Lee datos

Con las bibliotecas cliente de Cloud Bigtable, puedes leer datos de una tabla. En esta página, se proporcionan ejemplos de cada tipo de solicitud de lectura en varios lenguajes. Para obtener una descripción general, consulta Lecturas.

Lee una sola fila

En las siguientes muestras de código, se indica cómo obtener una fila única de datos mediante la clave de fila.

Go

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.NewAdminClient: %v", err)
	}
	tbl := client.Open(tableName)
	rowkey := "phone#4c410523#20190501"
	row, err := tbl.ReadRow(ctx, rowkey)
	if err != nil {
		log.Fatalf("Could not read row with key %s: %v", rowkey, err)
	}

	printRow(w, row)

	return nil
}

HBase

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 (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

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, rowkey);
    printRow(row);

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

Python

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#


/// <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++

Este ejemplo de código estará disponible próximamente.

Node.js

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

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

PHP

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

print_row($rowkey, $row);

Ruby

  bigtable = Google::Cloud::Bigtable.new project_id: project_id
  table = bigtable.table instance_id, table_id

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

Lee una fila parcial

En las siguientes muestras de código, se indica cómo obtener columnas específicas de una fila.

Go

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.NewAdminClient: %v", err)
	}
	tbl := client.Open(tableName)
	rowkey := "phone#4c410523#20190501"
	row, err := tbl.ReadRow(ctx, rowkey, bigtable.RowFilter(bigtable.ColumnFilter("os_build")))
	if err != nil {
		log.Fatalf("Could not read row with key %s: %v", rowkey, err)
	}

	printRow(w, row)

	return nil
}

HBase

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 (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

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, rowkey, filter);
    printRow(row);

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

Python

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#


/// <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++

Este ejemplo de código estará disponible próximamente.

Node.js

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

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

print_row($rowkey, $row);

Ruby

  bigtable = Google::Cloud::Bigtable.new project_id: project_id
  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

Lee varias filas

En las siguientes muestras de código, se muestra cómo obtener varias filas de datos mediante un conjunto de claves de fila.

Go

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.NewAdminClient: %v", err)
	}
	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 = client.Close(); err != nil {
		return fmt.Errorf("client.Close(): %v", err)
	}

	return nil
}

HBase

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 (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

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).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

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#



/// <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 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 = "";
    readRowsStream.ForEach(row => result += printRow(row));

    return result;
}

C++

Este ejemplo de código estará disponible próximamente.

Node.js

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

PHP

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

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

Ruby

bigtable = Google::Cloud::Bigtable.new project_id: project_id
table = bigtable.table instance_id, table_id

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

Lee un rango de filas

En las siguientes muestras de código, se indica cómo obtener varias filas de datos mediante una clave de inicio y una clave de finalización.

Go

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.NewAdminClient: %v", err)
	}
	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 = client.Close(); err != nil {
		return fmt.Errorf("client.Close(): %v", err)
	}

	return nil
}

HBase

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. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  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

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).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

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#


/// <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 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 = "";
    readRowsStream.ForEach(row => result += printRow(row));

    return result;
}

C++

Este ejemplo de código estará disponible próximamente.

Node.js

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

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

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

Ruby

bigtable = Google::Cloud::Bigtable.new project_id: project_id
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

Lee varios rangos de filas

En las siguientes muestras de código, se indica cómo obtener varias filas de datos mediante varias claves iniciales y finales.

Go

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.NewAdminClient: %v", err)
	}
	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 = client.Close(); err != nil {
		return fmt.Errorf("client.Close(): %v", err)
	}

	return nil
}

HBase

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 (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

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)
            .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

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#


/// <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 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 = "";
    readRowsStream.ForEach(row => result += printRow(row));

    return result;
}

C++

Este ejemplo de código estará disponible próximamente.

Node.js

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

$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

bigtable = Google::Cloud::Bigtable.new project_id: project_id
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

Lee varias filas mediante un prefijo de clave de fila

En las siguientes muestras de código, se indica cómo obtener varias filas de datos mediante un prefijo de clave de fila.

Go

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

	if err = client.Close(); err != nil {
		return fmt.Errorf("client.Close(): %v", err)
	}

	return nil
}

HBase

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 (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

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).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

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#


/// <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 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 = "";
    readRowsStream.ForEach(row => result += printRow(row));

    return result;
}

C++

Este ejemplo de código estará disponible próximamente.

Node.js

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

$prefix = 'phone#';
$end = $prefix;
$end[-1] = chr(
    ord($end[-1]) + 1
);

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

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

Ruby

bigtable = Google::Cloud::Bigtable.new project_id: project_id
table = bigtable.table instance_id, table_id

prefix = "phone#"
range = table.new_row_range.between prefix, prefix.next
table.read_rows(ranges: range).each do |row|
  print_row row
end

Lectura con filtros

En las siguientes muestras de código, se indica cómo obtener varias filas de datos mediante un filtro de filas. Para obtener más información sobre los tipos de filtros que puedes usar en las solicitudes de lectura, consulta la descripción general de filtros. También hay muestras de código adicionales que indican cómo implementar varios tipos de filtros en varios lenguajes.

Go

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.NewAdminClient: %v", err)
	}
	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 = client.Close(); err != nil {
		return fmt.Errorf("client.Close(): %v", err)
	}

	return nil
}

HBase

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. After completing all of your requests, call
  // the "close" method on the client to safely clean up any remaining background resources.
  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

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).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

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#


/// <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 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 = "";
    readRowsStream.ForEach(row => result += printRow(row));

    return result;
}

C++

Este ejemplo de código estará disponible próximamente.

Node.js

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

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

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

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

Ruby

bigtable = Google::Cloud::Bigtable.new project_id: project_id
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

Próximos pasos