Demuestra la traducción de consultas por lotes

Usa el servicio de migración de BigQuery para traducir consultas almacenadas en Cloud Storage.

Muestra de código

Go

Antes de probar este ejemplo, sigue las instrucciones de configuración para Go incluidas en la guía de inicio rápido de BigQuery sobre cómo usar bibliotecas cliente. Para obtener más información, consulta la documentación de referencia de la API de BigQuery para Go.

Para autenticarte en BigQuery, configura las credenciales predeterminadas de la aplicación. Si deseas obtener más información, consulta Configura la autenticación para bibliotecas cliente.

// The bigquery_migration_quickstart application demonstrates basic usage of the
// BigQuery migration API by executing a workflow that performs a batch SQL
// translation task.
package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"time"

	migration "cloud.google.com/go/bigquery/migration/apiv2"
	"cloud.google.com/go/bigquery/migration/apiv2/migrationpb"
)

func main() {
	// Define command line flags for controlling the behavior of this quickstart.
	projectID := flag.String("project_id", "", "Cloud Project ID.")
	location := flag.String("location", "us", "BigQuery Migration location used for interactions.")
	outputPath := flag.String("output", "", "Cloud Storage path for translated resources.")
	// Parse flags and do some minimal validation.
	flag.Parse()
	if *projectID == "" {
		log.Fatal("empty --project_id specified, please provide a valid project ID")
	}
	if *location == "" {
		log.Fatal("empty --location specified, please provide a valid location")
	}
	if *outputPath == "" {
		log.Fatalf("empty --output specified, please provide a valid cloud storage path")
	}

	ctx := context.Background()
	migClient, err := migration.NewClient(ctx)
	if err != nil {
		log.Fatalf("migration.NewClient: %v", err)
	}
	defer migClient.Close()

	workflow, err := executeTranslationWorkflow(ctx, migClient, *projectID, *location, *outputPath)
	if err != nil {
		log.Fatalf("workflow execution failed: %v\n", err)
	}

	reportWorkflowStatus(workflow)
}

// executeTranslationWorkflow constructs a migration workflow that performs batch SQL translation.
func executeTranslationWorkflow(ctx context.Context, client *migration.Client, projectID, location, outPath string) (*migrationpb.MigrationWorkflow, error) {

	// Construct the workflow creation request.  In this workflow, we have only a single translation task present.
	req := &migrationpb.CreateMigrationWorkflowRequest{
		Parent: fmt.Sprintf("projects/%s/locations/%s", projectID, location),
		MigrationWorkflow: &migrationpb.MigrationWorkflow{
			DisplayName: "example SQL conversion",
			Tasks: map[string]*migrationpb.MigrationTask{
				"example_conversion": {
					Type: "Translation_Teradata2BQ",
					TaskDetails: &migrationpb.MigrationTask_TranslationConfigDetails{
						TranslationConfigDetails: &migrationpb.TranslationConfigDetails{
							SourceLocation: &migrationpb.TranslationConfigDetails_GcsSourcePath{
								GcsSourcePath: "gs://cloud-samples-data/bigquery/migration/translation/input/",
							},
							TargetLocation: &migrationpb.TranslationConfigDetails_GcsTargetPath{
								GcsTargetPath: outPath,
							},
							SourceDialect: &migrationpb.Dialect{
								DialectValue: &migrationpb.Dialect_TeradataDialect{
									TeradataDialect: &migrationpb.TeradataDialect{
										Mode: migrationpb.TeradataDialect_SQL,
									},
								},
							},
							TargetDialect: &migrationpb.Dialect{
								DialectValue: &migrationpb.Dialect_BigqueryDialect{},
							},
						},
					},
				},
			},
		},
	}

	// Create the workflow using the request.
	workflow, err := client.CreateMigrationWorkflow(ctx, req)
	if err != nil {
		return nil, fmt.Errorf("CreateMigrationWorkflow: %w", err)
	}
	fmt.Printf("workflow created: %s", workflow.GetName())

	// This is an asyncronous process, so we now poll the workflow
	// until completion or a suitable timeout has elapsed.
	timeoutCtx, cancel := context.WithTimeout(ctx, 5*time.Minute)
	defer cancel()
	for {
		select {
		case <-timeoutCtx.Done():
			return nil, fmt.Errorf("task %s didn't complete due to context expiring", workflow.GetName())
		default:
			polledWorkflow, err := client.GetMigrationWorkflow(timeoutCtx, &migrationpb.GetMigrationWorkflowRequest{
				Name: workflow.GetName(),
			})
			if err != nil {
				return nil, fmt.Errorf("polling ended in error: %w", err)
			}
			if polledWorkflow.GetState() == migrationpb.MigrationWorkflow_COMPLETED {
				// polledWorkflow contains the most recent metadata about the workflow, so we return that.
				return polledWorkflow, nil
			}
			// workflow still isn't complete, so sleep briefly before polling again.
			time.Sleep(5 * time.Second)
		}
	}
}

// reportWorkflowStatus prints information about the workflow execution in a more human readable format.
func reportWorkflowStatus(workflow *migrationpb.MigrationWorkflow) {
	fmt.Printf("Migration workflow %s ended in state %s.\n", workflow.GetName(), workflow.GetState().String())
	for k, task := range workflow.GetTasks() {
		fmt.Printf(" - Task %s had id %s", k, task.GetId())
		if task.GetProcessingError() != nil {
			fmt.Printf(" with processing error: %s", task.GetProcessingError().GetReason())
		}
		fmt.Println()
	}
}

¿Qué sigue?

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