此页面由 Cloud Translation API 翻译。

使用 JSONB 数据

本页面介绍了在使用 Spanner 时如何使用 JSONB 数据类型。

JSONB 是一种 PostgreSQL 数据类型，用于保存半结构化数据。JSONB 可保存数据采用 JavaScript 对象表示法 (JSON)格式，遵循规范 RFC 7159 中所述。

规格

Spanner JSONB 数据类型存储输入文档。这意味着：

系统不会保留引号和空白字符。
不支持注释。包含评论的事务或查询会失败。
对象键首先按键长度排序，然后按字典顺序等效对象键长度。如果存在重复的对象键，则只有最后一个就会保留一个
基元类型（string、boolean、number 和 null）具有各自的类型和值。
- 系统会精确保留 string 类型值。
- 尾随零会被保留。number 类型值的输出格式不使用科学计数法。

JSONB null 值被视为 SQL 非 NULL。例如：

SELECT null::jsonb IS NULL;  -- Returns true
SELECT 'null'::jsonb IS NULL; -- Returns false

SELECT '{"a":null}'::jsonb -> 'a' IS NULL; -- Returns false
SELECT '{"a":null}'::jsonb -> 'b' IS NULL; -- Returns true

SELECT '{"a":null}'::jsonb -> 'a'; -- Returns a JSONB 'null'
SELECT '{"a":null}'::jsonb -> 'b'; -- Returns a SQL NULL

保留 JSONB 数组元素顺序。

限制

Spanner JSONB 存在以下限制：

to_jsonb 函数的参数只能来自 PostgreSQL Spanner 支持的数据类型。
数字类型值的小数点前可以包含 4,932 位数，并且小数点后 16383 位。
标准化存储格式允许的大小上限为 10 MB。
JSONB 文档必须采用 UTF-8 编码。使用 JSONB 进行事务或查询以其他格式编码的文档会返回错误。

创建包含 JSONB 列的表

您可以在创建表时向该表添加 JSONB 列。

CREATE TABLE Venues (
 VenueId   BIGINT PRIMARY KEY,
 VenueName  VARCHAR(1024),
 VenueAddress VARCHAR(1024),
 VenueFeatures JSONB,
 DateOpened  TIMESTAMPTZ
);

示例 VenueFeatures JSONB 对象如下：

{
    "rating": 4.5,
    "capacity":"1500",
    "construction":"brick",
    "tags": [
        "multi-cuisine",
        "open-seating",
        "stage",
        "public address system"
    ]
}

在现有表中添加和移除 JSONB 列

您可以使用 ALTER 语句添加 JSONB 列并将其删除，如下所示：

ALTER TABLE Venues ADD COLUMN VenueDetails JSONB;
ALTER TABLE Venues DROP COLUMN VenueDetails;

以下示例展示了如何将名为 VenueDetails 的 JSONB 列添加到使用 Spanner 客户端库访问 Venues 表。

C++

void JsonbAddColumn(google::cloud::spanner_admin::DatabaseAdminClient client,
                    google::cloud::spanner::Database const& database) {
  std::vector<std::string> statements = {
      R"""(
        ALTER TABLE Venues
            ADD COLUMN VenueDetails JSONB
      )""",
  };
  auto metadata =
      client.UpdateDatabaseDdl(database.FullName(), statements).get();
  if (!metadata) throw std::move(metadata).status();
  std::cout << "Added JSONB column to table Venues in database "
            << database.FullName() << "\nNew DDL:\n"
            << metadata->DebugString();
}

C#


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

public class AddJsonbColumnAsyncPostgresSample
{
    public async Task AddJsonbColumnAsyncPostgres(string projectId, string instanceId, string databaseId)
    {
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        string alterStatement = $"ALTER TABLE VenueDetails ADD COLUMN Details JSONB";

        using var connection = new SpannerConnection(connectionString);
        using var ddlCmd = connection.CreateDdlCommand(alterStatement);
        await ddlCmd.ExecuteNonQueryAsync();
        Console.WriteLine($"Added the JSONB column named Details to VenueDetails table.");
    }
}

Go


import (
	"context"
	"fmt"
	"io"
	"regexp"

	database "cloud.google.com/go/spanner/admin/database/apiv1"
	adminpb "cloud.google.com/go/spanner/admin/database/apiv1/databasepb"
)

// addJsonBColumn creates a column in the database of type JSONB
func addJsonBColumn(w io.Writer, db string) error {
	// db = `projects/<project>/instances/<instance-id>/database/<database-id>`
	matches := regexp.MustCompile("^(.*)/databases/(.*)$").FindStringSubmatch(db)
	if matches == nil || len(matches) != 3 {
		return fmt.Errorf("addJsonbColumn: invalid database id %s", db)
	}

	ctx := context.Background()
	adminClient, err := database.NewDatabaseAdminClient(ctx)
	if err != nil {
		return err
	}
	defer adminClient.Close()

	op, err := adminClient.UpdateDatabaseDdl(ctx, &adminpb.UpdateDatabaseDdlRequest{
		Database: db,
		Statements: []string{
			"ALTER TABLE Venues ADD COLUMN VenueDetails JSONB",
		},
	})
	if err != nil {
		return err
	}
	if err := op.Wait(ctx); err != nil {
		return err
	}
	fmt.Fprintf(w, "Added VenueDetails column\n")
	return nil
}

Java


import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.admin.database.v1.DatabaseAdminClient;
import com.google.common.collect.ImmutableList;
import com.google.spanner.admin.database.v1.DatabaseName;
import java.util.concurrent.ExecutionException;

class AddJsonbColumnSample {

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

    addJsonbColumn(projectId, instanceId, databaseId);
  }

  static void addJsonbColumn(String projectId, String instanceId, String databaseId)
      throws InterruptedException, ExecutionException {
    try (Spanner spanner =
        SpannerOptions.newBuilder()
            .setProjectId(projectId)
            .build()
            .getService();
        DatabaseAdminClient databaseAdminClient = spanner.createDatabaseAdminClient()) {
      // JSONB datatype is only supported with PostgreSQL-dialect databases.
      // Wait for the operation to finish.
      // This will throw an ExecutionException if the operation fails.
      databaseAdminClient.updateDatabaseDdlAsync(
          DatabaseName.of(projectId, instanceId, databaseId),
          ImmutableList.of("ALTER TABLE Venues ADD COLUMN VenueDetails JSONB")).get();
      System.out.printf("Successfully added column `VenueDetails`%n");
    }
  }
}

Node.js

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

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

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

async function pgJsonbAddColumn() {
  // Gets a reference to a Cloud Spanner Database Admin Client object
  const databaseAdminClient = spanner.getDatabaseAdminClient();

  const request = ['ALTER TABLE Venues ADD COLUMN VenueDetails JSONB'];

  // Updates schema by adding a new table.
  const [operation] = await databaseAdminClient.updateDatabaseDdl({
    database: databaseAdminClient.databasePath(
      projectId,
      instanceId,
      databaseId
    ),
    statements: request,
  });
  console.log(`Waiting for operation on ${databaseId} to complete...`);
  await operation.promise();
  console.log(
    `Added jsonb column to table venues to database ${databaseId}.`
  );
}
pgJsonbAddColumn();

PHP

use Google\Cloud\Spanner\Admin\Database\V1\Client\DatabaseAdminClient;
use Google\Cloud\Spanner\Admin\Database\V1\UpdateDatabaseDdlRequest;

/**
 * Add a JSONB column to a table present in a PG Spanner database.
 *
 * @param string $projectId The Google Cloud project ID.
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 * @param string $tableName The table in which the column needs to be added.
 */
function pg_add_jsonb_column(
    string $projectId,
    string $instanceId,
    string $databaseId,
    string $tableName = 'Venues'
): void {
    $databaseAdminClient = new DatabaseAdminClient();
    $databaseName = DatabaseAdminClient::databaseName($projectId, $instanceId, $databaseId);
    $statement = sprintf('ALTER TABLE %s ADD COLUMN VenueDetails JSONB', $tableName);
    $request = new UpdateDatabaseDdlRequest([
        'database' => $databaseName,
        'statements' => [$statement]
    ]);

    $operation = $databaseAdminClient->updateDatabaseDdl($request);

    print('Waiting for operation to complete...' . PHP_EOL);
    $operation->pollUntilComplete();

    print(sprintf('Added column VenueDetails on table %s.', $tableName) . PHP_EOL);
}

Python

def add_jsonb_column(instance_id, database_id):
    """
    Alters Venues tables in the database adding a JSONB column.
    You can create the table by running the `create_table_with_datatypes`
    sample or by running this DDL statement against your database:
    CREATE TABLE Venues (
      VenueId         BIGINT NOT NULL,
      VenueName       character varying(100),
      VenueInfo       BYTEA,
      Capacity        BIGINT,
      OutdoorVenue    BOOL,
      PopularityScore FLOAT8,
      Revenue         NUMERIC,
      LastUpdateTime  SPANNER.COMMIT_TIMESTAMP NOT NULL,
      PRIMARY KEY (VenueId))
    """
    # instance_id = "your-spanner-instance"
    # database_id = "your-spanner-db-id"

    from google.cloud.spanner_admin_database_v1.types import \
        spanner_database_admin

    spanner_client = spanner.Client()
    database_admin_api = spanner_client.database_admin_api

    request = spanner_database_admin.UpdateDatabaseDdlRequest(
        database=database_admin_api.database_path(
            spanner_client.project, instance_id, database_id
        ),
        statements=["ALTER TABLE Venues ADD COLUMN VenueDetails JSONB"],
    )

    operation = database_admin_api.update_database_ddl(request)

    print("Waiting for operation to complete...")
    operation.result(OPERATION_TIMEOUT_SECONDS)

    print(
        'Altered table "Venues" on database {} on instance {}.'.format(
            database_id, instance_id
        )
    )

Ruby

require "google/cloud/spanner"

def spanner_postgresql_jsonb_add_column project_id:, instance_id:, database_id:
  # project_id  = "Your Google Cloud project ID"
  # instance_id = "Your Spanner instance ID"
  # database_id = "Your Spanner database ID"


  # Show how to add JSONB column
  db_admin_client = Google::Cloud::Spanner::Admin::Database.database_admin project: project_id

  db_path = db_admin_client.database_path project: project_id,
                                          instance: instance_id,
                                          database: database_id

  add_column_query = "ALTER TABLE Venues ADD COLUMN VenueDetails JSONB"

  job = db_admin_client.update_database_ddl database: db_path,
                                            statements: [add_column_query]

  job.wait_until_done!

  if job.error?
    puts "Error while adding column. Code: #{job.error.code}. Message: #{job.error.message}"
    raise GRPC::BadStatus.new(job.error.code, job.error.message)
  end

  puts "Added Venues column to VenueDetails table in database #{database_id}"
end

修改 JSONB 数据

您可以修改 JSONB 列，就像修改任何其他列一样。

示例如下：

UPDATE Venues SET VenueFeatures = '{"rating": 4.5, "tags":["multi-cuisine", "open-seating"] }'
  WHERE VenueId = 1;

以下示例展示了如何使用以下代码更新 JSONB 数据： Spanner 客户端库。

C++

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

void JsonbUpdateData(google::cloud::spanner::Client client) {
  auto venue19_details = google::cloud::spanner::JsonB(R"""(
        {"rating": 9, "open": true}
      )""");
  // PG.JSONB takes the last value in the case of duplicate keys.
  auto venue4_details = google::cloud::spanner::JsonB(R"""(
        [
          {"name": null, "available": true},
          {"name": "room 2", "available": false, "name": "room 3"},
          {
            "main hall": {
              "description": "this is the biggest space",
              "size": 200
            }
          }
        ]
      )""");
  auto venue42_details = google::cloud::spanner::JsonB(R"""(
        {
          "name": null,
          "open": {"Monday": true, "Tuesday": false},
          "tags": ["large", "airy"]
        }
      )""");
  auto update_venues = google::cloud::spanner::InsertOrUpdateMutationBuilder(
                           "Venues", {"VenueId", "VenueDetails"})
                           .EmplaceRow(19, venue19_details)
                           .EmplaceRow(4, venue4_details)
                           .EmplaceRow(42, venue42_details)
                           .Build();
  auto commit_result =
      client.Commit(google::cloud::spanner::Mutations{update_venues});
  if (!commit_result) throw std::move(commit_result).status();
  std::cout << "Updated data.\n";
}

C#

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。


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

public class UpdateDataWithJsonbAsyncPostgresSample
{
    public async Task UpdateDataWithJsonbAsyncPostgres(string projectId, string instanceId, string databaseId)
    {
        List<VenueInformation> venueInformationList = new List<VenueInformation>
        {
            // If you are using .NET Core 3.1 or later, you can use System.Text.Json for serialization instead.
            new VenueInformation
            {
                VenueId = 19,
                Details = JsonConvert.SerializeObject(new
                {
                    rating = 9,
                    open = true,
                })
            },
            new VenueInformation
            {
                VenueId = 4,
                // In the case of repeated field names in the JSON, PostgreSQL JSONB will keep the value of the last field appearance.
                // For instance, in the following example, the value for name will be room 3.
                Details = @"
                {
                    ""name"": ""room 2"",
                    ""available"": false,
                    ""name"": ""room 3""
                }"
            },
            new VenueInformation
            {
                VenueId = 42,
                Details = JsonConvert.SerializeObject(new
                {
                    name = "Central Park",
                    open = new
                    {
                        Monday = true,
                        Tuesday = false,
                    },
                    tags = new string[] {"large", "airy" },
                }),
            },
        };
        // Create connection to Cloud Spanner.
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        using var connection = new SpannerConnection(connectionString);
        await connection.OpenAsync();

        await Task.WhenAll(venueInformationList.Select(venue =>
        {
            // Update rows in the Venues table.
            using var cmd = connection.CreateUpdateCommand("VenueInformation", new SpannerParameterCollection
            {
                { "VenueId", SpannerDbType.Int64, venue.VenueId },
                { "Details", SpannerDbType.PgJsonb, venue.Details }
            });
            return cmd.ExecuteNonQueryAsync();
        }));
        Console.WriteLine("Data updated.");
    }

    public struct VenueInformation
    {
        public int VenueId { get; set; }
        public string Details { get; set; }
    }
}

Go

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。


import (
	"context"
	"fmt"
	"io"
	"regexp"

	"cloud.google.com/go/spanner"
)

// updateDataWithJsonBColumn updates database with JsonB type values
func updateDataWithJsonBColumn(w io.Writer, db string) error {
	// db = `projects/<project>/instances/<instance-id>/database/<database-id>`
	matches := regexp.MustCompile("^(.*)/databases/(.*)$").FindStringSubmatch(db)
	if matches == nil || len(matches) != 3 {
		return fmt.Errorf("updateDataWithJsonBColumn: invalid database id %s", db)
	}

	ctx := context.Background()
	client, err := spanner.NewClient(ctx, db)
	if err != nil {
		return err
	}
	defer client.Close()

	type VenueDetails struct {
		Name   spanner.NullString   `json:"name"`
		Rating spanner.NullFloat64  `json:"rating"`
		Open   interface{}          `json:"open"`
		Tags   []spanner.NullString `json:"tags"`
	}

	details_1 := spanner.PGJsonB{Value: []VenueDetails{
		{Name: spanner.NullString{StringVal: "room1", Valid: true}, Open: true},
		{Name: spanner.NullString{StringVal: "room2", Valid: true}, Open: false},
	}, Valid: true}
	details_2 := spanner.PGJsonB{Value: VenueDetails{
		Rating: spanner.NullFloat64{Float64: 9, Valid: true},
		Open:   true,
	}, Valid: true}

	details_3 := spanner.PGJsonB{Value: VenueDetails{
		Name: spanner.NullString{Valid: false},
		Open: map[string]bool{"monday": true, "tuesday": false},
		Tags: []spanner.NullString{{StringVal: "large", Valid: true}, {StringVal: "airy", Valid: true}},
	}, Valid: true}

	cols := []string{"VenueId", "VenueDetails"}
	_, err = client.Apply(ctx, []*spanner.Mutation{
		spanner.Update("Venues", cols, []interface{}{4, details_1}),
		spanner.Update("Venues", cols, []interface{}{19, details_2}),
		spanner.Update("Venues", cols, []interface{}{42, details_3}),
	})

	if err != nil {
		return err
	}
	fmt.Fprintf(w, "Updated data to VenueDetails column\n")

	return nil
}

Java

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.Mutation;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Value;
import com.google.common.collect.ImmutableList;

class UpdateJsonbDataSample {

  static void updateJsonbData() {
    // 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));
      updateJsonbData(client);
    }
  }

  static void updateJsonbData(DatabaseClient client) {
    // PG JSONB takes the last value in the case of duplicate keys.
    // PG JSONB sorts first by key length and then lexicographically with
    // equivalent key length.
    client.write(
        ImmutableList.of(
            Mutation.newInsertOrUpdateBuilder("Venues")
                .set("VenueId")
                .to(4L)
                .set("VenueDetails")
                .to(
                    Value.pgJsonb(
                        "[{\"name\":\"room 1\",\"open\":true,\"name\":\"room 3\"},"
                            + "{\"name\":\"room 2\",\"open\":false}]"))
                .build(),
            Mutation.newInsertOrUpdateBuilder("Venues")
                .set("VenueId")
                .to(19L)
                .set("VenueDetails")
                .to(Value.pgJsonb("{\"rating\":9,\"open\":true}"))
                .build(),
            Mutation.newInsertOrUpdateBuilder("Venues")
                .set("VenueId")
                .to(42L)
                .set("VenueDetails")
                .to(
                    Value.pgJsonb(
                        "{\"name\":null,"
                            + "\"open\":{\"Monday\":true,\"Tuesday\":false},"
                            + "\"tags\":[\"large\",\"airy\"]}"))
                .build()));
    System.out.println("Venues successfully updated");
  }
}

Node.js

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

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

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

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

async function pgJsonbUpdateData() {
  // Gets a reference to a Cloud Spanner instance and database.
  const instance = spanner.instance(instanceId);
  const database = instance.database(databaseId);
  // Instantiate Spanner table objects.
  const venuesTable = database.table('venues');

  const data = [
    {
      VenueId: '19',
      VenueDetails: {rating: 9, open: true},
    },
    {
      VenueId: '4',
      // PG JSONB sorts first by key length and then lexicographically with equivalent key length
      // and takes the last value in the case of duplicate keys
      VenueDetails: `[
      {
        "name": null,
        "available": true
      },
      {
        "name": "room 2",
        "available": false,
        "name": "room 3"
      },
      {
        "main hall": {
          "description": "this is the biggest space",
          "size": 200
        }
      }
    ]`,
    },
    {
      VenueId: '42',
      VenueDetails: {
        name: null,
        open: {
          Monday: true,
          Tuesday: false,
        },
        tags: ['large', 'airy'],
      },
    },
  ];

  try {
    await venuesTable.update(data);
    console.log('Updated data.');
  } catch (err) {
    console.error('ERROR:', err);
  } finally {
    // Close the database when finished.
    await database.close();
  }
}
pgJsonbUpdateData();

PHP

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

use Google\Cloud\Spanner\SpannerClient;

/**
 * Insert/update data in a JSONB column in a Postgres table.
 *
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 * @param string $tableName The table in which the data needs to be updated.
 */
function pg_jsonb_update_data(
    string $instanceId,
    string $databaseId,
    string $tableName = 'Venues'
): void {
    $spanner = new SpannerClient();
    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);

    $database->insertOrUpdateBatch($tableName, [
        [
            'VenueId' => 1,
            'VenueDetails' => '{"rating": 9, "open": true}'
        ],
        [
            'VenueId' => 4,
            'VenueDetails' => '[
                {
                    "name": null,
                    "available": true
                },' .
                // PG JSONB sorts first by key length and then lexicographically with
                // equivalent key length and takes the last value in the case of duplicate keys
                '{
                    "name": "room 2",
                    "available": false,
                    "name": "room 3"
                },
                {
                    "main hall": {
                        "description": "this is the biggest space",
                        "size": 200
                    }
                }
            ]'
        ],
        [
            'VenueId' => 42,
            'VenueDetails' => $spanner->pgJsonb([
                'name' => null,
                'open' => [
                    'Monday' => true,
                    'Tuesday' => false
                ],
                'tags' => ['large', 'airy'],
            ])
        ]
    ]);

    print(sprintf('Inserted/updated 3 rows in table %s', $tableName) . PHP_EOL);
}

Python

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

def update_data_with_jsonb(instance_id, database_id):
    """Updates Venues tables in the database with the JSONB
    column.
    This updates the `VenueDetails` column which must be created before
    running this sample. You can add the column by running the
    `add_jsonb_column` sample or by running this DDL statement
     against your database:
        ALTER TABLE Venues ADD COLUMN VenueDetails JSONB
    """
    # 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)

    """
    PG JSONB takes the last value in the case of duplicate keys.
    PG JSONB sorts first by key length and then lexicographically with
    equivalent key length.
    """

    with database.batch() as batch:
        batch.update(
            table="Venues",
            columns=("VenueId", "VenueDetails"),
            values=[
                (
                    4,
                    JsonObject(
                        [
                            JsonObject({"name": None, "open": True}),
                            JsonObject({"name": "room 2", "open": False}),
                        ]
                    ),
                ),
                (19, JsonObject(rating=9, open=True)),
                (
                    42,
                    JsonObject(
                        {
                            "name": None,
                            "open": {"Monday": True, "Tuesday": False},
                            "tags": ["large", "airy"],
                        }
                    ),
                ),
            ],
        )

    print("Updated data.")

Ruby

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

require "google/cloud/spanner"

def spanner_postgresql_jsonb_update_data project_id:, instance_id:, database_id:
  # project_id  = "Your Google Cloud project ID"
  # instance_id = "Your Spanner instance ID"
  # database_id = "Your Spanner database ID"

  # Insert JSONB data into table
  spanner = Google::Cloud::Spanner.new project: project_id
  client  = spanner.client instance_id, database_id

  data = [
    {
      VenueId: "19",
      VenueDetails: { rating: 9, open: true }
    },
    {
      VenueId: "4",
      VenueDetails: [
        {
          name: null,
          open: true
        },
        {
          name: "room 2",
          open: false
        },
        {
          main_hall: {
            description: "this is the biggest space",
            size: 200
          }
        }
      ]
    },
    {
      VenueId: "42",
      VenueDetails: {
        name: null,
        open: {
          Monday: true,
          Tuesday: false
        },
        tags: ["large", "airy"]
      }
    }
  ]

  client.upsert "Venues", data
  puts "Inserted data into Venues table"
end

查询 JSONB 数据

您可以根据底层字段的值查询 JSONB 列。通过以下示例从 Venues 中提取 VenueId 和 VenueName，其中 VenueFeatures 的 rating 值大于 3.5。

SELECT VenueId, VenueName FROM Venues WHERE (VenueFeatures->>'rating')::FLOAT8 > 3.5;

以下示例展示了如何使用以下代码查询 JSONB 数据： Spanner 客户端库。

C++

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

void JsonbQueryWithParameter(google::cloud::spanner::Client client) {
  auto sql = google::cloud::spanner::SqlStatement(
      "SELECT VenueId, VenueDetails FROM Venues"
      "  WHERE CAST(VenueDetails ->> 'rating' AS INTEGER) > $1",
      {{"p1", google::cloud::spanner::Value(2)}});
  using RowType =
      std::tuple<std::int64_t, absl::optional<google::cloud::spanner::JsonB>>;
  auto rows = client.ExecuteQuery(std::move(sql));
  for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
    if (!row) throw std::move(row).status();
    std::cout << "VenueId: " << std::get<0>(*row) << ", ";
    std::cout << "Details: " << std::string(std::get<1>(*row).value()) << "\n";
  }
}

C#

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。


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

public class QueryJsonbDataUsingParameterAsyncPostgresSample
{
    public async Task<List<VenueInformation>> QueryJsonbDataUsingParameterAsyncPostgres(string projectId, string instanceId, string databaseId)
    {
        string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
        using var connection = new SpannerConnection(connectionString);
        // Get all the venues with a rating greater than 2.
        /* Details is a column of type JSONB. Some of the data persisted in the Details column has the following structure:
           [{
                 "name": "string",
                 "available": true,
                 "rating": int // This field is optional.
           }] */
        using var command = connection.CreateSelectCommand(
            "SELECT venueid, details FROM VenueInformation WHERE CAST(details ->> 'rating' AS INTEGER) > $1",
            new SpannerParameterCollection
            {
                { "p1", SpannerDbType.Int64, 2 }
            });
        var venues = new List<VenueInformation>();
        using var reader = await command.ExecuteReaderAsync();
        while (await reader.ReadAsync())
        {
            venues.Add(new VenueInformation
            {
                VenueId = reader.GetFieldValue<int>("venueid"),
                Details = reader.GetFieldValue<string>("details")
            });
        }
        return venues;
    }

    public struct VenueInformation
    {
        public int VenueId { get; set; }
        public string Details { get; set; }
    }
}

Go

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。


import (
	"context"
	"fmt"
	"io"
	"regexp"

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

// queryWithJsonBParameter queries data on the JSON type column of the database
func queryWithJsonBParameter(w io.Writer, db string) error {
	// db = `projects/<project>/instances/<instance-id>/database/<database-id>`
	matches := regexp.MustCompile("^(.*)/databases/(.*)$").FindStringSubmatch(db)
	if matches == nil || len(matches) != 3 {
		return fmt.Errorf("queryWithJsonBParameter: invalid database id %s", db)
	}
	ctx := context.Background()
	client, err := spanner.NewClient(ctx, db)
	if err != nil {
		return err
	}
	defer client.Close()

	type VenueDetails struct {
		Name   spanner.NullString   `json:"name"`
		Rating spanner.NullFloat64  `json:"rating"`
		Open   interface{}          `json:"open"`
		Tags   []spanner.NullString `json:"tags"`
	}

	stmt := spanner.Statement{
		SQL: `SELECT VenueId, VenueDetails FROM Venues WHERE CAST(venuedetails ->> 'rating' AS INTEGER) > $1`,
		Params: map[string]interface{}{
			"p1": 2,
		},
	}
	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 venueDetails spanner.PGJsonB
		if err := row.Columns(&venueID, &venueDetails); err != nil {
			return err
		}
		fmt.Fprintf(w, "The venue details for venue id %v is %v\n", venueID, venueDetails)
	}
}

Java

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

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 com.google.cloud.spanner.Value;

class QueryWithJsonbParameterSample {

  static void queryWithJsonbParameter() {
    // 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));
      queryWithJsonbParameter(client);
    }
  }

  static void queryWithJsonbParameter(DatabaseClient client) {
    int rating = 2;
    Statement statement =
        Statement.newBuilder(
                "SELECT VenueId, VenueDetails\n"
                    + "FROM Venues\n"
                    + "WHERE CAST(venuedetails ->> 'rating' "
                    + "AS INTEGER) > $1")
            .bind("p1")
            .to(Value.int64(rating))
            .build();
    try (ResultSet resultSet = client.singleUse().executeQuery(statement)) {
      while (resultSet.next()) {
        System.out.printf(
            "VenueId: %s, VenueDetails: %s%n",
            resultSet.getLong("venueid"), resultSet.getPgJsonb("venuedetails"));
      }
    }
  }
}

Node.js

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

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

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

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

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

  const select_query = {
    sql: `SELECT venueid, venuedetails FROM Venues
        WHERE CAST(venuedetails ->> 'rating' AS INTEGER) > $1`,
    params: {
      p1: 2,
    },
    types: {
      p1: 'int64',
    },
    json: true,
  };

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

    rows.forEach(row => {
      console.log(
        `VenueId: ${row.venueid}, Details: ${JSON.stringify(
          row.venuedetails
        )}`
      );
    });
  } finally {
    // Close the database when finished.
    await database.close();
  }
}
pgJsonbDataType();

PHP

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。


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

/**
 * Query data to a jsonb column in a PostgreSQL table.
 *
 * @param string $instanceId The Spanner instance ID.
 * @param string $databaseId The Spanner database ID.
 * @param string $tableName The table from which the data needs to be queried.
 */
function pg_jsonb_query_parameter(
    string $instanceId,
    string $databaseId,
    string $tableName = 'Venues'
): void {
    $spanner = new SpannerClient();
    $instance = $spanner->instance($instanceId);
    $database = $instance->database($databaseId);

    $results = $database->execute(
        sprintf('SELECT venueid, venuedetails FROM %s', $tableName) .
        " WHERE CAST(venuedetails ->> 'rating' AS INTEGER) > $1",
        [
        'parameters' => [
            'p1' => 2
        ],
        'types' => [
            'p1' => Database::TYPE_INT64
        ]
    ]);

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

Python

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

def query_data_with_jsonb_parameter(instance_id, database_id):
    """Queries sample data using SQL with a JSONB parameter."""
    # 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)

    param = {"p1": 2}
    param_type = {"p1": param_types.INT64}

    with database.snapshot() as snapshot:
        results = snapshot.execute_sql(
            "SELECT venueid, venuedetails FROM Venues"
            + " WHERE CAST(venuedetails ->> 'rating' AS INTEGER) > $1",
            params=param,
            param_types=param_type,
        )

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

Ruby

如需了解如何安装和使用 Spanner 客户端库，请参阅 Spanner 客户端库。

如需向 Spanner 进行身份验证，请设置应用默认凭据。如需了解详情，请参阅为本地开发环境设置身份验证。

require "google/cloud/spanner"

def spanner_postgresql_jsonb_query_parameter project_id:, instance_id:, database_id:
  # project_id  = "Your Google Cloud project ID"
  # instance_id = "Your Spanner instance ID"
  # database_id = "Your Spanner database ID"
  spanner = Google::Cloud::Spanner.new project: project_id
  client  = spanner.client instance_id, database_id

  sql_query = <<~QUERY
    SELECT venueid, venuedetails
    FROM Venues
    WHERE CAST(venuedetails ->> 'rating' AS INTEGER) > $1
  QUERY

  # pass parameterized query's params represented by position
  results = client.execute sql_query, params: { p1: 5 }
  puts results.rows.first

  # Read JSONB value from table
  results = client.read "Venues", [:VenueId, :VenueDetails], keys: 19
  puts results.rows.first
end

不支持的 PostgreSQL JSONB 功能

Spanner JSONB 不支持以下 PostgreSQL JSONB 功能：

排序、比较和聚合
PrimaryKey 和 ForeignKey
编入索引，包括 GIN 索引。如需了解详情，请参阅编入索引。
将 JSONB 列转换为任何其他数据类型或从其更改为其他数据类型
在以下工具中使用带非类型化 JSONB 参数的参数化查询 PostgreSQL 线路协议
查询引擎中的强制转换。与标准 PostgreSQL 不同，从 JSONB 强制转换转换为文本格式。只有有效的 JSON 字符串才能强制转换为 JSONB 类型匹配函数签名。示例：
```
    SELECT concat('abc'::text,  '{"key1":1}'::jsonb);  -- Returns error
    SELECT concat('abc'::text, CAST('{"key1":1}'::jsonb AS TEXT));  -- This works
```

编制索引

JSONB 列不支持编入索引。不过，您可以在以下位置创建索引：生成的列，用于从 JSONB 列中提取标量值。

CREATE TABLE Venues (
VenueId   BIGINT PRIMARY KEY,
VenueName  VARCHAR(1024),
VenueAddress VARCHAR(1024),
VenueFeatures JSONB,
TotalCapacity BIGINT GENERATED ALWAYS AS ((VenueFeatures->>'capacity')::BIGINT) STORED,
DateOpened  TIMESTAMPTZ
);

CREATE INDEX VenuesByCapacity ON Venues(TotalCapacity);