Query with NUMERIC parameter

Query data by using a NUMERIC parameter.

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For detailed documentation that includes this code sample, see the following:

• Work with NUMERIC data

Code sample

C++

To learn how to install and use the client library for Spanner, see Spanner client libraries.

To authenticate to Spanner, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

void QueryWithNumericParameter(google::cloud::spanner::Client client) {
  namespace spanner = ::google::cloud::spanner;

  auto revenue = spanner::MakeNumeric(100000).value();
  spanner::SqlStatement select(
      "SELECT VenueId, Revenue"
      "  FROM Venues"
      " WHERE Revenue < @revenue",
      {{"revenue", spanner::Value(std::move(revenue))}});
  using RowType = std::tuple<std::int64_t, absl::optional<spanner::Numeric>>;

  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";
    auto revenue = std::get<1>(*row).value();
    std::cout << "Revenue: " << revenue.ToString()
              << " (d.16=" << std::setprecision(16)
              << spanner::ToDouble(revenue)
              << ", i*10^2=" << spanner::ToInteger<int>(revenue, 2).value()
              << ")\n";
  }
}

C#

To learn how to install and use the client library for Spanner, see Spanner client libraries.

To authenticate to Spanner, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

using Google.Cloud.Spanner.Data;
using Google.Cloud.Spanner.V1;
using System.Collections.Generic;
using System.Threading.Tasks;

public class QueryDataWithNumericParameterAsyncSample
{
    public class Venue
    {
        public int VenueId { get; set; }
        public SpannerNumeric Revenue { get; set; }
    }

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

        using var connection = new SpannerConnection(connectionString);
        using var cmd = connection.CreateSelectCommand(
            "SELECT VenueId, Revenue FROM Venues WHERE Revenue < @maxRevenue",
            new SpannerParameterCollection
            {
                { "maxRevenue", SpannerDbType.Numeric, SpannerNumeric.Parse("100000") }
            });

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

Go

To learn how to install and use the client library for Spanner, see Spanner client libraries.

To authenticate to Spanner, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"context"
	"fmt"
	"io"
	"math/big"

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

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

	stmt := spanner.Statement{
		SQL: `SELECT VenueId, Revenue FROM Venues WHERE Revenue < @revenue`,
		Params: map[string]interface{}{
			"revenue": big.NewRat(100000, 1),
		},
	}
	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 revenue big.Rat
		if err := row.Columns(&venueID, &revenue); err != nil {
			return err
		}
		fmt.Fprintf(w, "%v %v\n", venueID, revenue)
	}
}

Java

To learn how to install and use the client library for Spanner, see Spanner client libraries.

To authenticate to Spanner, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
import java.math.BigDecimal;

class QueryWithNumericParameterSample {

  static void queryWithNumericParameter() {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "my-project";
    String instanceId = "my-instance";
    String databaseId = "my-database";

    try (Spanner spanner =
        SpannerOptions.newBuilder().setProjectId(projectId).build().getService()) {
      DatabaseClient client =
          spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
      queryWithNumericParameter(client);
    }
  }

  static void queryWithNumericParameter(DatabaseClient client) {
    Statement statement =
        Statement.newBuilder(
                "SELECT VenueId, Revenue FROM Venues WHERE Revenue < @numeric")
            .bind("numeric")
            .to(new BigDecimal("100000"))
            .build();
    try (ResultSet resultSet = client.singleUse().executeQuery(statement)) {
      while (resultSet.next()) {
        System.out.printf(
            "%d %s%n", resultSet.getLong("VenueId"), resultSet.getBigDecimal("Revenue"));
      }
    }
  }
}

Node.js

To learn how to install and use the client library for Spanner, see Spanner client libraries.

To authenticate to Spanner, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

// 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: 'numeric',
};

const exampleNumeric = Spanner.numeric('100000');

const query = {
  sql: `SELECT VenueId, VenueName, Revenue FROM Venues
          WHERE Revenue < @revenue`,
  params: {
    revenue: exampleNumeric,
  },
  types: {
    revenue: 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}, Revenue: ${json.Revenue.value}`);
  });
} catch (err) {
  console.error('ERROR:', err);
} finally {
  // Close the database when finished.
  database.close();
}

PHP

To learn how to install and use the client library for Spanner, see Spanner client libraries.

To authenticate to Spanner, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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

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

    $exampleNumeric = $spanner->numeric('100000');

    $results = $database->execute(
        'SELECT VenueId, Revenue FROM Venues ' .
        'WHERE Revenue < @revenue',
        [
            'parameters' => [
                'revenue' => $exampleNumeric
            ]
        ]
    );

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

Python

To learn how to install and use the client library for Spanner, see Spanner client libraries.

To authenticate to Spanner, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

# 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)

example_numeric = decimal.Decimal("100000")
param = {"revenue": example_numeric}
param_type = {"revenue": param_types.NUMERIC}

with database.snapshot() as snapshot:
    results = snapshot.execute_sql(
        "SELECT VenueId, Revenue FROM Venues " "WHERE Revenue < @revenue",
        params=param,
        param_types=param_type,
    )

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

Ruby

To learn how to install and use the client library for Spanner, see Spanner client libraries.

To authenticate to Spanner, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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

require "google/cloud/spanner"
require "bigdecimal"

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

sql_query = "SELECT VenueId, Revenue FROM Venues WHERE Revenue < @revenue"

params      = { revenue: BigDecimal("100000") }
param_types = { revenue: :NUMERIC }

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

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