Consulta con el parámetro ARRAY

Consulta datos mediante un parámetro ARRAY.

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 QueryWithArrayParameter(google::cloud::spanner::Client client) {
  namespace spanner = ::google::cloud::spanner;
  std::vector<absl::CivilDay> example_array = {absl::CivilDay(2020, 10, 1),
                                               absl::CivilDay(2020, 11, 1)};
  spanner::SqlStatement select(
      "SELECT VenueId, VenueName, AvailableDate FROM Venues v,"
      " UNNEST(v.AvailableDates) as AvailableDate "
      " WHERE AvailableDate in UNNEST(@available_dates)",
      {{"available_dates", spanner::Value(example_array)}});
  using RowType = std::tuple<std::int64_t, absl::optional<std::string>,
                             absl::optional<absl::CivilDay>>;
  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 << "AvailableDate: " << std::get<2>(*row).value() << "\n";
  }
  std::cout << "Query completed for [spanner_query_with_array_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;
using System.Collections.Generic;
using System.Threading.Tasks;

public class QueryWithArrayAsyncSample
{
    public class Venue
    {
        public int VenueId { get; set; }
        public string VenueName { get; set; }
        public List<DateTime> AvailableDates { get; set; }
    }

    public async Task<List<Venue>> QueryWithArrayAsync(string projectId, string instanceId, string databaseId)
    {
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        // Initialize a list of dates to use for querying.
        var exampleList = new List<DateTime>
        {
            DateTime.Parse("2020-10-01"),
            DateTime.Parse("2020-11-01")
        };

        using var connection = new SpannerConnection(connectionString);
        var cmd = connection.CreateSelectCommand(
            "SELECT VenueId, VenueName, AvailableDate FROM Venues v, "
            + "UNNEST(v.AvailableDates) as AvailableDate "
            + "WHERE AvailableDate in UNNEST(@ExampleArray)");
        cmd.Parameters.Add("ExampleArray", SpannerDbType.ArrayOf(SpannerDbType.Date), exampleList);

        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"),
                AvailableDates = new List<DateTime> { reader.GetFieldValue<DateTime>("AvailableDate") }
            });
        }
        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"
	"time"

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

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

	var date1 = civil.Date{Year: 2020, Month: time.October, Day: 1}
	var date2 = civil.Date{Year: 2020, Month: time.November, Day: 1}
	var exampleArray = []civil.Date{date1, date2}
	stmt := spanner.Statement{
		SQL: `SELECT VenueId, VenueName, AvailableDate FROM Venues v,
            	UNNEST(v.AvailableDates) as AvailableDate
            	WHERE AvailableDate IN UNNEST(@availableDates)`,
		Params: map[string]interface{}{
			"availableDates": exampleArray,
		},
	}
	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 availableDate civil.Date
		if err := row.Columns(&venueID, &venueName, &availableDate); err != nil {
			return err
		}
		fmt.Fprintf(w, "%d %s %s\n", venueID, venueName, availableDate)
	}
}

Java

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

static void queryWithArray(DatabaseClient dbClient) {
  Value exampleArray =
      Value.dateArray(Arrays.asList(Date.parseDate("2020-10-01"), Date.parseDate("2020-11-01")));

  Statement statement =
      Statement.newBuilder(
              "SELECT VenueId, VenueName, AvailableDate FROM Venues v, "
                  + "UNNEST(v.AvailableDates) as AvailableDate "
                  + "WHERE AvailableDate in UNNEST(@availableDates)")
          .bind("availableDates")
          .to(exampleArray)
          .build();
  try (ResultSet resultSet = dbClient.singleUse().executeQuery(statement)) {
    while (resultSet.next()) {
      System.out.printf(
          "%d %s %s\n",
          resultSet.getLong("VenueId"),
          resultSet.getString("VenueName"),
          resultSet.getDate("AvailableDate"));
    }
  }
}

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: 'date',
};

const parentFieldType = {
  type: 'array',
  child: fieldType,
};

const exampleArray = ['2020-10-01', '2020-11-01'];

const query = {
  sql: `SELECT VenueId, VenueName, AvailableDate FROM Venues v,
          UNNEST(v.AvailableDates) as AvailableDate
          WHERE AvailableDate in UNNEST(@availableDates)`,
  params: {
    availableDates: exampleArray,
  },
  types: {
    availableDates: parentFieldType,
  },
};

// Queries rows from the Venues table.
try {
  const [rows] = await database.run(query);
  rows.forEach(row => {
    const availableDate = row[2]['value'];
    const json = row.toJSON();
    console.log(
      `VenueId: ${json.VenueId}, VenueName: ${
        json.VenueName
      }, AvailableDate: ${JSON.stringify(availableDate).substring(1, 11)}`
    );
  });
} 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;
use Google\Cloud\Spanner\Date;

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

    $exampleArray = [
        new Date(new \DateTime('2020-10-01')),
        new Date(new \DateTime('2020-11-01'))
    ];

    $results = $database->execute(
        'SELECT VenueId, VenueName, AvailableDate FROM Venues v, ' .
        'UNNEST(v.AvailableDates) as AvailableDate ' .
        'WHERE AvailableDate in UNNEST(@availableDates)',
        [
            'parameters' => [
                'availableDates' => $exampleArray
            ]
        ]
    );

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

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)

exampleArray = ["2020-10-01", "2020-11-01"]
param = {"available_dates": exampleArray}
param_type = {"available_dates": param_types.Array(param_types.DATE)}

with database.snapshot() as snapshot:
    results = snapshot.execute_sql(
        "SELECT VenueId, VenueName, AvailableDate FROM Venues v,"
        "UNNEST(v.AvailableDates) as AvailableDate "
        "WHERE AvailableDate in UNNEST(@available_dates)",
        params=param,
        param_types=param_type,
    )

    for row in results:
        print("VenueId: {}, VenueName: {}, AvailableDate: {}".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, AvailableDate FROM Venues v,
             UNNEST(v.AvailableDates) as AvailableDate
             WHERE AvailableDate in UNNEST(@available_dates)"

params      = { available_dates: ["2020-10-01", "2020-11-01"] }
param_types = { available_dates: [:DATE] }

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

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