Lists all existing datasets in a project.

## Explore further


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

- [List datasets](https://docs.cloud.google.com/bigquery/docs/listing-datasets)

## Code sample

### C#


Before trying this sample, follow the C# 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 C# API
reference documentation](https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.V2/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).


    using https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.V2/latest/Google.Cloud.BigQuery.V2.html;
    using System;
    using System.Collections.Generic;
    using System.Linq;

    public class BigQueryListDatasets
    {
        public void ListDatasets(
            string projectId = "your-project-id"
        )
        {
            https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.V2/latest/Google.Cloud.BigQuery.V2.BigQueryClient.html client = https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.V2/latest/Google.Cloud.BigQuery.V2.BigQueryClient.html.https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.V2/latest/Google.Cloud.BigQuery.V2.BigQueryClient.html#Google_Cloud_BigQuery_V2_BigQueryClient_Create_System_String_Google_Apis_Auth_OAuth2_GoogleCredential_(projectId);
            // Retrieve list of datasets in project
            List<BigQueryDataset> datasets = client.https://docs.cloud.google.com/dotnet/docs/reference/Google.Cloud.BigQuery.V2/latest/Google.Cloud.BigQuery.V2.BigQueryClient.html#Google_Cloud_BigQuery_V2_BigQueryClient_ListDatasets_Google_Apis_Bigquery_v2_Data_ProjectReference_Google_Cloud_BigQuery_V2_ListDatasetsOptions_().ToList();
            // Display the results
            if (datasets.Count > 0)
            {
                Console.WriteLine($"Datasets in project {projectId}:");
                foreach (var dataset in datasets)
                {
                    Console.WriteLine($"\t{dataset.Reference.DatasetId}");
                }
            }
            else
            {
                Console.WriteLine($"{projectId} does not contain any datasets.");
            }
        }
    }

### Go


Before trying this sample, follow the Go 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 Go API
reference documentation](https://godoc.org/cloud.google.com/go/bigquery).


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 (
    	"context"
    	"fmt"
    	"io"

    	"cloud.google.com/go/bigquery"
    	"google.golang.org/api/iterator"
    )

    // listDatasets demonstrates iterating through the collection of datasets in a project.
    func listDatasets(projectID string, w io.Writer) error {
    	// projectID := "my-project-id"
    	ctx := context.Background()
    	client, err := bigquery.NewClient(ctx, projectID)
    	if err != nil {
    		return fmt.Errorf("bigquery.NewClient: %w", err)
    	}
    	defer client.Close()

    	it := client.https://docs.cloud.google.com/go/docs/reference/cloud.google.com/go/bigquery/latest/index.html#cloud_google_com_go_bigquery_Client_Datasets(ctx)
    	for {
    		dataset, err := it.Next()
    		if err == iterator.Done {
    			break
    		}
    		if err != nil {
    			return err
    		}
    		fmt.Fprintln(w, dataset.DatasetID)
    	}
    	return nil
    }

### 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.paging.https://docs.cloud.google.com/java/docs/reference/gax/latest/com.google.api.gax.paging.Page.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQuery.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQuery.html.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQuery.DatasetListOption.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQueryException.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQueryOptions.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.Dataset.html;

    public class ListDatasets {

      public static void main(String[] args) {
        // TODO(developer): Replace these variables before running the sample.
        String projectId = "MY_PROJECT_ID";
        listDatasets(projectId);
      }

      public static void listDatasets(String projectId) {
        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.
          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQuery.html bigquery = https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQueryOptions.html.getDefaultInstance().getService();

          Page<Dataset> datasets = bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQuery.html#com_google_cloud_bigquery_BigQuery_listDatasets_com_google_cloud_bigquery_BigQuery_DatasetListOption____(projectId, DatasetListOption.pageSize(100));
          if (datasets == null) {
            System.out.println("Dataset does not contain any models");
            return;
          }
          datasets
              .iterateAll()
              .forEach(
                  dataset -> System.out.printf("Success! Dataset ID: %s ", dataset.getDatasetId()));
        } catch (https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQueryException.html e) {
          System.out.println("Project does not contain any datasets \n" + e.toString());
        }
      }
    }

### PHP


Before trying this sample, follow the PHP 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 PHP API
reference documentation](https://docs.cloud.google.com/php/docs/reference/cloud-bigquery/latest/BigQueryClient).


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).

    use Google\Cloud\BigQuery\BigQueryClient;

    /**
     * List all datasets in the given project
     *
     * @param string $projectId The project Id of your Google Cloud Project.
     */
    function list_datasets(string $projectId): void
    {
        $bigQuery = new BigQueryClient([
          'projectId' => $projectId,
        ]);
        $datasets = $bigQuery->datasets();
        foreach ($datasets as $dataset) {
            print($dataset->id() . PHP_EOL);
        }
    }

### 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 https://docs.cloud.google.com/python/docs/reference/bigquery/latest

    # Construct a BigQuery client object.
    client = https://docs.cloud.google.com/python/docs/reference/bigquery/latest.https://docs.cloud.google.com/python/docs/reference/bigquery/latest/google.cloud.bigquery.client.Client.html()

    datasets = list(client.https://docs.cloud.google.com/python/docs/reference/bigquery/latest/google.cloud.bigquery.client.Client.html#google_cloud_bigquery_client_Client_list_datasets())  # Make an API request.
    project = client.project

    if datasets:
        print("Datasets in project {}:".format(project))
        for dataset in datasets:
            print("\t{}".format(dataset.dataset_id))
    else:
        print("{} project does not contain any datasets.".format(project))

### Ruby


Before trying this sample, follow the Ruby 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 Ruby API
reference documentation](https://googleapis.dev/ruby/google-cloud-bigquery/latest/Google/Cloud/Bigquery.html).


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).

    require "google/cloud/bigquery"

    def list_datasets project_id = "your-project-id"
      bigquery = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigquery-migration/latest/Google-Cloud-Bigquery.html.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigquery/latest/Google-Cloud-Bigquery.html project: project_id

      puts "Datasets in project #{project_id}:"
      bigquery.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigquery/latest/Google-Cloud-Bigquery-Project.html.each do |dataset|
        puts "\t#{dataset.dataset_id}"
      end
    end

## 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=bigquery).