Change the user attached to a transfer configuration.

## Explore further


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

- [Manage transfers](https://docs.cloud.google.com/bigquery/docs/working-with-transfers)
- [Scheduling queries](https://docs.cloud.google.com/bigquery/docs/scheduling-queries)
- [Use service accounts with BigQuery Data Transfer Service](https://docs.cloud.google.com/bigquery/docs/use-service-accounts)

## Code sample

### Java


Before trying this sample, follow the Java setup instructions in the
[BigQuery quickstart using
client libraries](https://docs.cloud.google.com/bigquery/docs/quickstarts/quickstart-client-libraries).


For more information, see the
[BigQuery Java API
reference documentation](https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/overview).


To authenticate to BigQuery, set up Application Default Credentials.
For more information, see

[Set up authentication for client libraries](https://docs.cloud.google.com/bigquery/docs/authentication#client-libs).

    import com.google.api.gax.rpc.https://docs.cloud.google.com/java/docs/reference/gax/latest/com.google.api.gax.rpc.ApiException.html;
    import com.google.cloud.bigquery.datatransfer.v1.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.DataTransferServiceClient.html;
    import com.google.cloud.bigquery.datatransfer.v1.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.TransferConfig.html;
    import com.google.cloud.bigquery.datatransfer.v1.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.UpdateTransferConfigRequest.html;
    import com.google.protobuf.https://docs.cloud.google.com/java/docs/reference/protobuf/latest/com.google.protobuf.FieldMask.html;
    import com.google.protobuf.util.https://docs.cloud.google.com/java/docs/reference/protobuf/latest/com.google.protobuf.util.FieldMaskUtil.html;
    import java.io.IOException;

    // Sample to update credentials in transfer config.
    public class UpdateCredentials {

      public static void main(String[] args) throws IOException {
        // TODO(developer): Replace these variables before running the sample.
        String configId = "MY_CONFIG_ID";
        String serviceAccount = "MY_SERVICE_ACCOUNT";
        https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.TransferConfig.html transferConfig = https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.TransferConfig.html.newBuilder().setName(configId).build();
        https://docs.cloud.google.com/java/docs/reference/protobuf/latest/com.google.protobuf.FieldMask.html updateMask = https://docs.cloud.google.com/java/docs/reference/protobuf/latest/com.google.protobuf.util.FieldMaskUtil.html.fromString("service_account_name");
        updateCredentials(transferConfig, serviceAccount, updateMask);
      }

      public static void updateCredentials(
          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.TransferConfig.html transferConfig, String serviceAccount, https://docs.cloud.google.com/java/docs/reference/protobuf/latest/com.google.protobuf.FieldMask.html updateMask)
          throws IOException {
        try (https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.DataTransferServiceClient.html dataTransferServiceClient = https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.DataTransferServiceClient.html.create()) {
          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.UpdateTransferConfigRequest.html request =
              https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.UpdateTransferConfigRequest.html.newBuilder()
                  .setTransferConfig(transferConfig)
                  .https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquerydatatransfer/latest/com.google.cloud.bigquery.datatransfer.v1.UpdateTransferConfigRequest.Builder.html#com_google_cloud_bigquery_datatransfer_v1_UpdateTransferConfigRequest_Builder_setUpdateMask_com_google_protobuf_FieldMask_(updateMask)
                  .setServiceAccountName(serviceAccount)
                  .build();
          dataTransferServiceClient.updateTransferConfig(request);
          System.out.println("Credentials updated successfully");
        } catch (https://docs.cloud.google.com/java/docs/reference/gax/latest/com.google.api.gax.rpc.ApiException.html ex) {
          System.out.print("Credentials was not updated." + ex.toString());
        }
      }
    }

### Python


Before trying this sample, follow the Python setup instructions in the
[BigQuery quickstart using
client libraries](https://docs.cloud.google.com/bigquery/docs/quickstarts/quickstart-client-libraries).


For more information, see the
[BigQuery Python API
reference documentation](https://docs.cloud.google.com/python/docs/reference/bigquery/latest).


To authenticate to BigQuery, set up Application Default Credentials.
For more information, see

[Set up authentication for client libraries](https://docs.cloud.google.com/bigquery/docs/authentication#client-libs).

    from google.cloud import bigquery_datatransfer
    from google.protobuf import field_mask_pb2

    transfer_client = bigquery_datatransfer.https://docs.cloud.google.com/python/docs/reference/bigquerydatatransfer/latest/google.cloud.bigquery_datatransfer_v1.services.data_transfer_service.DataTransferServiceClient.html()

    service_account_name = "abcdef-test-sa@abcdef-test.iam.gserviceaccount.com"
    transfer_config_name = "projects/1234/locations/us/transferConfigs/abcd"

    transfer_config = bigquery_datatransfer.https://docs.cloud.google.com/python/docs/reference/bigquerydatatransfer/latest/google.cloud.bigquery_datatransfer_v1.types.TransferConfig.html(name=transfer_config_name)

    transfer_config = transfer_client.https://docs.cloud.google.com/python/docs/reference/bigquerydatatransfer/latest/google.cloud.bigquery_datatransfer_v1.services.data_transfer_service.DataTransferServiceClient.html#google_cloud_bigquery_datatransfer_v1_services_data_transfer_service_DataTransferServiceClient_update_transfer_config(
        {
            "transfer_config": transfer_config,
            "update_mask": field_mask_pb2.FieldMask(paths=["service_account_name"]),
            "service_account_name": service_account_name,
        }
    )

    print("Updated config: '{}'".format(transfer_config.name))

## What's next


To search and filter code samples for other Google Cloud products, see the
[Google Cloud sample browser](https://docs.cloud.google.com/docs/samples?product=bigquerydatatransferservice).