# Read examples
Cloud Bigtable client libraries provide the ability to read data
from a table. This page provides examples of each type of read request in
multiple languages. For an overview, see [Reads](https://docs.cloud.google.com/bigtable/docs/reads).
The Python client library for Bigtable offers two APIs, `asyncio`
and a synchronous API. If your application is asynchronous, use `asyncio`.
## Required roles
To get the permissions that
you need to read data from a table,
ask your administrator to grant you the
[**Bigtable reader**](https://docs.cloud.google.com/iam/docs/roles-permissions/bigtable#bigtable.reader) (`roles/bigtable.reader`) IAM role on the table.
For more information about granting roles, see [Manage access to projects, folders, and organizations](https://docs.cloud.google.com/iam/docs/granting-changing-revoking-access).
You might also be able to get
the required permissions through [custom
roles](https://docs.cloud.google.com/iam/docs/creating-custom-roles) or other [predefined
roles](https://docs.cloud.google.com/iam/docs/roles-overview#predefined).
## Read a single row
The following code samples show how to get a **single row** of data using the
row key.
### Go
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
func readRow(w io.Writer, projectID, instanceID string, tableName string) error {
// projectID := "my-project-id"
// instanceID := "my-instance-id"
// tableName := "mobile-time-series"
ctx := context.Background()
client, err := bigtable.NewClient(ctx, projectID, instanceID)
if err != nil {
return fmt.Errorf("bigtable.NewClient: %w", err)
}
defer client.Close()
tbl := client.Open(tableName)
rowKey := "phone#4c410523#20190501"
row, err := tbl.ReadRow(ctx, rowKey)
if err != nil {
return fmt.Errorf("could not read row with key %s: %w", rowKey, err)
}
printRow(w, row)
return nil
}
### HBase
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
/**
* Example of reading an individual row key.
*/
public static void readRow() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRow(projectId, instanceId, tableId);
}
public static void readRow(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
Table table = connection.getTable(TableName.valueOf(tableId));
byte[] rowkey = Bytes.toBytes("phone#4c410523#20190501");
Result row = table.get(new Get(rowkey));
printRow(row);
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Java
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
public static void readRow() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRow(projectId, instanceId, tableId);
}
public static void readRow(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
String rowkey = "phone#4c410523#20190501";
Row row = dataClient.readRow(TableId.of(tableId), rowkey);
printRow(row);
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Python asyncio
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
from google.cloud.bigtable.data import BigtableDataClientAsync
async def read_row(project_id, instance_id, table_id):
async with BigtableDataClientAsync(project=project_id) as client:
async with client.get_table(instance_id, table_id) as table:
row_key = "phone#4c410523#20190501"
row = await table.read_row(row_key)
print(row)
### Python
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
def read_row(project_id, instance_id, table_id):
from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest
client = https://docs.cloud.google.com/python/docs/reference/bigtable/latest.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html(project=project_id, admin=True)
instance = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html#google_cloud_bigtable_client_Client_instance(instance_id)
table = instance.table(table_id)
row_key = "phone#4c410523#20190501"
row = table.read_row(row_key)
print_row(row)
### C#
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
///
/// /// Reads one row from an existing table.
///
/// Your Google Cloud Project ID.
/// Your Google Cloud Bigtable Instance ID.
/// Your Google Cloud Bigtable table ID.
public string ReadRow(
string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
BigtableClient bigtableClient = BigtableClient.Create();
TableName tableName = new TableName(projectId, instanceId, tableId);
Row row = bigtableClient.ReadRow(tableName, rowKey: "phone#4c410523#20190501");
return PrintRow(row);
}
### C++
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](google::cloud::bigtable::Table table, std::string const& row_key) {
StatusOr> tuple =
table.ReadRow(row_key, cbt::Filter::PassAllFilter());
if (!tuple) throw std::move(tuple).status();
if (!tuple->first) {
std::cout << "Row " << row_key << " not found\n";
return;
}
PrintRow(tuple->second);
}
### Node.js
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
const rowkey = 'phone#4c410523#20190501';
const [row] = await table.row(rowkey).get();
printRow(rowkey, row.data);
### PHP
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
use Google\Cloud\Bigtable\BigtableClient;
/**
* Read a row using the row key
*
* @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 read_row(
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);
$rowkey = 'phone#4c410523#20190501';
$row = $table->readRow($rowkey);
print_row($rowkey, $row);
}
### Ruby
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html
table = bigtable.table instance_id, table_id
row = table.read_row "phone#4c410523#20190501"
print_row row
end
## Read a partial row
The following code samples show how to get **specific columns** from a row.
### Go
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
func readRowPartial(w io.Writer, projectID, instanceID string, tableName string) error {
// projectID := "my-project-id"
// instanceID := "my-instance-id"
// tableName := "mobile-time-series"
ctx := context.Background()
client, err := bigtable.NewClient(ctx, projectID, instanceID)
if err != nil {
return fmt.Errorf("bigtable.NewClient: %w", err)
}
defer client.Close()
tbl := client.Open(tableName)
rowKey := "phone#4c410523#20190501"
row, err := tbl.ReadRow(ctx, rowKey, bigtable.RowFilter(bigtable.ColumnFilter("os_build")))
if err != nil {
return fmt.Errorf("could not read row with key %s: %w", rowKey, err)
}
printRow(w, row)
return nil
}
### HBase
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
/**
* Example of reading a subset of the columns for a single row.
*/
public static void readRowPartial() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRowPartial(projectId, instanceId, tableId);
}
public static void readRowPartial(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
Table table = connection.getTable(TableName.valueOf(tableId));
byte[] rowkey = Bytes.toBytes("phone#4c410523#20190501");
Result row =
table.get(
new Get(rowkey).addColumn(Bytes.toBytes("stats_summary"), Bytes.toBytes("os_build")));
printRow(row);
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Java
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
public static void readRowPartial() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRowPartial(projectId, instanceId, tableId);
}
public static void readRowPartial(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
String rowkey = "phone#4c410523#20190501";
Filters.Filter filter =
FILTERS
.chain()
.filter(FILTERS.family().exactMatch("stats_summary"))
.filter(FILTERS.qualifier().exactMatch("os_build"));
Row row = dataClient.readRow(TableId.of(tableId), rowkey, filter);
printRow(row);
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Python asyncio
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.row_filters.html
async def read_row_partial(project_id, instance_id, table_id):
async with BigtableDataClientAsync(project=project_id) as client:
async with client.get_table(instance_id, table_id) as table:
row_key = "phone#4c410523#20190501"
col_filter = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.row_filters.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.row_filters.ColumnQualifierRegexFilter.html(b"os_build")
row = await table.read_row(row_key, row_filter=col_filter)
print(row)
### Python
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
def read_row_partial(project_id, instance_id, table_id):
from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest
from google.cloud.bigtable import row_filters
client = https://docs.cloud.google.com/python/docs/reference/bigtable/latest.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html(project=project_id, admin=True)
instance = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html#google_cloud_bigtable_client_Client_instance(instance_id)
table = instance.table(table_id)
row_key = "phone#4c410523#20190501"
col_filter = row_filters.ColumnQualifierRegexFilter(b"os_build")
row = table.read_row(row_key, filter_=col_filter)
print_row(row)
### C#
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
///
/// /// Reads part of one row from an existing table.
///
/// Your Google Cloud Project ID.
/// Your Google Cloud Bigtable Instance ID.
/// Your Google Cloud Bigtable table ID.
public string ReadRowPartial(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
BigtableClient bigtableClient = BigtableClient.Create();
TableName tableName = new TableName(projectId, instanceId, tableId);
string rowkey = "phone#4c410523#20190501";
RowFilter filter = RowFilters.ColumnQualifierExact("os_build");
Row row = bigtableClient.ReadRow(tableName, rowkey, filter);
return PrintRow(row);
}
### C++
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](google::cloud::bigtable::Table table, std::string const& row_key) {
StatusOr> tuple = table.ReadRow(
row_key, cbt::Filter::ColumnName("stats_summary", "os_build"));
if (!tuple) throw std::move(tuple).status();
if (!tuple->first) {
std::cout << "Row " << row_key << " not found\n";
return;
}
PrintRow(tuple->second);
}
### Node.js
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
const COLUMN_FAMILY = 'stats_summary';
const COLUMN_QUALIFIER = 'os_build';
const rowkey = 'phone#4c410523#20190501';
const [row] = await table
.row(rowkey)
.get([`${COLUMN_FAMILY}:${COLUMN_QUALIFIER}`]);
printRow(rowkey, row);
### PHP
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
use Google\Cloud\Bigtable\BigtableClient;
use Google\Cloud\Bigtable\Filter;
/**
* Read partial row data
*
* @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 read_row_partial(
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);
$rowkey = 'phone#4c410523#20190501';
$rowFilter = Filter::qualifier()->regex('os_build');
$row = $table->readRow($rowkey, ['filter' => $rowFilter]);
print_row($rowkey, $row);
}
### Ruby
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html
table = bigtable.table instance_id, table_id
filter = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-RowFilter.html.qualifier "os_build"
row = table.read_row "phone#4c410523#20190501", filter: filter
print_row row
end
## Read multiple rows
The following code samples show how to get **multiple rows** of data using a set
of row keys.
### Go
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
func readRows(w io.Writer, projectID, instanceID string, tableName string) error {
// projectID := "my-project-id"
// instanceID := "my-instance-id"
// tableName := "mobile-time-series"
ctx := context.Background()
client, err := bigtable.NewClient(ctx, projectID, instanceID)
if err != nil {
return fmt.Errorf("bigtable.NewClient: %w", err)
}
defer client.Close()
tbl := client.Open(tableName)
err = tbl.ReadRows(ctx, bigtable.RowList{"phone#4c410523#20190501", "phone#4c410523#20190502"},
func(row bigtable.Row) bool {
printRow(w, row)
return true
},
)
if err != nil {
return fmt.Errorf("tbl.ReadRows: %w", err)
}
return nil
}
### HBase
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
/**
* Example of reading multiple row keys.
*/
public static void readRows() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRows(projectId, instanceId, tableId);
}
public static void readRows(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
Table table = connection.getTable(TableName.valueOf(tableId));
List queryRowList = new ArrayList();
queryRowList.add(new Get(Bytes.toBytes("phone#4c410523#20190501")));
queryRowList.add(new Get(Bytes.toBytes("phone#4c410523#20190502")));
Result[] rows = table.get(queryRowList);
for (Result row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Java
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
public static void readRows() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRows(projectId, instanceId, tableId);
}
public static void readRows(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
Query query =
Query.create(TableId.of(tableId))
.rowKey("phone#4c410523#20190501")
.rowKey("phone#4c410523#20190502");
ServerStream rows = dataClient.readRows(query);
for (Row row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Python asyncio
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.read_rows_query.ReadRowsQuery.html
async def read_rows(project_id, instance_id, table_id):
async with BigtableDataClientAsync(project=project_id) as client:
async with client.get_table(instance_id, table_id) as table:
query = ReadRowsQuery(
row_keys=[b"phone#4c410523#20190501", b"phone#4c410523#20190502"]
)
async for row in await table.read_rows_stream(query):
print(row)
### Python
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
def read_rows(project_id, instance_id, table_id):
from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest
from google.cloud.bigtable.row_set import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html
client = https://docs.cloud.google.com/python/docs/reference/bigtable/latest.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html(project=project_id, admin=True)
instance = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html#google_cloud_bigtable_client_Client_instance(instance_id)
table = instance.table(table_id)
row_set = RowSet()
https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html#google_cloud_bigtable_row_set_RowSet_add_row_key(b"phone#4c410523#20190501")
https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html#google_cloud_bigtable_row_set_RowSet_add_row_key(b"phone#4c410523#20190502")
rows = table.read_rows(row_set=row_set)
for row in rows:
print_row(row)
### C#
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
///
/// /// Reads multiple rows from an existing table.
///
/// Your Google Cloud Project ID.
/// Your Google Cloud Bigtable Instance ID.
/// Your Google Cloud Bigtable table ID.
public async Task ReadRows(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
BigtableClient bigtableClient = BigtableClient.Create();
TableName tableName = new TableName(projectId, instanceId, tableId);
RowSet rowSet = RowSet.FromRowKeys("phone#4c410523#20190501", "phone#4c410523#20190502");
ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, rowSet);
string result = "";
await foreach(var row in readRowsStream)
{
result += PrintRow(row);
}
return result;
}
### C++
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr& row : table.ReadRows(
cbt::RowSet("phone#4c410523#20190501", "phone#4c410523#20190502"),
cbt::Filter::PassAllFilter())) {
if (!row) throw std::move(row).status();
PrintRow(*row);
}
}
### Node.js
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
const rowKeys = ['phone#4c410523#20190501', 'phone#4c410523#20190502'];
const [rows] = await table.getRows({keys: rowKeys});
rows.forEach(row => printRow(row.id, row.data));
### PHP
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
use Google\Cloud\Bigtable\BigtableClient;
/**
* Read rows using an array of keys
*
* @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 read_rows(
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);
$rows = $table->readRows(
['rowKeys' => ['phone#4c410523#20190501', 'phone#4c410523#20190502']]
);
foreach ($rows as $key => $row) {
print_row($key, $row);
}
}
### Ruby
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html
table = bigtable.table instance_id, table_id
table.read_rows(keys: ["phone#4c410523#20190501", "phone#4c410523#20190502"]).https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ColumnFamilyMap.html do |row|
print_row row
end
## Read a range of rows
The following code samples show how to get **multiple rows** of data using a
**start key and an end key**.
### Go
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
func readRowRange(w io.Writer, projectID, instanceID string, tableName string) error {
// projectID := "my-project-id"
// instanceID := "my-instance-id"
// tableName := "mobile-time-series"
ctx := context.Background()
client, err := bigtable.NewClient(ctx, projectID, instanceID)
if err != nil {
return fmt.Errorf("bigtable.NewClient: %w", err)
}
defer client.Close()
tbl := client.Open(tableName)
err = tbl.ReadRows(ctx, bigtable.NewRange("phone#4c410523#20190501", "phone#4c410523#201906201"),
func(row bigtable.Row) bool {
printRow(w, row)
return true
},
)
if err != nil {
return fmt.Errorf("tbl.ReadRows: %w", err)
}
return nil
}
### HBase
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
/**
* Example of reading a range of rows using a key range.
*/
public static void readRowRange() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRowRange(projectId, instanceId, tableId);
}
public static void readRowRange(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
Table table = connection.getTable(TableName.valueOf(tableId));
Scan rangeQuery =
new Scan()
.withStartRow(Bytes.toBytes("phone#4c410523#20190501"))
.withStopRow(Bytes.toBytes("phone#4c410523#201906201"));
ResultScanner rows = table.getScanner(rangeQuery);
for (Result row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Java
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
public static void readRowRange() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRowRange(projectId, instanceId, tableId);
}
public static void readRowRange(String projectId, String instanceId, String tableId) {
String start = "phone#4c410523#20190501";
String end = "phone#4c410523#201906201";
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
Query query = Query.create(TableId.of(tableId)).range(start, end);
ServerStream rows = dataClient.readRows(query);
for (Row row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Python asyncio
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.read_rows_query.ReadRowsQuery.html
from google.cloud.bigtable.data import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.read_rows_query.RowRange.html
async def read_row_range(project_id, instance_id, table_id):
async with BigtableDataClientAsync(project=project_id) as client:
async with client.get_table(instance_id, table_id) as table:
row_range = RowRange(
start_key=b"phone#4c410523#20190501",
end_key=b"phone#4c410523#201906201",
)
query = ReadRowsQuery(row_ranges=[row_range])
async for row in await table.read_rows_stream(query):
print(row)
### Python
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
def read_row_range(project_id, instance_id, table_id):
from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest
from google.cloud.bigtable.row_set import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html
client = https://docs.cloud.google.com/python/docs/reference/bigtable/latest.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html(project=project_id, admin=True)
instance = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html#google_cloud_bigtable_client_Client_instance(instance_id)
table = instance.table(table_id)
row_set = RowSet()
https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html#google_cloud_bigtable_row_set_RowSet_add_row_range_from_keys(
start_key=b"phone#4c410523#20190501", end_key=b"phone#4c410523#201906201"
)
rows = table.read_rows(row_set=row_set)
for row in rows:
print_row(row)
### C#
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
///
/// /// Reads a range of rows from an existing table.
///
/// Your Google Cloud Project ID.
/// Your Google Cloud Bigtable Instance ID.
/// Your Google Cloud Bigtable table ID.
public async Task ReadRowRange(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
string start = "phone#4c410523#20190501";
string end = "phone#4c410523#201906201";
BigtableClient bigtableClient = BigtableClient.Create();
TableName tableName = new TableName(projectId, instanceId, tableId);
RowSet rowSet = RowSet.FromRowRanges(RowRange.ClosedOpen(start, end));
ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, rowSet);
string result = "";
await foreach (var row in readRowsStream)
{
result += PrintRow(row);
}
return result;
}
### C++
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr& row :
table.ReadRows(cbt::RowRange::Range("phone#4c410523#20190501",
"phone#4c410523#201906201"),
cbt::Filter::PassAllFilter())) {
if (!row) throw std::move(row).status();
PrintRow(*row);
}
}
### Node.js
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
const start = 'phone#4c410523#20190501';
const end = 'phone#4c410523#201906201';
await table
.createReadStream({
start,
end,
})
.on('error', err => {
// Handle the error.
console.log(err);
})
.on('data', row => printRow(row.id, row.data))
.on('end', () => {
// All rows retrieved.
});
### PHP
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
use Google\Cloud\Bigtable\BigtableClient;
/**
* Read using a range for row keys
*
* @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 read_row_range(
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);
$rows = $table->readRows([
'rowRanges' => [
[
'startKeyClosed' => 'phone#4c410523#20190501',
'endKeyOpen' => 'phone#4c410523#201906201'
]
]
]);
foreach ($rows as $key => $row) {
print_row($key, $row);
}
}
### Ruby
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html
table = bigtable.table instance_id, table_id
range = table.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ReadOperations.html.between "phone#4c410523#20190501", "phone#4c410523#201906201"
table.read_rows(ranges: range).https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ColumnFamilyMap.html do |row|
print_row row
end
## Read multiple ranges of rows
The following code samples show how to get **multiple rows** of data using
**multiple start key and end keys** . Be aware that requesting a large number of
row ranges in a single request can have an impact on [read performance](https://docs.cloud.google.com/bigtable/docs/reads#many-row-ranges).
### Go
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
func readRowRanges(w io.Writer, projectID, instanceID string, tableName string) error {
// projectID := "my-project-id"
// instanceID := "my-instance-id"
// tableName := "mobile-time-series"
ctx := context.Background()
client, err := bigtable.NewClient(ctx, projectID, instanceID)
if err != nil {
return fmt.Errorf("bigtable.NewClient: %w", err)
}
defer client.Close()
tbl := client.Open(tableName)
err = tbl.ReadRows(ctx, bigtable.RowRangeList{
bigtable.NewRange("phone#4c410523#20190501", "phone#4c410523#201906201"),
bigtable.NewRange("phone#5c10102#20190501", "phone#5c10102#201906201"),
},
func(row bigtable.Row) bool {
printRow(w, row)
return true
},
)
if err != nil {
return fmt.Errorf("tbl.ReadRows: %w", err)
}
return nil
}
### HBase
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
/**
* Example of reading multiple disjoint row ranges.
*/
public static void readRowRanges() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRowRanges(projectId, instanceId, tableId);
}
public static void readRowRanges(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
Table table = connection.getTable(TableName.valueOf(tableId));
List ranges = new ArrayList<>();
ranges.add(
new RowRange(
Bytes.toBytes("phone#4c410523#20190501"),
true,
Bytes.toBytes("phone#4c410523#20190601"),
false));
ranges.add(
new RowRange(
Bytes.toBytes("phone#5c10102#20190501"),
true,
Bytes.toBytes("phone#5c10102#20190601"),
false));
Filter filter = new MultiRowRangeFilter(ranges);
Scan scan = new Scan().setFilter(filter);
ResultScanner rows = table.getScanner(scan);
for (Result row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Java
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
public static void readRowRanges() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRowRanges(projectId, instanceId, tableId);
}
public static void readRowRanges(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
Query query =
Query.create(TableId.of(tableId))
.range("phone#4c410523#20190501", "phone#4c410523#20190601")
.range("phone#5c10102#20190501", "phone#5c10102#20190601");
ServerStream rows = dataClient.readRows(query);
for (Row row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Python
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
def read_row_ranges(project_id, instance_id, table_id):
from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest
from google.cloud.bigtable.row_set import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html
client = https://docs.cloud.google.com/python/docs/reference/bigtable/latest.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html(project=project_id, admin=True)
instance = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html#google_cloud_bigtable_client_Client_instance(instance_id)
table = instance.table(table_id)
row_set = RowSet()
https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html#google_cloud_bigtable_row_set_RowSet_add_row_range_from_keys(
start_key=b"phone#4c410523#20190501", end_key=b"phone#4c410523#201906201"
)
https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html#google_cloud_bigtable_row_set_RowSet_add_row_range_from_keys(
start_key=b"phone#5c10102#20190501", end_key=b"phone#5c10102#201906201"
)
rows = table.read_rows(row_set=row_set)
for row in rows:
print_row(row)
### C#
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
///
/// /// Reads multiple ranges of rows from an existing table.
///
/// Your Google Cloud Project ID.
/// Your Google Cloud Bigtable Instance ID.
/// Your Google Cloud Bigtable table ID.
public async Task ReadRowRanges(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
BigtableClient bigtableClient = BigtableClient.Create();
TableName tableName = new TableName(projectId, instanceId, tableId);
RowSet rowSet = RowSet.FromRowRanges(RowRange.ClosedOpen("phone#4c410523#20190501", "phone#4c410523#20190601"),
RowRange.ClosedOpen("phone#5c10102#20190501", "phone#5c10102#20190601"));
ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, rowSet);
string result = "";
await foreach (var row in readRowsStream)
{
result += PrintRow(row);
}
return result;
}
### C++
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr& row : table.ReadRows(
cbt::RowSet({cbt::RowRange::Range("phone#4c410523#20190501",
"phone#4c410523#20190601"),
cbt::RowRange::Range("phone#5c10102#20190501",
"phone#5c10102#20190601")}),
cbt::Filter::PassAllFilter())) {
if (!row) throw std::move(row).status();
PrintRow(*row);
}
}
### Node.js
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
await table
.createReadStream({
ranges: [
{
start: 'phone#4c410523#20190501',
end: 'phone#4c410523#20190601',
},
{
start: 'phone#5c10102#20190501',
end: 'phone#5c10102#20190601',
},
],
})
.on('error', err => {
// Handle the error.
console.log(err);
})
.on('data', row => printRow(row.id, row.data))
.on('end', () => {
// All rows retrieved.
});
### PHP
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
use Google\Cloud\Bigtable\BigtableClient;
/**
* Read using multiple ranges for row keys
*
* @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 read_row_ranges(
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);
$rows = $table->readRows([
'rowRanges' => [
[
'startKeyClosed' => 'phone#4c410523#20190501',
'endKeyOpen' => 'phone#4c410523#201906201'
],
[
'startKeyClosed' => 'phone#5c10102#20190501',
'endKeyOpen' => 'phone#5c10102#201906201'
]
]
]);
foreach ($rows as $key => $row) {
print_row($key, $row);
}
}
### Ruby
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html
table = bigtable.table instance_id, table_id
ranges = []
ranges <<
table.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ReadOperations.html.between("phone#4c410523#20190501", "phone#4c410523#201906201") <<
table.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ReadOperations.html.between("phone#5c10102#20190501", "phone#5c10102#201906201")
table.read_rows(ranges: ranges).https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ColumnFamilyMap.html do |row|
print_row row
end
## Read multiple rows using a row key prefix
The following code samples show how to get **multiple rows** of data using a
**row key prefix**.
### Go
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
func readPrefix(w io.Writer, projectID, instanceID string, tableName string) error {
// projectID := "my-project-id"
// instanceID := "my-instance-id"
// tableName := "mobile-time-series"
ctx := context.Background()
client, err := bigtable.NewClient(ctx, projectID, instanceID)
if err != nil {
return fmt.Errorf("bigtable.NewClient: %w", err)
}
defer client.Close()
tbl := client.Open(tableName)
err = tbl.ReadRows(ctx, bigtable.PrefixRange("phone#"),
func(row bigtable.Row) bool {
printRow(w, row)
return true
},
)
if err != nil {
return fmt.Errorf("tbl.ReadRows: %w", err)
}
return nil
}
### HBase
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
/**
* Example of reading a range of rows using a row prefix.
*/
public static void readPrefix() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readPrefix(projectId, instanceId, tableId);
}
public static void readPrefix(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
Table table = connection.getTable(TableName.valueOf(tableId));
Scan prefixScan = new Scan().setRowPrefixFilter(Bytes.toBytes("phone"));
ResultScanner rows = table.getScanner(prefixScan);
for (Result row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Java
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
public static void readPrefix() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readPrefix(projectId, instanceId, tableId);
}
public static void readPrefix(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
Query query = Query.create(TableId.of(tableId)).prefix("phone");
ServerStream rows = dataClient.readRows(query);
for (Row row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Python asyncio
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.read_rows_query.ReadRowsQuery.html
from google.cloud.bigtable.data import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.read_rows_query.RowRange.html
async def read_prefix(project_id, instance_id, table_id):
async with BigtableDataClientAsync(project=project_id) as client:
async with client.get_table(instance_id, table_id) as table:
prefix = "phone#"
end_key = prefix[:-1] + chr(ord(prefix[-1]) + 1)
prefix_range = RowRange(start_key=prefix, end_key=end_key)
query = ReadRowsQuery(row_ranges=[prefix_range])
async for row in await table.read_rows_stream(query):
print(row)
### Python
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
def read_prefix(project_id, instance_id, table_id):
from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest
from google.cloud.bigtable.row_set import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html
client = https://docs.cloud.google.com/python/docs/reference/bigtable/latest.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html(project=project_id, admin=True)
instance = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html#google_cloud_bigtable_client_Client_instance(instance_id)
table = instance.table(table_id)
prefix = "phone#"
end_key = prefix[:-1] + chr(ord(prefix[-1]) + 1)
row_set = RowSet()
https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.row_set.RowSet.html#google_cloud_bigtable_row_set_RowSet_add_row_range_from_keys(prefix.encode("utf-8"), https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.read_rows_query.RowRange.html#google_cloud_bigtable_data_read_rows_query_RowRange_end_key.encode("utf-8"))
rows = table.read_rows(row_set=row_set)
for row in rows:
print_row(row)
### C#
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
///
/// /// Reads rows starting with a prefix from an existing table.
///
/// Your Google Cloud Project ID.
/// Your Google Cloud Bigtable Instance ID.
/// Your Google Cloud Bigtable table ID.
public async Task ReadPrefix(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
BigtableClient bigtableClient = BigtableClient.Create();
TableName tableName = new TableName(projectId, instanceId, tableId);
string prefix = "phone";
char prefixEndChar = prefix[prefix.Length - 1];
prefixEndChar++;
string end = prefix.Substring(0, prefix.Length - 1) + prefixEndChar;
RowSet rowSet = RowSet.FromRowRanges(RowRange.Closed(prefix, end));
ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, rowSet);
string result = "";
await foreach (var row in readRowsStream)
{
result += PrintRow(row);
}
return result;
}
### C++
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr& row : table.ReadRows(
cbt::RowRange::Prefix("phone"), cbt::Filter::PassAllFilter())) {
if (!row) throw std::move(row).status();
PrintRow(*row);
}
}
### Node.js
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
const prefix = 'phone#';
await table
.createReadStream({
prefix,
})
.on('error', err => {
// Handle the error.
console.log(err);
})
.on('data', row => printRow(row.id, row.data))
.on('end', () => {
// All rows retrieved.
});
### PHP
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
use Google\Cloud\Bigtable\BigtableClient;
/**
* Read using a row key prefix
*
* @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 read_prefix(
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);
$prefix = 'phone#';
$end = $prefix;
// Increment the last character of the prefix so the filter matches everything in between
$end[-1] = chr(
ord($end[-1]) + 1
);
$rows = $table->readRows([
'rowRanges' => [
[
'startKeyClosed' => $prefix,
'endKeyClosed' => $end,
]
]
]);
foreach ($rows as $key => $row) {
print_row($key, $row);
}
}
### Ruby
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html
table = bigtable.table instance_id, table_id
prefix = "phone#"
end_key = prefix[0...-1] + prefix[-1].next
range = table.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ReadOperations.html.between prefix, end_key
table.read_rows(ranges: range).https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ColumnFamilyMap.html do |row|
print_row row
end
## Scan in reverse
The following code samples show how to scan in reverse. See the details at
[Reverse scans](https://docs.cloud.google.com/bigtable/docs/reads#reverse-scans). To avoid inefficiency,
limit a reverse scan to about 50 rows.
### Go
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
func readRowsReversed(w io.Writer, projectID, instanceID string, tableName string) error {
// projectID := "my-project-id"
// instanceID := "my-instance-id"
// tableName := "mobile-time-series"
ctx := context.Background()
client, err := bigtable.NewClient(ctx, projectID, instanceID)
if err != nil {
return fmt.Errorf("bigtable.NewClient: %w", err)
}
defer client.Close()
tbl := client.Open(tableName)
err = tbl.ReadRows(ctx, bigtable.NewRange("phone#5c10102", "phone#5c10103"),
func(row bigtable.Row) bool {
printRow(w, row)
return true
},
bigtable.ReverseScan())
if err != nil {
return fmt.Errorf("tbl.ReadRows: %w", err)
}
return nil
}
### HBase
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
/**
* Example of reading a range of rows in reverse order.
*/
public static void readRowsReversed() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRowsReversed(projectId, instanceId, tableId);
}
public static void readRowsReversed(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
Table table = connection.getTable(TableName.valueOf(tableId));
Scan revScan =
new Scan()
.setReversed(true)
.setLimit(2)
.withStartRow(Bytes.toBytes("phone#4c410523#20190505"));
ResultScanner rows = table.getScanner(revScan);
for (Result row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Java
Because this example uses a prefix *and* start and end row keys, it returns a
result from the union of those two filters.
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
public static void readRowsReversed() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readRowsReversed(projectId, instanceId, tableId);
}
public static void readRowsReversed(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
Query query =
Query.create(TableId.of(tableId))
.reversed(true)
.limit(3)
.prefix("phone#4c410523")
.range("phone#5c10102", "phone#5c10103");
ServerStream rows = dataClient.readRows(query);
for (Row row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### C++
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::Options;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
auto reader = table.ReadRows(
cbt::RowRange::RightOpen("phone#5c10102", "phone#5c10103"), 3,
cbt::Filter::PassAllFilter(),
Options{}.set(true));
for (StatusOr& row : reader) {
if (!row) throw std::move(row).status();
PrintRow(*row);
}
}
## Read with filters
The following code samples show how to get **multiple rows** of data using a
**row filter** . To learn more about the types of filters that you can use in
read requests, see the [overview of filters](https://docs.cloud.google.com/bigtable/docs/filters). Additional [code samples](https://docs.cloud.google.com/bigtable/docs/using-filters) showing how to implement various types of filters in multiple
languages are also available.
> [!NOTE]
> **Note:** The HBase client for Java uses HBase's filter APIs instead of the Bigtable Data API. To learn about HBase's filter APIs, see the [HBase documentation](https://hbase.apache.org/book.html#client.filter).
### Go
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
func readFilter(w io.Writer, projectID, instanceID string, tableName string) error {
// projectID := "my-project-id"
// instanceID := "my-instance-id"
// tableName := "mobile-time-series"
ctx := context.Background()
client, err := bigtable.NewClient(ctx, projectID, instanceID)
if err != nil {
return fmt.Errorf("bigtable.NewClient: %w", err)
}
defer client.Close()
tbl := client.Open(tableName)
err = tbl.ReadRows(ctx, bigtable.RowRange{},
func(row bigtable.Row) bool {
printRow(w, row)
return true
},
bigtable.RowFilter(bigtable.ValueFilter("PQ2A.*$")),
)
if err != nil {
return fmt.Errorf("tbl.ReadRows: %w", err)
}
return nil
}
### HBase
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
/**
* Example of filtering row contents using filters.
*/
public static void readFilter() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readFilter(projectId, instanceId, tableId);
}
public static void readFilter(String projectId, String instanceId, String tableId) {
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests.
try (Connection connection = BigtableConfiguration.connect(projectId, instanceId)) {
Table table = connection.getTable(TableName.valueOf(tableId));
ValueFilter valueFilter =
new ValueFilter(CompareOp.EQUAL, new RegexStringComparator("PQ2A.*"));
Scan scan = new Scan().setFilter(valueFilter);
ResultScanner rows = table.getScanner(scan);
for (Result row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Java
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
public static void readFilter() {
// TODO(developer): Replace these variables before running the sample.
String projectId = "my-project-id";
String instanceId = "my-instance-id";
String tableId = "mobile-time-series";
readFilter(projectId, instanceId, tableId);
}
public static void readFilter(String projectId, String instanceId, String tableId) {
Filters.Filter filter = FILTERS.value().regex("PQ2A.*");
// Initialize client that will be used to send requests. This client only needs to be created
// once, and can be reused for multiple requests. After completing all of your requests, call
// the "close" method on the client to safely clean up any remaining background resources.
try (BigtableDataClient dataClient = BigtableDataClient.create(projectId, instanceId)) {
Query query = Query.create(TableId.of(tableId)).filter(filter);
ServerStream rows = dataClient.readRows(query);
for (Row row : rows) {
printRow(row);
}
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}
### Python asyncio
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
from google.cloud.bigtable.data import BigtableDataClientAsync
from google.cloud.bigtable.data import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.read_rows_query.ReadRowsQuery.html
from google.cloud.bigtable.data import https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.row_filters.html
async def read_with_filter(project_id, instance_id, table_id):
async with BigtableDataClientAsync(project=project_id) as client:
async with client.get_table(instance_id, table_id) as table:
row_filter = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.row_filters.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.data.row_filters.ValueRegexFilter.html(b"PQ2A.*$")
query = ReadRowsQuery(row_filter=row_filter)
async for row in await table.read_rows_stream(query):
print(row)
### Python
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
def read_filter(project_id, instance_id, table_id):
from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigtable/latest
from google.cloud.bigtable import row_filters
client = https://docs.cloud.google.com/python/docs/reference/bigtable/latest.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html(project=project_id, admin=True)
instance = https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.html.https://docs.cloud.google.com/python/docs/reference/bigtable/latest/google.cloud.bigtable.client.Client.html#google_cloud_bigtable_client_Client_instance(instance_id)
table = instance.table(table_id)
rows = table.read_rows(filter_=row_filters.ValueRegexFilter(b"PQ2A.*$"))
for row in rows:
print_row(row)
### C#
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
///
/// /// Reads using a filter from an existing table.
///
/// Your Google Cloud Project ID.
/// Your Google Cloud Bigtable Instance ID.
/// Your Google Cloud Bigtable table ID.
public async Task ReadFilter(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
BigtableClient bigtableClient = BigtableClient.Create();
TableName tableName = new TableName(projectId, instanceId, tableId);
RowFilter filter = RowFilters.ValueRegex("PQ2A.*");
ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, filter: filter);
string result = "";
await foreach (var row in readRowsStream)
{
result += PrintRow(row);
}
return result;
}
### C++
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr& row :
table.ReadRows(cbt::RowRange::InfiniteRange(),
cbt::Filter::ValueRegex("PQ2A.*"))) {
if (!row) throw std::move(row).status();
PrintRow(*row);
}
}
### Node.js
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
const filter = {
value: /PQ2A.*$/,
};
await table
.createReadStream({
filter,
})
.on('error', err => {
// Handle the error.
console.log(err);
})
.on('data', row => printRow(row.id, row.data))
.on('end', () => {
// All rows retrieved.
});
### PHP
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
use Google\Cloud\Bigtable\BigtableClient;
use Google\Cloud\Bigtable\Filter;
/**
* Read using a filter
*
* @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 read_filter(
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);
$rowFilter = Filter::value()->regex('PQ2A.*$');
$rows = $table->readRows([
'filter' => $rowFilter
]);
foreach ($rows as $key => $row) {
print_row($key, $row);
}
}
### Ruby
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html.https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html
table = bigtable.table instance_id, table_id
filter = Google::Cloud::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable.html::https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-RowFilter.html.value "PQ2A.*$"
table.read_rows(filter: filter).https://docs.cloud.google.com/ruby/docs/reference/google-cloud-bigtable/latest/Google-Cloud-Bigtable-ColumnFamilyMap.html do |row|
print_row row
end
## Read from an authorized view
The following examples show how to send a read request to an authorized view.
The syntax is similar to reading from a table except you must also provide the
authorized view ID.
### Java
This example shows how to read a single row from an authorized view.
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
try {
System.out.println("\nReading a single row by row key from an authorized view");
Row row =
dataClient.readRow(AuthorizedViewId.of(tableId, authorizedViewId), ROW_KEY_PREFIX + 0);
System.out.println("Row: " + row.getKey().toStringUtf8());
for (RowCell cell : row.getCells()) {
System.out.printf(
"Family: %s Qualifier: %s Value: %s%n",
cell.getFamily(), cell.getQualifier().toStringUtf8(), cell.getValue().toStringUtf8());
}
return row;
} catch (NotFoundException e) {
System.err.println("Failed to read from a non-existent authorized view: " + e.getMessage());
return null;
}
This example shows how to read from an authorized view with a filter.
To learn how to install and use the client library for Bigtable, see
[Bigtable client libraries](https://docs.cloud.google.com/bigtable/docs/reference/libraries).
To authenticate to Bigtable, set up Application Default Credentials.
For more information, see
[Set up authentication for client libraries](https://docs.cloud.google.com/bigtable/docs/authentication#client-libs).
try {
// A filter that matches only the most recent cell within each column
Filter filter = FILTERS.limit().cellsPerColumn(1);
System.out.println("\nScanning authorized view with filter");
Query query = Query.create(AuthorizedViewId.of(tableId, authorizedViewId)).filter(filter);
ServerStream rowStream = dataClient.readRows(query);
List authorizedViewRows = new ArrayList<>();
for (Row r : rowStream) {
System.out.println("Row Key: " + r.getKey().toStringUtf8());
authorizedViewRows.add(r);
for (RowCell cell : r.getCells()) {
System.out.printf(
"Family: %s Qualifier: %s Value: %s%n",
cell.getFamily(), cell.getQualifier().toStringUtf8(), cell.getValue().toStringUtf8());
}
}
return authorizedViewRows;
} catch (NotFoundException e) {
System.err.println("Failed to read a non-existent authorized view: " + e.getMessage());
return null;
}
## What's next
- [Learn more about reading data.](https://docs.cloud.google.com/bigtable/docs/reads)
- [Explore the types of filters that you can use.](https://docs.cloud.google.com/bigtable/docs/filters)
- [Review code samples that show how to implement filters.](https://docs.cloud.google.com/bigtable/docs/using-filters)
- [Read about Bigtable writes.](https://docs.cloud.google.com/bigtable/docs/writes)
- [Use the Bigtable emulator.](https://docs.cloud.google.com/bigtable/docs/emulator)