Update a routine

import (
	"context"
	"fmt"

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

// updateRoutine demonstrates updating an existing BigQuery UDF using the routine API.
func updateRoutine(projectID, datasetID, routineID string) error {
	// projectID := "my-project-id"
	// datasetID := "mydatasetid"
	// routineID := "myroutineid"
	ctx := context.Background()

	client, err := bigquery.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("bigquery.NewClient: %w", err)
	}
	defer client.Close()

	routineRef := client.Dataset(datasetID).Routine(routineID)

	// fetch existing metadata
	meta, err := routineRef.Metadata(ctx)
	if err != nil {
		return fmt.Errorf("couldn't retrieve metadata: %w", err)
	}

	// Due to a limitation in the backend, supply all the properties for update.
	update := &bigquery.RoutineMetadataToUpdate{
		Type:        meta.Type,
		Language:    meta.Language,
		Arguments:   meta.Arguments,
		Description: meta.Description,
		ReturnType:  meta.ReturnType,
		Body:        "x * 4",
	}

	if _, err := routineRef.Update(ctx, update, meta.ETag); err != nil {
		return fmt.Errorf("update failed: %w", err)
	}

	return nil
}

import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.Routine;
import com.google.cloud.bigquery.RoutineId;

// Sample to update routine
public class UpdateRoutine {

  public static void main(String[] args) {
    // TODO(developer): Replace these variables before running the sample.
    String datasetName = "MY_DATASET_NAME";
    String routineName = "MY_ROUTINE_NAME";
    updateRoutine(datasetName, routineName);
  }

  public static void updateRoutine(String datasetName, String routineName) {
    try {
      // Initialize client that will be used to send requests. This client only needs to be created
      // once, and can be reused for multiple requests.
      BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();

      Routine routine = bigquery.getRoutine(RoutineId.of(datasetName, routineName));
      routine.toBuilder().setBody("x * 4").build().update();
      System.out.println("Routine updated successfully");
    } catch (BigQueryException e) {
      System.out.println("Routine was not updated. \n" + e.toString());
    }
  }
}