
			return true
		},
	)
	if err != nil {
		return fmt.Errorf("tbl.ReadRows: %w", err)
	}

	return nil
}

HBase

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.


/**
 * Example of reading a range of rows using a row prefix.
 */
public static void readPrefix() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readPrefix(projectId, instanceId, tableId);
}

public static void readPrefix(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));
    Scan prefixScan = new Scan().setRowPrefixFilter(Bytes.toBytes("phone"));
    ResultScanner rows = table.getScanner(prefixScan);

    for (Result row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Java

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

public static void readPrefix() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readPrefix(projectId, instanceId, tableId);
}

public static void readPrefix(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
    Query query = Query.create(TableId.of(tableId)).prefix("phone");
    ServerStream<Row> rows = dataClient.readRows(query);
    for (Row row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Python asyncio

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import ReadRowsQuery
from google.cloud.bigtable.data import RowRange

async def read_prefix(project_id, instance_id, table_id):
    async with BigtableDataClientAsync(project=project_id) as client:
        async with client.get_table(instance_id, table_id) as table:

            prefix = "phone#"
            end_key = prefix[:-1] + chr(ord(prefix[-1]) + 1)
            prefix_range = RowRange(start_key=prefix, end_key=end_key)
            query = ReadRowsQuery(row_ranges=[prefix_range])

            async for row in await table.read_rows_stream(query):
                print(row)

Python

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

def read_prefix(project_id, instance_id, table_id):
    client = bigtable.Client(project=project_id, admin=True)
    instance = client.instance(instance_id)
    table = instance.table(table_id)
    prefix = "phone#"
    end_key = prefix[:-1] + chr(ord(prefix[-1]) + 1)

    row_set = RowSet()
    row_set.add_row_range_from_keys(prefix.encode("utf-8"), end_key.encode("utf-8"))

    rows = table.read_rows(row_set=row_set)
    for row in rows:
        print_row(row)

C#

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


/// <summary>
/// /// Reads rows starting with a prefix from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>
public async Task<string> ReadPrefix(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
    BigtableClient bigtableClient = BigtableClient.Create();
    TableName tableName = new TableName(projectId, instanceId, tableId);

    string prefix = "phone";
    char prefixEndChar = prefix[prefix.Length - 1];
    prefixEndChar++;
    string end = prefix.Substring(0, prefix.Length - 1) + prefixEndChar;
    RowSet rowSet = RowSet.FromRowRanges(RowRange.Closed(prefix, end));
    ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, rowSet);

    string result = "";
    await foreach (var row in readRowsStream)
    {
        result += PrintRow(row);
    }

    return result;
}

C++

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
  // Read and print the rows.
  for (StatusOr<cbt::Row>& row : table.ReadRows(
           cbt::RowRange::Prefix("phone"), cbt::Filter::PassAllFilter())) {
    if (!row) throw std::move(row).status();
    PrintRow(*row);
  }
}

Node.js

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

const prefix = 'phone#';

await table
  .createReadStream({
    prefix,
  })
  .on('error', err => {
    // Handle the error.
    console.log(err);
  })
  .on('data', row => printRow(row.id, row.data))
  .on('end', () => {
    // All rows retrieved.
  });

PHP

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

use Google\Cloud\Bigtable\BigtableClient;

/**
 * Read using a row key prefix
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance
 * @param string $tableId The ID of the table to read from
 */
function read_prefix(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    // Connect to an existing table with an existing instance.
    $dataClient = new BigtableClient([
        'projectId' => $projectId,
    ]);
    $table = $dataClient->table($instanceId, $tableId);

    $prefix = 'phone#';
    $end = $prefix;
    // Increment the last character of the prefix so the filter matches everything in between
    $end[-1] = chr(
        ord($end[-1]) + 1
    );

    $rows = $table->readRows([
        'rowRanges' => [
            [
                'startKeyClosed' => $prefix,
                'endKeyClosed' => $end,
            ]
        ]
    ]);

    foreach ($rows as $key => $row) {
        print_row($key, $row);
    }
}

Ruby

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

# instance_id = "my-instance"
# table_id    = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id

prefix = "phone#"
end_key = prefix[0...-1] + prefix[-1].next
range = table.new_row_range.between prefix, end_key
table.read_rows(ranges: range).each do |row|
  print_row row
end

Analyser à l'envers

Les exemples de code suivants montrent comment effectuer une recherche à l'envers. Pour en savoir plus, consultez la page Analyses inversées : Pour éviter l'inefficacité, limiter une analyse inverse à environ 50 lignes.

Go

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

func readRowsReversed(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "mobile-time-series"

	ctx := context.Background()
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewClient: %w", err)
	}
	defer client.Close()

	tbl := client.Open(tableName)
	err = tbl.ReadRows(ctx, bigtable.NewRange("phone#5c10102", "phone#5c10103"),
		func(row bigtable.Row) bool {
			printRow(w, row)
			return true
		},
		bigtable.ReverseScan())
	if err != nil {
		return fmt.Errorf("tbl.ReadRows: %w", err)
	}

	return nil
}

HBase

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

/**
 * Example of reading a range of rows in reverse order.
 */
public static void readRowsReversed() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRowsReversed(projectId, instanceId, tableId);
}

public static void readRowsReversed(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));
    Scan revScan =
        new Scan()
            .setReversed(true)
            .setLimit(2)
            .withStartRow(Bytes.toBytes("phone#4c410523#20190505"));
    ResultScanner rows = table.getScanner(revScan);

    for (Result row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Java

Comme cet exemple utilise un préfixe et des clés de ligne de début et de fin, il renvoie un résultat de l'union de ces deux filtres.

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

public static void readRowsReversed() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readRowsReversed(projectId, instanceId, tableId);
}

public static void readRowsReversed(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
    Query query =
        Query.create(TableId.of(tableId))
            .reversed(true)
            .limit(3)
            .prefix("phone#4c410523")
            .range("phone#5c10102", "phone#5c10103");
    ServerStream<Row> rows = dataClient.readRows(query);
    for (Row row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

C++

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::Options;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
  // Read and print the rows.
  auto reader = table.ReadRows(
      cbt::RowRange::RightOpen("phone#5c10102", "phone#5c10103"), 3,
      cbt::Filter::PassAllFilter(),
      Options{}.set<cbt::ReverseScanOption>(true));
  for (StatusOr<cbt::Row>& row : reader) {
    if (!row) throw std::move(row).status();
    PrintRow(*row);
  }
}

Lire avec des filtres

Les exemples de code suivants montrent comment obtenir plusieurs lignes de données à l'aide d'un filtre de ligne. Pour en savoir plus sur les types de filtres que vous pouvez utiliser dans les requêtes de lecture, consultez la présentation des filtres. D'autres exemples de code expliquant comment mettre en œuvre différents types de filtres dans plusieurs langages sont également disponibles.

Go

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

func readFilter(w io.Writer, projectID, instanceID string, tableName string) error {
	// projectID := "my-project-id"
	// instanceID := "my-instance-id"
	// tableName := "mobile-time-series"

	ctx := context.Background()
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		return fmt.Errorf("bigtable.NewClient: %w", err)
	}
	defer client.Close()

	tbl := client.Open(tableName)
	err = tbl.ReadRows(ctx, bigtable.RowRange{},
		func(row bigtable.Row) bool {
			printRow(w, row)
			return true
		},
		bigtable.RowFilter(bigtable.ValueFilter("PQ2A.*$")),
	)
	if err != nil {
		return fmt.Errorf("tbl.ReadRows: %w", err)
	}

	return nil
}

HBase

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.


/**
 * Example of filtering row contents using filters.
 */
public static void readFilter() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readFilter(projectId, instanceId, tableId);
}

public static void readFilter(String projectId, String instanceId, String tableId) {
  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests.
  try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
    Table table = connection.getTable(TableName.valueOf(tableId));

    ValueFilter valueFilter =
        new ValueFilter(CompareOp.EQUAL, new RegexStringComparator("PQ2A.*"));
    Scan scan = new Scan().setFilter(valueFilter);

    ResultScanner rows = table.getScanner(scan);

    for (Result row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Java

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

public static void readFilter() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  readFilter(projectId, instanceId, tableId);
}

public static void readFilter(String projectId, String instanceId, String tableId) {
  Filters.Filter filter = FILTERS.value().regex("PQ2A.*");

  // Initialize client that will be used to send requests. This client only needs to be created
  // once, and can be reused for multiple requests. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
    Query query = Query.create(TableId.of(tableId)).filter(filter);
    ServerStream<Row> rows = dataClient.readRows(query);
    for (Row row : rows) {
      printRow(row);
    }
  } catch (IOException e) {
    System.out.println(
        "Unable to initialize service client, as a network error occurred: \n" + e.toString());
  }
}

Python asyncio

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

from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import ReadRowsQuery
from google.cloud.bigtable.data import row_filters

async def read_with_filter(project_id, instance_id, table_id):
    async with BigtableDataClientAsync(project=project_id) as client:
        async with client.get_table(instance_id, table_id) as table:

            row_filter = row_filters.ValueRegexFilter(b"PQ2A.*$")
            query = ReadRowsQuery(row_filter=row_filter)

            async for row in await table.read_rows_stream(query):
                print(row)

Python

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

def read_filter(project_id, instance_id, table_id):
    client = bigtable.Client(project=project_id, admin=True)
    instance = client.instance(instance_id)
    table = instance.table(table_id)

    rows = table.read_rows(filter_=row_filters.ValueRegexFilter(b"PQ2A.*$"))
    for row in rows:
        print_row(row)

C#

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


/// <summary>
/// /// Reads using a filter from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>

public async Task<string> ReadFilter(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
    BigtableClient bigtableClient = BigtableClient.Create();
    TableName tableName = new TableName(projectId, instanceId, tableId);

    RowFilter filter = RowFilters.ValueRegex("PQ2A.*");

    ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, filter: filter);
    string result = "";
    await foreach (var row in readRowsStream)
    {
        result += PrintRow(row);
    }

    return result;
}

C++

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

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
  // Read and print the rows.
  for (StatusOr<cbt::Row>& row :
       table.ReadRows(cbt::RowRange::InfiniteRange(),
                      cbt::Filter::ValueRegex("PQ2A.*"))) {
    if (!row) throw std::move(row).status();
    PrintRow(*row);
  }
}

Node.js

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

const filter = {
  value: /PQ2A.*$/,
};

await table
  .createReadStream({
    filter,
  })
  .on('error', err => {
    // Handle the error.
    console.log(err);
  })
  .on('data', row => printRow(row.id, row.data))
  .on('end', () => {
    // All rows retrieved.
  });

PHP

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

use Google\Cloud\Bigtable\BigtableClient;
use Google\Cloud\Bigtable\Filter;

/**
 * Read using a filter
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance
 * @param string $tableId The ID of the table to read from
 */
function read_filter(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    // Connect to an existing table with an existing instance.
    $dataClient = new BigtableClient([
        'projectId' => $projectId,
    ]);
    $table = $dataClient->table($instanceId, $tableId);

    $rowFilter = Filter::value()->regex('PQ2A.*$');

    $rows = $table->readRows([
        'filter' => $rowFilter
    ]);

    foreach ($rows as $key => $row) {
        print_row($key, $row);
    }
}

Ruby

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

# instance_id = "my-instance"
# table_id    = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id

filter = Google::Cloud::Bigtable::RowFilter.value "PQ2A.*$"
table.read_rows(filter: filter).each do |row|
  print_row row
end

Lire les données d'une vue autorisée

Les exemples suivants montrent comment envoyer une requête de lecture à une vue autorisée. La syntaxe est semblable à la lecture d'un tableau, sauf que vous devez également fournir le ID de la vue autorisée.

Java

Cet exemple montre comment lire une seule ligne à partir d'une vue autorisée.

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

try {
  System.out.println("\nReading a single row by row key from an authorized view");
  Row row =
      dataClient.readRow(AuthorizedViewId.of(tableId, authorizedViewId), ROW_KEY_PREFIX + 0);
  System.out.println("Row: " + row.getKey().toStringUtf8());
  for (RowCell cell : row.getCells()) {
    System.out.printf(
        "Family: %s    Qualifier: %s    Value: %s%n",
        cell.getFamily(), cell.getQualifier().toStringUtf8(), cell.getValue().toStringUtf8());
  }
  return row;
} catch (NotFoundException e) {
  System.err.println("Failed to read from a non-existent authorized view: " + e.getMessage());
  return null;
}

Cet exemple montre comment lire à partir d'une vue autorisée avec un filtre.

Pour savoir comment installer et utiliser la bibliothèque cliente pour Bigtable, consultez la section Bibliothèques clientes Bigtable.

try {
  // A filter that matches only the most recent cell within each column
  Filter filter = FILTERS.limit().cellsPerColumn(1);
  System.out.println("\nScanning authorized view with filter");
  Query query = Query.create(AuthorizedViewId.of(tableId, authorizedViewId)).filter(filter);
  ServerStream<Row> rowStream = dataClient.readRows(query);
  List<Row> authorizedViewRows = new ArrayList<>();
  for (Row r : rowStream) {
    System.out.println("Row Key: " + r.getKey().toStringUtf8());
    authorizedViewRows.add(r);
    for (RowCell cell : r.getCells()) {
      System.out.printf(
          "Family: %s    Qualifier: %s    Value: %s%n",
          cell.getFamily(), cell.getQualifier().toStringUtf8(), cell.getValue().toStringUtf8());
    }
  }
  return authorizedViewRows;
} catch (NotFoundException e) {
  System.err.println("Failed to read a non-existent authorized view: " + e.getMessage());
  return null;
}