Read using a conditional filter

Creates a composite filter using a conditional.

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

Code sample

C++

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
  cbt::Filter filter = cbt::Filter::Condition(
      cbt::Filter::Chain(cbt::Filter::ValueRegex("true"),
                         cbt::Filter::ColumnRegex("data_plan_10gb")),
      cbt::Filter::ApplyLabelTransformer("passed-filter"),
      cbt::Filter::ApplyLabelTransformer("filtered-out"));
  // Read and print the rows.
  for (StatusOr<cbt::Row>& row :
       table.ReadRows(cbt::RowSet(cbt::RowRange::InfiniteRange()), filter)) {
    if (!row) throw std::move(row).status();
    std::cout << row->row_key() << " = ";
    for (auto const& cell : row->cells()) {
      std::cout << "[" << cell.family_name() << ", "
                << cell.column_qualifier() << ", " << cell.value()
                << ", label(";
      for (auto const& label : cell.labels()) {
        std::cout << label << ",";
      }
      std::cout << ")],";
    }
    std::cout << "\n";
  }
}

C#

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

/// <summary>
/// /// Read using a conditional filter from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>

public string filterComposingCondition(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
    // A filter that applies the label passed-filter IF the cell has the column qualifier
    // data_plan_10gb AND the value true, OTHERWISE applies the label filtered-out
    RowFilter filter = RowFilters.Condition(
        RowFilters.Chain(RowFilters.ColumnQualifierExact("data_plan_10gb"), RowFilters.ValueExact("true")),
        new RowFilter { ApplyLabelTransformer = "passed-filter" },
        new RowFilter { ApplyLabelTransformer = "filtered-out" }
        );
    return readFilter(projectId, instanceId, tableId, filter);
}

Go

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

func filterComposingCondition(w io.Writer, projectID, instanceID string, tableName string) error {
	filter := bigtable.ConditionFilter(
		bigtable.ChainFilters(bigtable.ColumnFilter("data_plan_10gb"), bigtable.ValueFilter("true")),
		bigtable.StripValueFilter(),
		bigtable.PassAllFilter())
	return readWithFilter(w, projectID, instanceID, tableName, filter)
}

Java

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

public static void filterComposingCondition() {
  // TODO(developer): Replace these variables before running the sample.
  String projectId = "my-project-id";
  String instanceId = "my-instance-id";
  String tableId = "mobile-time-series";
  filterComposingCondition(projectId, instanceId, tableId);
}

public static void filterComposingCondition(String projectId, String instanceId, String tableId) {
  // A filter that applies the label passed-filter IF the cell has the column qualifier
  // data_plan_10gb AND the value true, OTHERWISE applies the label filtered-out
  Filter filter =
      FILTERS
          .condition(
              FILTERS
                  .chain()
                  .filter(FILTERS.qualifier().exactMatch("data_plan_10gb"))
                  .filter(FILTERS.value().exactMatch("true")))
          .then(FILTERS.label("passed-filter"))
          .otherwise(FILTERS.label("filtered-out"));
  readFilter(projectId, instanceId, tableId, filter);
}

Node.js

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

const filter = {
  condition: {
    test: [
      {column: 'data_plan_10gb'},
      {
        value: 'true',
      },
    ],
    pass: {
      label: 'passed-filter',
    },
    fail: {
      label: 'filtered-out',
    },
  },
};
readWithFilter(filter);

PHP

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

use Google\Cloud\Bigtable\BigtableClient;
use Google\Cloud\Bigtable\Filter;

/**
 * Create a composite filter using a conditional
 *
 * @param string $projectId The Google Cloud project ID
 * @param string $instanceId The ID of the Bigtable instance
 * @param string $tableId The ID of the table to read from
 */
function filter_composing_condition(
    string $projectId,
    string $instanceId,
    string $tableId
): void {
    // Connect to an existing table with an existing instance.
    $dataClient = new BigtableClient([
        'projectId' => $projectId,
    ]);
    $table = $dataClient->table($instanceId, $tableId);

    $filter = Filter::condition(
        Filter::chain()
            ->addFilter(Filter::value()->exactMatch('1'))
            ->addFilter(Filter::qualifier()->exactMatch('data_plan_10gb'))
    )
        ->then(Filter::label('passed-filter'))
        ->otherwise(Filter::label('filtered-out'));

    $rows = $table->readRows([
        'filter' => $filter
    ]);

    foreach ($rows as $key => $row) {
        // The "print_row" helper function is defined in https://cloud.google.com/bigtable/docs/samples/bigtable-reads-print
        print_row($key, $row);
    }
}

Python

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

def filter_composing_condition(project_id, instance_id, table_id):
    client = bigtable.Client(project=project_id, admin=True)
    instance = client.instance(instance_id)
    table = instance.table(table_id)

    rows = table.read_rows(
        filter_=row_filters.ConditionalRowFilter(
            base_filter=row_filters.RowFilterChain(
                filters=[
                    row_filters.ColumnQualifierRegexFilter("data_plan_10gb"),
                    row_filters.ValueRegexFilter("true"),
                ]
            ),
            true_filter=row_filters.ApplyLabelFilter(label="passed-filter"),
            false_filter=row_filters.ApplyLabelFilter(label="filtered-out"),
        )
    )
    for row in rows:
        print_row(row)

Ruby

To learn how to install and use the client library for Bigtable, see Bigtable client libraries.

To authenticate to Bigtable, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

# instance_id = "my-instance"
# table_id    = "my-table"
filter = Google::Cloud::Bigtable::RowFilter.condition(
  Google::Cloud::Bigtable::RowFilter.chain.qualifier("data_plan_10gb").value("true")
)
                                           .on_match(Google::Cloud::Bigtable::RowFilter.label("passed-filter"))
                                           .otherwise(Google::Cloud::Bigtable::RowFilter.label("filtered-out"))
read_with_filter instance_id, table_id, filter

What's next

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