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Enumera familias de columnas

Enumera familias de columnas.

Muestra de código

C++

Si deseas obtener información sobre cómo instalar y usar la biblioteca cliente de Bigtable, consulta las bibliotecas cliente de Bigtable.

Para autenticarte en Bigtable, configura las credenciales predeterminadas de la aplicación. Si deseas obtener más información, consulta Configura la autenticación para un entorno de desarrollo 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

Si deseas obtener información sobre cómo instalar y usar la biblioteca cliente de Bigtable, consulta las bibliotecas cliente de 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

Para aprender a instalar y usar la biblioteca cliente de Bigtable, consulta Bibliotecas cliente de 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

Si deseas obtener información sobre cómo instalar y usar la biblioteca cliente de Bigtable, consulta las bibliotecas cliente de 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

Para aprender a instalar y usar la biblioteca cliente de Bigtable, consulta Bibliotecas cliente de 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

Para aprender a instalar y usar la biblioteca cliente de Bigtable, consulta Bibliotecas cliente de 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

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