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Répertorier les familles de colonnes

Répertorier les familles de colonnes.

Exemple de code

C++

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 Configurer l'authentification pour un environnement de développement local.

namespace cbt = ::google::cloud::bigtable;
namespace cbta = ::google::cloud::bigtable_admin;
using ::google::cloud::StatusOr;
[](cbta::BigtableTableAdminClient admin, std::string const& project_id,
   std::string const& instance_id, std::string const& table_id) {
  std::string table_name = cbt::TableName(project_id, instance_id, table_id);

  google::bigtable::admin::v2::GetTableRequest r;
  r.set_name(table_name);
  r.set_view(google::bigtable::admin::v2::Table::FULL);

  StatusOr<google::bigtable::admin::v2::Table> schema =
      admin.GetTable(std::move(r));

  if (!schema) throw std::move(schema).status();
  for (auto const& kv : schema->column_families()) {
    std::string const& column_family_name = kv.first;
    google::bigtable::admin::v2::ColumnFamily const& family = kv.second;
    std::cout << "Column family name: " << column_family_name << "\n"
              << "Column family metadata: " << family.DebugString() << "\n";
  }
}

Java

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

// Lists all families in the table with GC rules.
try {
  Table table = adminClient.getTable(tableId);
  Collection<ColumnFamily> columnFamilies = table.getColumnFamilies();
  for (ColumnFamily columnFamily : columnFamilies) {
    System.out.printf(
        "Column family: %s%nGC Rule: %s%n",
        columnFamily.getId(), columnFamily.getGCRule().toString());
  }
} catch (NotFoundException e) {
  System.err.println(
      "Failed to list column families from a non-existent table: " + e.getMessage());
}

Node.js

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

// List all families in the table with GC rules
const [families] = await table.getFamilies();
// Print ID, GC Rule for each column family
families.forEach(family => {
  const metadata = JSON.stringify(family.metadata);
  console.log(`Column family: ${family.id}, Metadata: ${metadata}`);
  /* Sample output:
      Column family: projects/{{projectId}}/instances/my-instance/tables/my-table/columnFamilies/cf4,
      Metadata: {"gcRule":{"intersection":{"rules":[{"maxAge":{"seconds":"432000","nanos":0},"rule":"maxAge"},{"maxNumVersions":2,"rule":"maxNumVersions"}]},"rule":"intersection"}}
  */
});

PHP

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

use Google\Cloud\Bigtable\Admin\V2\Client\BigtableTableAdminClient;
use Google\Cloud\Bigtable\Admin\V2\GetTableRequest;

/**
 * List column families of a table
 *
 * @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 for which the families need to be displayed
 */
function list_column_families(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    $tableAdminClient = new BigtableTableAdminClient();

    $tableName = $tableAdminClient->tableName($projectId, $instanceId, $tableId);
    $getTableRequest = (new GetTableRequest())
        ->setName($tableName);

    $table = $tableAdminClient->getTable($getTableRequest);
    $columnFamilies = $table->getColumnFamilies()->getIterator();

    foreach ($columnFamilies as $k => $columnFamily) {
        printf('Column Family: %s' . PHP_EOL, $k);
        print('GC Rule:' . PHP_EOL);
        printf('%s' . PHP_EOL, $columnFamily->serializeToJsonString());
    }
}

Python

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

print("Printing Column Family and GC Rule for all column families...")
column_families = table.list_column_families()
for column_family_name, gc_rule in sorted(column_families.items()):
    print("Column Family:", column_family_name)
    print("GC Rule:")
    print(gc_rule.to_pb())
    # Sample output:
    #         Column Family: cf4
    #         GC Rule:
    #         gc_rule {
    #           intersection {
    #             rules {
    #               max_age {
    #                 seconds: 432000
    #               }
    #             }
    #             rules {
    #               max_num_versions: 2
    #             }
    #           }
    #         }

Ruby

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

table = bigtable.table(
  instance_id,
  table_id,
  view:           :FULL,
  perform_lookup: true
)
table.column_families.each do |name, family|
  puts "Column family name: #{name}"
  puts "GC Rule:"
  p family.gc_rule
end

Étape suivante

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