Read examples
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.
Read a single row
The following code samples show how to get a single row of data using the row key.
Go
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
/**
* 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
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, rowkey);
printRow(row);
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}Python
def read_row(project_id, instance_id, table_id):
client = bigtable.Client(project=project_id, admin=True)
instance = client.instance(instance_id)
table = instance.table(table_id)
row_key = "phone#4c410523#20190501"
row = table.read_row(row_key)
print_row(row)
C#
/// <summary>
/// /// Reads one row 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 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++
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](google::cloud::bigtable::Table table, std::string const& row_key) {
StatusOr<std::pair<bool, cbt::Row>> 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
const rowkey = 'phone#4c410523#20190501';
const [row] = await table.row(rowkey).get();
printRow(rowkey, row.data);PHP
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
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::Bigtable.new
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
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
/**
* 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
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, rowkey, filter);
printRow(row);
} catch (IOException e) {
System.out.println(
"Unable to initialize service client, as a network error occurred: \n" + e.toString());
}
}Python
def read_row_partial(project_id, instance_id, table_id):
client = bigtable.Client(project=project_id, admin=True)
instance = 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#
/// <summary>
/// /// Reads part of one row 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 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++
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](google::cloud::bigtable::Table table, std::string const& row_key) {
StatusOr<std::pair<bool, cbt::Row>> 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
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
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
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id
filter = Google::Cloud::Bigtable::RowFilter.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
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
/**
* 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<Get> queryRowList = new ArrayList<Get>();
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
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).rowKey("phone#4c410523#20190501").rowKey("phone#4c410523#20190502");
ServerStream<Row> 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
def read_rows(project_id, instance_id, table_id):
client = bigtable.Client(project=project_id, admin=True)
instance = client.instance(instance_id)
table = instance.table(table_id)
row_set = RowSet()
row_set.add_row_key(b"phone#4c410523#20190501")
row_set.add_row_key(b"phone#4c410523#20190502")
rows = table.read_rows(row_set=row_set)
for row in rows:
print_row(row)
C#
/// <summary>
/// /// Reads multiple rows 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 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 = "";
readRowsStream.ForEach(row => result += printRow(row));
return result;
}C++
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr<cbt::Row>& 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
const rowKeys = ['phone#4c410523#20190501', 'phone#4c410523#20190502'];
const [rows] = await table.getRows({keys: rowKeys});
rows.forEach(row => printRow(row.id, row.data));PHP
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
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id
table.read_rows(keys: ["phone#4c410523#20190501", "phone#4c410523#20190502"]).each do |row|
print_row row
endRead 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
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
/**
* 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
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).range(start, end);
ServerStream<Row> 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
def read_row_range(project_id, instance_id, table_id):
client = bigtable.Client(project=project_id, admin=True)
instance = client.instance(instance_id)
table = instance.table(table_id)
row_set = RowSet()
row_set.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#
/// <summary>
/// /// Reads a range of rows 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 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 = "";
readRowsStream.ForEach(row => result += printRow(row));
return result;
}C++
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr<cbt::Row>& 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
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
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
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id
range = table.new_row_range.between "phone#4c410523#20190501", "phone#4c410523#201906201"
table.read_rows(ranges: range).each do |row|
print_row row
endRead 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.
Go
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
/**
* 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<RowRange> 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
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)
.range("phone#4c410523#20190501", "phone#4c410523#20190601")
.range("phone#5c10102#20190501", "phone#5c10102#20190601");
ServerStream<Row> 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
def read_row_ranges(project_id, instance_id, table_id):
client = bigtable.Client(project=project_id, admin=True)
instance = client.instance(instance_id)
table = instance.table(table_id)
row_set = RowSet()
row_set.add_row_range_from_keys(
start_key=b"phone#4c410523#20190501", end_key=b"phone#4c410523#201906201"
)
row_set.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#
/// <summary>
/// /// Reads multiple ranges of rows 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 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 = "";
readRowsStream.ForEach(row => result += printRow(row));
return result;
}C++
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr<cbt::Row>& 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
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
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
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id
ranges = []
ranges <<
table.new_row_range.between("phone#4c410523#20190501", "phone#4c410523#201906201") <<
table.new_row_range.between("phone#5c10102#20190501", "phone#5c10102#201906201")
table.read_rows(ranges: ranges).each do |row|
print_row row
endRead 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
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
/**
* 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
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).prefix("phone");
ServerStream<Row> 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
def read_prefix(project_id, instance_id, table_id):
client = bigtable.Client(project=project_id, admin=True)
instance = client.instance(instance_id)
table = instance.table(table_id)
prefix = "phone#"
end_key = prefix[:-1] + chr(ord(prefix[-1]) + 1)
row_set = RowSet()
row_set.add_row_range_from_keys(prefix.encode("utf-8"), end_key.encode("utf-8"))
rows = table.read_rows(row_set=row_set)
for row in rows:
print_row(row)
C#
/// <summary>
/// /// Reads rows starting with a prefix 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 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 = "";
readRowsStream.ForEach(row => result += printRow(row));
return result;
}C++
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr<cbt::Row>& row : table.ReadRows(
cbt::RowRange::Prefix("phone"), cbt::Filter::PassAllFilter())) {
if (!row) throw std::move(row).status();
PrintRow(*row);
}
}Node.js
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
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
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id
prefix = "phone#"
end_key = prefix[0...-1] + prefix[-1].next
range = table.new_row_range.between prefix, end_key
table.read_rows(ranges: range).each do |row|
print_row row
endScan in reverse
The following code samples show how to scan in reverse. See the details at Reverse scans. To avoid inefficiency, limit a reverse scan to about 50 rows.HBase
/**
* 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.
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)
.reversed(true)
.limit(3)
.prefix("phone#4c410523")
.range("phone#5c10102", "phone#5c10103");
ServerStream<Row> 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++
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<cbt::ReverseScanOption>(true));
for (StatusOr<cbt::Row>& 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. Additional code samples showing how to implement various types of filters in multiple languages are also available.
Go
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
/**
* 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
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).filter(filter);
ServerStream<Row> 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
def read_filter(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.ValueRegexFilter(b"PQ2A.*$"))
for row in rows:
print_row(row)
C#
/// <summary>
/// /// Reads using a filter from an existing table.
///</summary>
/// <param name="projectId">Your Google Cloud Project ID.</param>
/// <param name="instanceId">Your Google Cloud Bigtable Instance ID.</param>
/// <param name="tableId">Your Google Cloud Bigtable table ID.</param>
public string readFilter(string projectId = "YOUR-PROJECT-ID", string instanceId = "YOUR-INSTANCE-ID", string tableId = "YOUR-TABLE-ID")
{
BigtableClient bigtableClient = BigtableClient.Create();
TableName tableName = new TableName(projectId, instanceId, tableId);
RowFilter filter = RowFilters.ValueRegex("PQ2A.*");
ReadRowsStream readRowsStream = bigtableClient.ReadRows(tableName, filter: filter);
string result = "";
readRowsStream.ForEach(row => result += printRow(row));
return result;
}C++
namespace cbt = ::google::cloud::bigtable;
using ::google::cloud::StatusOr;
[](cbt::Table table) {
// Read and print the rows.
for (StatusOr<cbt::Row>& row :
table.ReadRows(cbt::RowRange::InfiniteRange(),
cbt::Filter::ValueRegex("PQ2A.*"))) {
if (!row) throw std::move(row).status();
PrintRow(*row);
}
}Node.js
const filter = {
value: /PQ2A.*$/,
};
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
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, $row);
}
}Ruby
# instance_id = "my-instance"
# table_id = "my-table"
bigtable = Google::Cloud::Bigtable.new
table = bigtable.table instance_id, table_id
filter = Google::Cloud::Bigtable::RowFilter.value "PQ2A.*$"
table.read_rows(filter: filter).each do |row|
print_row row
endWhat's next
- Learn more about reading data.
- Explore the types of filters that you can use.
- Review code samples that show how to implement filters.
- Read about Bigtable writes.
- Use the Bigtable emulator.