Create a scheduled query

Schedule a query to run every 24 hours with a destination table identifier based on the run date.

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

Code sample

Go

Before trying this sample, follow the Go setup instructions in the BigQuery quickstart using client libraries. For more information, see the BigQuery Go API reference documentation.

To authenticate to BigQuery, set up Application Default Credentials. For more information, see Set up authentication for client libraries. 

import (
	"context"
	"fmt"

	"cloud.google.com/go/bigquery"
	datatransfer "cloud.google.com/go/bigquery/datatransfer/apiv1"
	"cloud.google.com/go/bigquery/datatransfer/apiv1/datatransferpb"
	"google.golang.org/protobuf/types/known/structpb"
)

// createScheduledQuery schedule a query to run every
// 24 hours with a destination table identifier based on the run date.
func createScheduledQuery(projectID, datasetID, query string) error {
	// projectID := "my-project-id"
	// datasetID := "my-dataset-id"
	// query = `SELECT CURRENT_TIMESTAMP() as current_time, @run_time as intended_run_time,
	// @run_date as intended_run_date, 17 as some_integer`
	ctx := context.Background()
	dtc, err := datatransfer.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("datatransfer.NewClient: %w", err)
	}
	defer dtc.Close()

	paramsMap := map[string]interface{}{}
	paramsMap["destination_table_name_template"] = "my_destination_table_{run_date}"
	paramsMap["write_disposition"] = string(bigquery.WriteTruncate)
	paramsMap["partitioning_field"] = ""
	paramsMap["query"] = query
	params, err := structpb.NewStruct(paramsMap)
	if err != nil {
		return fmt.Errorf("structpb.NewStruct: %w", err)
	}

	req := &datatransferpb.CreateTransferConfigRequest{
		Parent: fmt.Sprintf("projects/%s", projectID),
		TransferConfig: &datatransferpb.TransferConfig{
			Destination: &datatransferpb.TransferConfig_DestinationDatasetId{
				DestinationDatasetId: datasetID,
			},
			DisplayName:  "Your Scheduled Query Name",
			DataSourceId: "scheduled_query",
			Params:       params,
			Schedule:     "every 24 hours",
		},
	}

	_, err = dtc.CreateTransferConfig(ctx, req)
	if err != nil {
		return fmt.Errorf("dtc.CreateTransferConfig: %w", err)
	}

	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the BigQuery quickstart using client libraries. For more information, see the BigQuery Java API reference documentation.

To authenticate to BigQuery, set up Application Default Credentials. For more information, see Set up authentication for client libraries. 

import com.google.api.gax.rpc.ApiException;
import com.google.cloud.bigquery.datatransfer.v1.CreateTransferConfigRequest;
import com.google.cloud.bigquery.datatransfer.v1.DataTransferServiceClient;
import com.google.cloud.bigquery.datatransfer.v1.ProjectName;
import com.google.cloud.bigquery.datatransfer.v1.TransferConfig;
import com.google.protobuf.Struct;
import com.google.protobuf.Value;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

// Sample to create a scheduled query
public class CreateScheduledQuery {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    final String projectId = "MY_PROJECT_ID";
    final String datasetId = "MY_DATASET_ID";
    final String query =
        "SELECT CURRENT_TIMESTAMP() as current_time, @run_time as intended_run_time, "
            + "@run_date as intended_run_date, 17 as some_integer";
    Map<String, Value> params = new HashMap<>();
    params.put("query", Value.newBuilder().setStringValue(query).build());
    params.put(
        "destination_table_name_template",
        Value.newBuilder().setStringValue("my_destination_table_{run_date}").build());
    params.put("write_disposition", Value.newBuilder().setStringValue("WRITE_TRUNCATE").build());
    params.put("partitioning_field", Value.newBuilder().build());
    TransferConfig transferConfig =
        TransferConfig.newBuilder()
            .setDestinationDatasetId(datasetId)
            .setDisplayName("Your Scheduled Query Name")
            .setDataSourceId("scheduled_query")
            .setParams(Struct.newBuilder().putAllFields(params).build())
            .setSchedule("every 24 hours")
            .build();
    createScheduledQuery(projectId, transferConfig);
  }

  public static void createScheduledQuery(String projectId, TransferConfig transferConfig)
      throws IOException {
    try (DataTransferServiceClient dataTransferServiceClient = DataTransferServiceClient.create()) {
      ProjectName parent = ProjectName.of(projectId);
      CreateTransferConfigRequest request =
          CreateTransferConfigRequest.newBuilder()
              .setParent(parent.toString())
              .setTransferConfig(transferConfig)
              .build();
      TransferConfig config = dataTransferServiceClient.createTransferConfig(request);
      System.out.println("\nScheduled query created successfully :" + config.getName());
    } catch (ApiException ex) {
      System.out.print("\nScheduled query was not created." + ex.toString());
    }
  }
}

Python

Before trying this sample, follow the Python setup instructions in the BigQuery quickstart using client libraries. For more information, see the BigQuery Python API reference documentation.

To authenticate to BigQuery, set up Application Default Credentials. For more information, see Set up authentication for client libraries. 

from google.cloud import bigquery_datatransfer

transfer_client = bigquery_datatransfer.DataTransferServiceClient()

# The project where the query job runs is the same as the project
# containing the destination dataset.
project_id = "your-project-id"
dataset_id = "your_dataset_id"

# This service account will be used to execute the scheduled queries. Omit
# this request parameter to run the query as the user with the credentials
# associated with this client.
service_account_name = "abcdef-test-sa@abcdef-test.iam.gserviceaccount.com"

# Use standard SQL syntax for the query.
query_string = """
SELECT
  CURRENT_TIMESTAMP() as current_time,
  @run_time as intended_run_time,
  @run_date as intended_run_date,
  17 as some_integer
"""

parent = transfer_client.common_project_path(project_id)

transfer_config = bigquery_datatransfer.TransferConfig(
    destination_dataset_id=dataset_id,
    display_name="Your Scheduled Query Name",
    data_source_id="scheduled_query",
    params={
        "query": query_string,
        "destination_table_name_template": "your_table_{run_date}",
        "write_disposition": "WRITE_TRUNCATE",
        "partitioning_field": "",
    },
    schedule="every 24 hours",
)

transfer_config = transfer_client.create_transfer_config(
    bigquery_datatransfer.CreateTransferConfigRequest(
        parent=parent,
        transfer_config=transfer_config,
        service_account_name=service_account_name,
    )
)

print("Created scheduled query '{}'".format(transfer_config.name))

What's next

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