Read a partial row

Read a row with a specified filter.

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Code sample

C++

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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);
}

C#

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

/// <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);
}

Go

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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
}

Java

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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());
  }
}

Node.js

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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);
}

Python

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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)

Ruby

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

  # 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

What's next

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