Consulta con el parámetro BOOL

Consulta datos mediante un parámetro BOOL.

Muestra de código

C++

Para obtener información sobre cómo instalar y usar la biblioteca cliente de Spanner, consulta Bibliotecas cliente de Spanner.

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

void QueryWithBoolParameter(google::cloud::spanner::Client client) {
  namespace spanner = ::google::cloud::spanner;
  bool example_bool = true;
  spanner::SqlStatement select(
      "SELECT VenueId, VenueName, OutdoorVenue FROM Venues"
      " WHERE OutdoorVenue = @outdoor_venue",
      {{"outdoor_venue", spanner::Value(example_bool)}});
  using RowType = std::tuple<std::int64_t, absl::optional<std::string>,
                             absl::optional<bool>>;
  auto rows = client.ExecuteQuery(std::move(select));
  for (auto& row : spanner::StreamOf<RowType>(rows)) {
    if (!row) throw std::move(row).status();
    std::cout << "VenueId: " << std::get<0>(*row) << "\t";
    std::cout << "VenueName: " << std::get<1>(*row).value() << "\t";
    std::cout << "OutdoorVenue: " << std::get<2>(*row).value() << "\n";
  }
  std::cout << "Query completed for [spanner_query_with_bool_parameter]\n";
}

C#

Para obtener información sobre cómo instalar y usar la biblioteca cliente de Spanner, consulta Bibliotecas cliente de Spanner.


using Google.Cloud.Spanner.Data;
using System.Collections.Generic;
using System.Threading.Tasks;

public class QueryWithBoolAsyncSample
{
    public class Venue
    {
        public int VenueId { get; set; }
        public string VenueName { get; set; }
        public bool OutdoorVenue { get; set; }
    }

    public async Task<List<Venue>> QueryWithBoolAsync(string projectId, string instanceId, string databaseId)
    {
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        bool exampleBool = true;

        using var connection = new SpannerConnection(connectionString);
        var cmd = connection.CreateSelectCommand(
            "SELECT VenueId, VenueName, OutdoorVenue FROM Venues "
            + "WHERE OutdoorVenue = @ExampleBool");
        cmd.Parameters.Add("ExampleBool", SpannerDbType.Bool, exampleBool);

        var venues = new List<Venue>();
        using var reader = await cmd.ExecuteReaderAsync();
        while (await reader.ReadAsync())
        {
            venues.Add(new Venue
            {
                VenueId = reader.GetFieldValue<int>("VenueId"),
                VenueName = reader.GetFieldValue<string>("VenueName"),
                OutdoorVenue = reader.GetFieldValue<bool>("OutdoorVenue")
            });
        }
        return venues;
    }
}

Go

Para obtener información sobre cómo instalar y usar la biblioteca cliente de Spanner, consulta Bibliotecas cliente de Spanner.


import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/spanner"
	"google.golang.org/api/iterator"
)

func queryWithBool(w io.Writer, db string) error {
	ctx := context.Background()
	client, err := spanner.NewClient(ctx, db)
	if err != nil {
		return err
	}
	defer client.Close()

	var exampleBool = true
	stmt := spanner.Statement{
		SQL: `SELECT VenueId, VenueName, OutdoorVenue FROM Venues
            	WHERE OutdoorVenue = @outdoorVenue`,
		Params: map[string]interface{}{
			"outdoorVenue": exampleBool,
		},
	}
	iter := client.Single().Query(ctx, stmt)
	defer iter.Stop()
	for {
		row, err := iter.Next()
		if err == iterator.Done {
			return nil
		}
		if err != nil {
			return err
		}
		var venueID int64
		var venueName string
		var outdoorVenue bool
		if err := row.Columns(&venueID, &venueName, &outdoorVenue); err != nil {
			return err
		}
		fmt.Fprintf(w, "%d %s %t\n", venueID, venueName, outdoorVenue)
	}
}

Java

Para obtener información sobre cómo instalar y usar la biblioteca cliente de Spanner, consulta Bibliotecas cliente de Spanner.

static void queryWithBool(DatabaseClient dbClient) {
  boolean exampleBool = true;
  Statement statement =
      Statement.newBuilder(
              "SELECT VenueId, VenueName, OutdoorVenue FROM Venues "
                  + "WHERE OutdoorVenue = @outdoorVenue")
          .bind("outdoorVenue")
          .to(exampleBool)
          .build();
  try (ResultSet resultSet = dbClient.singleUse().executeQuery(statement)) {
    while (resultSet.next()) {
      System.out.printf(
          "%d %s %b\n",
          resultSet.getLong("VenueId"),
          resultSet.getString("VenueName"),
          resultSet.getBoolean("OutdoorVenue"));
    }
  }
}

Node.js

Para obtener información sobre cómo instalar y usar la biblioteca cliente de Spanner, consulta Bibliotecas cliente de Spanner.

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

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';

// Creates a client
const spanner = new Spanner({
  projectId: projectId,
});

// Gets a reference to a Cloud Spanner instance and database.
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);

const fieldType = {
  type: 'bool',
};

const exampleBool = true;

const query = {
  sql: `SELECT VenueId, VenueName, OutdoorVenue FROM Venues
          WHERE OutdoorVenue = @outdoorVenue`,
  params: {
    outdoorVenue: exampleBool,
  },
  types: {
    outdoorVenue: fieldType,
  },
};

// Queries rows from the Venues table.
try {
  const [rows] = await database.run(query);

  rows.forEach(row => {
    const json = row.toJSON();
    console.log(
      `VenueId: ${json.VenueId}, VenueName: ${json.VenueName},` +
        ` OutdoorVenue: ${json.OutdoorVenue}`
    );
  });
} catch (err) {
  console.error('ERROR:', err);
} finally {
  // Close the database when finished.
  database.close();
}

PHP

Para obtener información sobre cómo instalar y usar la biblioteca cliente de Spanner, consulta Bibliotecas cliente de Spanner.

use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Database;

/**
 * Queries sample data from the database using SQL with a BOOL parameter.
 * Example:
 * ```
 * query_data_with_bool_parameter($instanceId, $databaseId);
 * ```
 *
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 */
function query_data_with_bool_parameter(string $instanceId, string $databaseId): void
{
    $spanner = new SpannerClient();
    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);

    $exampleBool = true;

    $results = $database->execute(
        'SELECT VenueId, VenueName, OutdoorVenue FROM Venues ' .
        'WHERE OutdoorVenue = @outdoorVenue',
        [
            'parameters' => [
                'outdoorVenue' => $exampleBool
            ]
        ]
    );

    foreach ($results as $row) {
        printf('VenueId: %s, VenueName: %s, OutdoorVenue: %s' . PHP_EOL,
            $row['VenueId'], $row['VenueName'],
            $row['OutdoorVenue'] ? 'True' : 'False');
    }
}

Python

Para obtener información sobre cómo instalar y usar la biblioteca cliente de Spanner, consulta Bibliotecas cliente de Spanner.

# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)

exampleBool = True
param = {"outdoor_venue": exampleBool}
param_type = {"outdoor_venue": param_types.BOOL}

with database.snapshot() as snapshot:
    results = snapshot.execute_sql(
        "SELECT VenueId, VenueName, OutdoorVenue FROM Venues "
        "WHERE OutdoorVenue = @outdoor_venue",
        params=param,
        param_types=param_type,
    )

    for row in results:
        print("VenueId: {}, VenueName: {}, OutdoorVenue: {}".format(*row))

Ruby

Para obtener información sobre cómo instalar y usar la biblioteca cliente de Spanner, consulta Bibliotecas cliente de Spanner.

# project_id  = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new project: project_id
client  = spanner.client instance_id, database_id

sql_query = "SELECT VenueId, VenueName, OutdoorVenue FROM Venues
             WHERE OutdoorVenue = @outdoor_venue"

params      = { outdoor_venue: true }
param_types = { outdoor_venue: :BOOL }

client.execute(sql_query, params: params, types: param_types).rows.each do |row|
  puts "#{row[:VenueId]} #{row[:VenueName]} #{row[:OutdoorVenue]}"
end

¿Qué sigue?

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