Get write stream details

Retrieves information about an existing BigQuery write stream. Use this to check the state and schema of a stream before appending data.

Code sample

Node.js

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

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

const {BigQueryWriteClient} = require('@google-cloud/bigquery-storage');
const {status} = require('@grpc/grpc-js');

const client = new BigQueryWriteClient();

/**
 * Gets information about a single write stream.
 *
 * @param {string} projectId The project ID of the table. e.g. 'my-project'
 * @param {string} datasetId The dataset ID of the table. e.g. 'my_dataset'
 * @param {string} tableId The ID of the table. e.g. 'my_table'
 */
async function getWriteStream(projectId, datasetId, tableId) {

  const streamId = "_default";
  const name = client.writeStreamPath(projectId, datasetId, tableId, streamId);

  const request = {
    name,
  };

  try {
    const [response] = await client.getWriteStream(request);

    console.log(`Got write stream: ${response.name}`);
    console.log(`Stream type: ${response.type}`);
    console.log(`Stream location: ${response.location}`);
  } catch (err) {
    if (err.code === status.NOT_FOUND) {
      console.log(`Write stream ${name} not found.`);
    } else {
      console.error('Error getting write stream:', err);
    }
  }
}

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.

import google.api_core.exceptions
from google.cloud import bigquery_storage_v1


def get_write_stream(
    project_id: str, dataset_id: str, table_id: str, stream_id: str
) -> None:
    """Gets information about a single write stream.

    Args:
        project_id: The project id.
        dataset_id: The dataset id
        table_id: The table id
        stream_id: The stream id
    """
    client = bigquery_storage_v1.BigQueryWriteClient()
    stream_name = (
        f"projects/{project_id}/datasets/{dataset_id}"
        f"/tables/{table_id}/streams/{stream_id}"
    )

    try:
        stream = client.get_write_stream(name=stream_name)

        print(f"Got write stream: {stream.name}")
        print(f"Stream type: {stream.Type(stream.type_).name}")

    except google.api_core.exceptions.NotFound:
        print(f"Write stream not found: {stream_name}")

What's next

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