导出全部或部分实体的副本

将 Datastore 中全部或部分实体的副本导出到其他存储系统（例如 Cloud Storage）。

代码示例

C#

如需了解如何安装和使用适用于 Datastore 模式的客户端库，请参阅 Datastore 模式客户端库。 有关详情，请参阅 Datastore 模式 C# API 参考文档。

如需向 Datastore 模式进行身份验证，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.Datastore.Admin.V1;
using System;
using System.Collections.Generic;

public class ExportEntitiesSample
{
    public string ExportEntities(
        string projectId = "your-project-id",
        string outputUrlPrefix = "gs://your-bucket-name",
        string kind = "Task",
        string namespaceId = "default")
    {
        // Create client
        DatastoreAdminClient datastoreAdminClient = DatastoreAdminClient.Create();

        IDictionary<string, string> labels = new Dictionary<string, string> { { "cloud_datastore_samples", "true" }, };
        EntityFilter entityFilter = new EntityFilter
        {
            Kinds = { kind },
            NamespaceIds = { namespaceId }
        };

        var response = datastoreAdminClient.ExportEntities(projectId, labels, entityFilter, outputUrlPrefix);

        // Poll until the returned long-running operation is complete
        var completedResponse = response.PollUntilCompleted();

        if (completedResponse.IsFaulted)
        {
            Console.WriteLine($"Error while Exporting Entities: {completedResponse.Exception}");
            throw completedResponse.Exception;
        }

        Console.WriteLine($"Entities exported successfully.");

        ExportEntitiesResponse result = completedResponse.Result;

        return result.OutputUrl;
    }
}

Go

如需了解如何安装和使用适用于 Datastore 模式的客户端库，请参阅 Datastore 模式客户端库。 有关详情，请参阅 Datastore 模式 Go API 参考文档。

如需向 Datastore 模式进行身份验证，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"

	admin "cloud.google.com/go/datastore/admin/apiv1"
	"cloud.google.com/go/datastore/admin/apiv1/adminpb"
)

// entitiesExport exports a copy of all or a subset of entities from
// Datastore to another storage system, such as Cloud Storage.
func entitiesExport(w io.Writer, projectID, outputURLPrefix string) (*adminpb.ExportEntitiesResponse, error) {
	// projectID := "project-id"
	// outputURLPrefix := "gs://bucket-name"
	ctx := context.Background()
	client, err := admin.NewDatastoreAdminClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("admin.NewDatastoreAdminClient: %w", err)
	}
	defer client.Close()

	req := &adminpb.ExportEntitiesRequest{
		ProjectId:       projectID,
		OutputUrlPrefix: outputURLPrefix,
	}
	op, err := client.ExportEntities(ctx, req)
	if err != nil {
		return nil, fmt.Errorf("ExportEntities: %w", err)
	}
	resp, err := op.Wait(ctx)
	if err != nil {
		return nil, fmt.Errorf("Wait: %w", err)
	}
	fmt.Fprintln(w, "Entities were exported")
	return resp, nil
}

Node.js

如需了解如何安装和使用适用于 Datastore 模式的客户端库，请参阅 Datastore 模式客户端库。 有关详情，请参阅 Datastore 模式 Node.js API 参考文档。

如需向 Datastore 模式进行身份验证，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。

const {Datastore} = require('@google-cloud/datastore');
const datastore = new Datastore();

async function exportEntities() {
  /**
   * TODO(developer): Uncomment these variables before running the sample.
   */
  // const bucket = 'YOUR_BUCKET_NAME';

  const [exportOperation] = await datastore.export({bucket});
  await exportOperation.promise();

  // The export operation has created a new file in your bucket, e.g.
  // gs://{YOUR_BUCKET_NAME}/{timestamp}/{timestamp}.overall_export.metadata
  console.log(`Export file created: ${exportOperation.result.outputUrl}`);

  // You may also choose to include only specific kinds and namespaces.
  const [specificExportOperation] = await datastore.export({
    bucket,
    kinds: ['Employee', 'Task'],
    namespaces: ['Company'],
  });
  await specificExportOperation.promise();
  console.log(specificExportOperation.result.outputUrl);
}

exportEntities();

Python

如需了解如何安装和使用适用于 Datastore 模式的客户端库，请参阅 Datastore 模式客户端库。 有关详情，请参阅 Datastore 模式 Python API 参考文档。

如需向 Datastore 模式进行身份验证，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 export_entities(project_id, output_url_prefix):
    """
    Exports a copy of all or a subset of entities from
    Datastore to another storage system, such as Cloud Storage.
    """
    # project_id = "project-id"
    # output_url_prefix = "gs://bucket-name"
    client = DatastoreAdminClient()

    op = client.export_entities(
        {"project_id": project_id, "output_url_prefix": output_url_prefix}
    )
    response = op.result(timeout=300)

    print("Entities were exported\n")
    return response

Ruby

如需了解如何安装和使用适用于 Datastore 模式的客户端库，请参阅 Datastore 模式客户端库。 有关详情，请参阅 Datastore 模式 Ruby API 参考文档。

如需向 Datastore 模式进行身份验证，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。

# project_id = "project-id"
# output_url_prefix = "gs://bucket-name"
op = client.export_entities project_id: project_id, output_url_prefix: output_url_prefix

op.wait_until_done!
raise op.error.message if op.error?

response = op.response
# Process the response.

metadata = op.metadata
# Process the metadata.

puts "Entities were exported"

后续步骤

如需搜索和过滤其他 Google Cloud 产品的代码示例，请参阅 Google Cloud 示例浏览器。