Guida rapida di Bigtable

Guida rapida per Cloud Bigtable, che mostra la connessione a un'istanza e la lettura di una riga da una tabella.

Per saperne di più

Per la documentazione dettagliata che include questo esempio di codice, consulta quanto segue:

• Librerie client Bigtable

Esempio di codice

C++

Per scoprire come installare e utilizzare la libreria client per Bigtable, consulta Librerie client Bigtable.

Per autenticarti a Bigtable, configura le credenziali predefinite dell'applicazione. Per ulteriori informazioni, vedi Configura l'autenticazione per un ambiente di sviluppo locale.

#include "google/cloud/bigtable/table.h"

int main(int argc, char* argv[]) try {
  if (argc != 4) {
    std::string const cmd = argv[0];
    auto last_slash = std::string(cmd).find_last_of('/');
    std::cerr << "Usage: " << cmd.substr(last_slash + 1)
              << " <project_id> <instance_id> <table_id>\n";
    return 1;
  }

  std::string const project_id = argv[1];
  std::string const instance_id = argv[2];
  std::string const table_id = argv[3];

  // Create a namespace alias to make the code easier to read.
  namespace cbt = ::google::cloud::bigtable;

  cbt::Table table(cbt::MakeDataConnection(),
                   cbt::TableResource(project_id, instance_id, table_id));

  std::string row_key = "r1";
  std::string column_family = "cf1";

  std::cout << "Getting a single row by row key:" << std::flush;
  google::cloud::StatusOr<std::pair<bool, cbt::Row>> result =
      table.ReadRow(row_key, cbt::Filter::FamilyRegex(column_family));
  if (!result) throw std::move(result).status();
  if (!result->first) {
    std::cout << "Cannot find row " << row_key << " in the table: " << table_id
              << "\n";
    return 0;
  }

  cbt::Cell const& cell = result->second.cells().front();
  std::cout << cell.family_name() << ":" << cell.column_qualifier() << "    @ "
            << cell.timestamp().count() << "us\n"
            << '"' << cell.value() << '"' << "\n";

  return 0;
} catch (google::cloud::Status const& status) {
  std::cerr << "google::cloud::Status thrown: " << status << "\n";
  return 1;
}

C#

Per scoprire come installare e utilizzare la libreria client per Bigtable, consulta Librerie client Bigtable.

Per autenticarti a Bigtable, configura le credenziali predefinite dell'applicazione. Per ulteriori informazioni, vedi Configura l'autenticazione per un ambiente di sviluppo locale.

using System;
using Google.Cloud.Bigtable.Common.V2;
// Imports the Google Cloud client library
using Google.Cloud.Bigtable.V2;

namespace GoogleCloudSamples.Bigtable
{
    public class QuickStart
    {
        public static int Main(string[] args)
        {
            // Your Google Cloud Platform project ID
            const string projectId = "YOUR-PROJECT-ID";
            // The name of the Cloud Bigtable instance
            const string instanceId = "YOUR-INSTANCE-ID";
            // The name of the Cloud Bigtable table
            const string tableId = "my-table";

            try
            {
                // Creates a Bigtable client
                BigtableClient bigtableClient = BigtableClient.Create();

                // Read a row from my-table using a row key
                Row row = bigtableClient.ReadRow(
                    new TableName(projectId, instanceId, tableId), "r1", RowFilters.CellsPerRowLimit(1));
                // Print the row key and data (column value, labels, timestamp)
                Console.WriteLine($"{"Row key:",-30}{row.Key.ToStringUtf8()}\n" +
                                  $"{"  Column Family:",-30}{row.Families[0].Name}\n" +
                                  $"{"    Column Qualifyer:",-30}{row.Families[0].Columns[0].Qualifier.ToStringUtf8()}\n" +
                                  $"{"      Value:",-30}{row.Families[0].Columns[0].Cells[0].Value.ToStringUtf8()}\n" +
                                  $"{"      Labels:",-30}{row.Families[0].Columns[0].Cells[0].Labels}\n" +
                                  $"{"      Timestamp:",-30}{row.Families[0].Columns[0].Cells[0].TimestampMicros}\n");
            }
            catch (Exception ex)
            {
                // Handle error performing the read operation
                Console.WriteLine($"Error reading row r1: {ex.Message}");
            }
            return 0;
        }
    }
}

Go

Per scoprire come installare e utilizzare la libreria client per Bigtable, consulta Librerie client Bigtable.

Per autenticarti a Bigtable, configura le credenziali predefinite dell'applicazione. Per ulteriori informazioni, vedi Configura l'autenticazione per un ambiente di sviluppo locale.

// Quickstart is a sample program demonstrating use of the Cloud Bigtable client
// library to read a row from an existing table.
package main

import (
	"context"
	"flag"
	"log"

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

func main() {
	projectID := "my-project-id"   // The Google Cloud Platform project ID
	instanceID := "my-instance-id" // The Google Cloud Bigtable instance ID
	tableID := "my-table"          // The Google Cloud Bigtable table

	ctx := context.Background()

	// Set up Bigtable data operations client.
	client, err := bigtable.NewClient(ctx, projectID, instanceID)
	if err != nil {
		log.Fatalf("Could not create data operations client: %v", err)
	}

	tbl := client.Open(tableID)

	// Read data in a row using a row key
	rowKey := "r1"
	columnFamilyName := "cf1"

	log.Printf("Getting a single row by row key:")
	row, err := tbl.ReadRow(ctx, rowKey)
	if err != nil {
		log.Fatalf("Could not read row with key %s: %v", rowKey, err)
	}
	log.Printf("Row key: %s\n", rowKey)
	log.Printf("Data: %s\n", string(row[columnFamilyName][0].Value))

	if err = client.Close(); err != nil {
		log.Fatalf("Could not close data operations client: %v", err)
	}
}

Java

Per scoprire come installare e utilizzare la libreria client per Bigtable, consulta Librerie client di Bigtable.

Per eseguire l'autenticazione su Bigtable, configura le credenziali predefinite dell'applicazione. Per ulteriori informazioni, vedi Configura l'autenticazione per un ambiente di sviluppo locale.

import com.google.api.gax.rpc.NotFoundException;
import com.google.cloud.bigtable.data.v2.BigtableDataClient;
import com.google.cloud.bigtable.data.v2.BigtableDataSettings;
import com.google.cloud.bigtable.data.v2.models.Row;
import com.google.cloud.bigtable.data.v2.models.RowCell;
import com.google.cloud.bigtable.data.v2.models.TableId;

public class Quickstart {

  public static void main(String... args) {
    String projectId = args[0]; // my-gcp-project-id
    String instanceId = args[1]; // my-bigtable-instance-id
    String tableId = args[2]; // my-bigtable-table-id

    quickstart(projectId, instanceId, tableId);
  }

  public static void quickstart(String projectId, String instanceId, String tableId) {
    BigtableDataSettings settings =
        BigtableDataSettings.newBuilder().setProjectId(projectId).setInstanceId(instanceId).build();

    // 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(settings)) {
      System.out.println("\nReading a single row by row key");
      Row row = dataClient.readRow(TableId.of(tableId), "r1");
      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());
      }
    } catch (NotFoundException e) {
      System.err.println("Failed to read from a non-existent table: " + e.getMessage());
    } catch (Exception e) {
      System.out.println("Error during quickstart: \n" + e.toString());
    }
  }
}

Node.js

Per scoprire come installare e utilizzare la libreria client per Bigtable, consulta Librerie client di Bigtable.

Per autenticarti a Bigtable, configura le credenziali predefinite dell'applicazione. Per maggiori informazioni, consulta Configurare l'autenticazione per un ambiente di sviluppo locale.

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

const bigtable = new Bigtable();

async function quickstart() {
  // Connect to an existing instance:my-bigtable-instance
  const instance = bigtable.instance(INSTANCE_ID);

  // Connect to an existing table:my-table
  const table = instance.table(TABLE_ID);

  // Read a row from my-table using a row key
  const [singleRow] = await table.row('r1').get();

  // Print the row key and data (column value, labels, timestamp)
  const rowData = JSON.stringify(singleRow.data, null, 4);
  console.log(`Row key: ${singleRow.id}\nData: ${rowData}`);
}
quickstart();

PHP

Per scoprire come installare e utilizzare la libreria client per Bigtable, consulta Librerie client di Bigtable.

Per eseguire l'autenticazione su Bigtable, configura le credenziali predefinite dell'applicazione. Per ulteriori informazioni, vedi Configura l'autenticazione per un ambiente di sviluppo locale.

use Google\Cloud\Bigtable\BigtableClient;

/** Uncomment and populate these variables in your code */
// $projectId = 'The Google project ID';
// $instanceId = 'The Bigtable instance ID';
// $tableId = 'The Bigtable table ID';

// Connect to an existing table with an existing instance.
$dataClient = new BigtableClient([
    'projectId' => $projectId,
]);
$table = $dataClient->table($instanceId, $tableId);
$key = 'r1';
// Read a row from my-table using a row key
$row = $table->readRow($key);

$columnFamilyId = 'cf1';
$columnId = 'c1';
// Get the Value from the Row, using the column_family_id and column_id
$value = $row[$columnFamilyId][$columnId][0]['value'];

printf("Row key: %s\nData: %s\n", $key, $value);

Python

Per scoprire come installare e utilizzare la libreria client per Bigtable, consulta Librerie client di Bigtable.

Per eseguire l'autenticazione su Bigtable, configura le credenziali predefinite dell'applicazione. Per maggiori informazioni, consulta Configurare l'autenticazione per un ambiente di sviluppo locale.

import argparse

from google.cloud import bigtable


def main(project_id="project-id", instance_id="instance-id", table_id="my-table"):
    # Create a Cloud Bigtable client.
    client = bigtable.Client(project=project_id)

    # Connect to an existing Cloud Bigtable instance.
    instance = client.instance(instance_id)

    # Open an existing table.
    table = instance.table(table_id)

    row_key = "r1"
    row = table.read_row(row_key.encode("utf-8"))

    column_family_id = "cf1"
    column_id = "c1".encode("utf-8")
    value = row.cells[column_family_id][column_id][0].value.decode("utf-8")

    print("Row key: {}\nData: {}".format(row_key, value))


if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        description=__doc__, formatter_class=argparse.ArgumentDefaultsHelpFormatter
    )
    parser.add_argument("project_id", help="Your Cloud Platform project ID.")
    parser.add_argument(
        "instance_id", help="ID of the Cloud Bigtable instance to connect to."
    )
    parser.add_argument(
        "--table", help="Existing table used in the quickstart.", default="my-table"
    )

    args = parser.parse_args()
    main(args.project_id, args.instance_id, args.table)

Ruby

Per scoprire come installare e utilizzare la libreria client per Bigtable, consulta Librerie client Bigtable.

Per autenticarti a Bigtable, configura le credenziali predefinite dell'applicazione. Per maggiori informazioni, consulta Configurare l'autenticazione per un ambiente di sviluppo locale.

# Import google bigtable client lib
require "google/cloud/bigtable"

# Instantiates a client
bigtable = Google::Cloud::Bigtable.new

# Your Cloud Bigtable instance ID
# instance_id = "my-instance"

# Your Cloud Bigtable table ID
# table_id = "my-table"

# Get table client
table = bigtable.table instance_id, table_id

# Read and print row
p table.read_row "user0000001"

Passaggi successivi

Per cercare e filtrare esempi di codice per altri prodotti Google Cloud, consulta Browser di esempio Google Cloud.