Halaman ini menjelaskan cara menyisipkan, memperbarui, dan menghapus data Spanner menggunakan
pernyataan Bahasa Manipulasi Data (DML). Anda dapat menjalankan pernyataan DML menggunakan library klien, Google Cloud Console, dan alat command line gcloud. Anda dapat menjalankan pernyataan DML Terpartisi
menggunakan library klien dan alat command line
gcloud.
Untuk referensi sintaksis DML lengkap, lihat sintaksis Bahasa Manipulasi Data untuk database dialek GoogleSQL atau Bahasa manipulasi data PostgreSQL untuk database dialek PostgreSQL
Menggunakan DML
DML mendukung pernyataan INSERT, UPDATE, dan DELETE di konsol Google Cloud, Google Cloud CLI, dan library klien.
Mengunci
Anda mengeksekusi pernyataan DML di dalam transaksi baca-tulis. Saat membaca data, Spanner
memperoleh kunci baca bersama di bagian terbatas dari rentang baris yang Anda baca. Secara khusus, parser memperoleh kunci ini hanya pada kolom yang Anda akses. Kunci dapat menyertakan data yang tidak memenuhi kondisi filter klausa WHERE.
Saat memodifikasi data menggunakan pernyataan DML, Spanner akan memperoleh kunci eksklusif pada data tertentu yang Anda ubah. Selain itu, mode ini memperoleh kunci bersama dengan cara yang sama seperti saat Anda membaca data. Jika permintaan Anda mencakup rentang baris yang besar, atau keseluruhan tabel, kunci bersama dapat mencegah transaksi lain diproses secara paralel.
Untuk mengubah data seefisien mungkin, gunakan klausa WHERE yang memungkinkan Spanner hanya membaca baris yang diperlukan. Anda dapat mencapai sasaran ini dengan filter pada kunci utama, atau pada kunci dari indeks sekunder. Klausa WHERE membatasi cakupan kunci bersama dan memungkinkan Spanner memproses update dengan lebih efisien.
Misalnya, anggaplah salah satu musisi dalam tabel Singers mengubah nama depannya, dan Anda perlu memperbarui nama tersebut di database. Anda dapat mengeksekusi pernyataan DML berikut, tetapi pernyataan ini memaksa Spanner untuk memindai seluruh tabel dan memperoleh kunci bersama yang menutupi seluruh tabel. Akibatnya, Spanner harus membaca data lebih dari yang diperlukan, dan transaksi serentak tidak dapat mengubah data secara paralel:
-- ANTI-PATTERN: SENDING AN UPDATE WITHOUT THE PRIMARY KEY COLUMN
-- IN THE WHERE CLAUSE
UPDATE Singers SET FirstName = "Marcel"
WHERE FirstName = "Marc" AND LastName = "Richards";
Untuk membuat pembaruan lebih efisien, sertakan kolom SingerId dalam klausa WHERE. Kolom SingerId adalah satu-satunya kolom kunci utama untuk
tabel Singers:
-- ANTI-PATTERN: SENDING AN UPDATE THAT MUST SCAN THE ENTIRE TABLE
UPDATE Singers SET FirstName = "Marcel"
WHERE FirstName = "Marc" AND LastName = "Richards"
Jika tidak ada indeks pada FirstName atau LastName, Anda harus
memindai seluruh tabel untuk menemukan penyanyi target. Jika Anda tidak ingin menambahkan indeks sekunder
untuk membuat update lebih efisien, sertakan kolom SingerId
dalam klausa WHERE.
Kolom SingerId adalah satu-satunya kolom kunci utama untuk
tabel Singers. Untuk menemukannya, jalankan SELECT dalam transaksi
hanya baca yang terpisah sebelum transaksi pembaruan:
SELECT SingerId
FROM Singers
WHERE FirstName = "Marc" AND LastName = "Richards"
-- Recommended: Including a seekable filter in the where clause
UPDATE Singers SET FirstName = "Marcel"
WHERE SingerId = 1;
Serentak
Spanner secara berurutan menjalankan semua pernyataan SQL (SELECT,
INSERT, UPDATE, dan DELETE) dalam transaksi. Keduanya tidak dijalankan
secara bersamaan. Satu-satunya pengecualian adalah Spanner mungkin dapat mengeksekusi beberapa
pernyataan SELECT secara serentak, karena merupakan operasi hanya baca.
Batas transaksi
Transaksi yang menyertakan pernyataan DML memiliki batas yang sama dengan transaksi lainnya. Jika Anda memiliki perubahan berskala besar, pertimbangkan untuk menggunakan DML Berpartisi.
Jika pernyataan DML dalam transaksi menghasilkan lebih dari 80.000 mutasi, pernyataan DML yang mendorong transaksi melebihi batas akan menampilkan error
BadUsagedengan pesan tentang terlalu banyak mutasi.Jika pernyataan DML dalam transaksi menghasilkan transaksi yang lebih besar dari 100 MB, pernyataan DML yang mendorong transaksi melebihi batas akan menampilkan error
BadUsagedengan pesan tentang transaksi yang melebihi batas ukuran.
Mutasi yang dilakukan menggunakan DML tidak dikembalikan ke klien. Class tersebut akan digabungkan ke dalam permintaan commit saat di-commit dan diperhitungkan dalam batas ukuran maksimum. Meskipun ukuran permintaan commit yang Anda kirim kecil, transaksi mungkin masih melebihi batas ukuran yang diizinkan.
Menjalankan pernyataan di konsol Google Cloud
Gunakan langkah-langkah berikut untuk menjalankan pernyataan DML di konsol Google Cloud.
Buka halaman Instance Spanner.
Pilih project Anda dari menu drop-down di toolbar.
Klik nama instance yang berisi database Anda untuk membuka halaman Instance details.
Di tab Ringkasan, klik nama database Anda. Halaman Database details akan muncul.
Klik Spanner Studio.
Masukkan pernyataan DML. Misalnya, pernyataan berikut menambahkan baris baru ke tabel
Singers.INSERT Singers (SingerId, FirstName, LastName) VALUES (1, 'Marc', 'Richards')Klik Jalankan kueri. Konsol Google Cloud akan menampilkan hasilnya.
Menjalankan pernyataan dengan Google Cloud CLI
Untuk menjalankan pernyataan DML, gunakan perintah
gcloud spanner databases execute-sql. Contoh berikut menambahkan baris baru ke tabel Singers.
gcloud spanner databases execute-sql example-db --instance=test-instance \ --sql="INSERT Singers (SingerId, FirstName, LastName) VALUES (1, 'Marc', 'Richards')"
Mengubah data menggunakan library klien
Untuk menjalankan pernyataan DML menggunakan library klien:
- Buat transaksi baca-tulis.
- Panggil metode library klien untuk eksekusi DML dan teruskan pernyataan DML.
- Menggunakan nilai hasil dari metode eksekusi DML untuk mendapatkan jumlah baris yang disisipkan, diperbarui, atau dihapus.
Contoh kode berikut menyisipkan baris baru ke dalam tabel Singers.
C++
Anda menggunakan fungsi ExecuteDml() untuk mengeksekusi pernyataan DML.
void DmlStandardInsert(google::cloud::spanner::Client client) {
using ::google::cloud::StatusOr;
namespace spanner = ::google::cloud::spanner;
std::int64_t rows_inserted;
auto commit_result = client.Commit(
[&client, &rows_inserted](
spanner::Transaction txn) -> StatusOr<spanner::Mutations> {
auto insert = client.ExecuteDml(
std::move(txn),
spanner::SqlStatement(
"INSERT INTO Singers (SingerId, FirstName, LastName)"
" VALUES (10, 'Virginia', 'Watson')"));
if (!insert) return std::move(insert).status();
rows_inserted = insert->RowsModified();
return spanner::Mutations{};
});
if (!commit_result) throw std::move(commit_result).status();
std::cout << "Rows inserted: " << rows_inserted;
std::cout << "Insert was successful [spanner_dml_standard_insert]\n";
}C#
Anda menggunakan metode ExecuteNonQueryAsync() untuk mengeksekusi pernyataan DML.
using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;
public class InsertUsingDmlCoreAsyncSample
{
public async Task<int> InsertUsingDmlCoreAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
using var cmd = connection.CreateDmlCommand("INSERT Singers (SingerId, FirstName, LastName) VALUES (10, 'Virginia', 'Watson')");
int rowCount = await cmd.ExecuteNonQueryAsync();
Console.WriteLine($"{rowCount} row(s) inserted...");
return rowCount;
}
}Go
Anda menggunakan metode Update() untuk mengeksekusi pernyataan DML.
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
)
func insertUsingDML(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `INSERT Singers (SingerId, FirstName, LastName)
VALUES (10, 'Virginia', 'Watson')`,
}
rowCount, err := txn.Update(ctx, stmt)
if err != nil {
return err
}
fmt.Fprintf(w, "%d record(s) inserted.\n", rowCount)
return nil
})
return err
}
Java
Anda menggunakan metode executeUpdate() untuk mengeksekusi pernyataan DML.
static void insertUsingDml(DatabaseClient dbClient) {
dbClient
.readWriteTransaction()
.run(transaction -> {
String sql =
"INSERT INTO Singers (SingerId, FirstName, LastName) "
+ " VALUES (10, 'Virginia', 'Watson')";
long rowCount = transaction.executeUpdate(Statement.of(sql));
System.out.printf("%d record inserted.\n", rowCount);
return null;
});
}Node.js
Anda menggunakan metode runUpdate() untuk mengeksekusi pernyataan DML.
// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rowCount] = await transaction.runUpdate({
sql: 'INSERT Singers (SingerId, FirstName, LastName) VALUES (10, @firstName, @lastName)',
params: {
firstName: 'Virginia',
lastName: 'Watson',
},
});
console.log(
`Successfully inserted ${rowCount} record into the Singers table.`
);
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});PHP
Anda menggunakan metode executeUpdate() untuk mengeksekusi pernyataan DML.
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Transaction;
/**
* Inserts sample data into the given database with a DML statement.
*
* The database and table must already exist and can be created using
* `create_database`.
* Example:
* ```
* insert_data($instanceId, $databaseId);
* ```
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function insert_data_with_dml(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$database->runTransaction(function (Transaction $t) {
$rowCount = $t->executeUpdate(
'INSERT Singers (SingerId, FirstName, LastName) '
. " VALUES (10, 'Virginia', 'Watson')");
$t->commit();
printf('Inserted %d row(s).' . PHP_EOL, $rowCount);
});
}Python
Anda menggunakan metode execute_update() untuk mengeksekusi pernyataan DML.
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def insert_singers(transaction):
row_ct = transaction.execute_update(
"INSERT INTO Singers (SingerId, FirstName, LastName) "
" VALUES (10, 'Virginia', 'Watson')"
)
print("{} record(s) inserted.".format(row_ct))
database.run_in_transaction(insert_singers)Ruby
Anda menggunakan metode execute_update() untuk mengeksekusi pernyataan DML.
# project_id = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"
require "google/cloud/spanner"
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
row_count = 0
client.transaction do |transaction|
row_count = transaction.execute_update(
"INSERT INTO Singers (SingerId, FirstName, LastName) VALUES (10, 'Virginia', 'Watson')"
)
end
puts "#{row_count} record inserted."Contoh kode berikut memperbarui kolom MarketingBudget dalam tabel Albums
berdasarkan klausa WHERE.
C++
void DmlStandardUpdate(google::cloud::spanner::Client client) {
using ::google::cloud::StatusOr;
namespace spanner = ::google::cloud::spanner;
auto commit_result = client.Commit(
[&client](spanner::Transaction txn) -> StatusOr<spanner::Mutations> {
auto update = client.ExecuteDml(
std::move(txn),
spanner::SqlStatement(
"UPDATE Albums SET MarketingBudget = MarketingBudget * 2"
" WHERE SingerId = 1 AND AlbumId = 1"));
if (!update) return std::move(update).status();
return spanner::Mutations{};
});
if (!commit_result) throw std::move(commit_result).status();
std::cout << "Update was successful [spanner_dml_standard_update]\n";
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;
public class UpdateUsingDmlCoreAsyncSample
{
public async Task<int> UpdateUsingDmlCoreAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
using var cmd = connection.CreateDmlCommand("UPDATE Albums SET MarketingBudget = MarketingBudget * 2 WHERE SingerId = 1 and AlbumId = 1");
int rowCount = await cmd.ExecuteNonQueryAsync();
Console.WriteLine($"{rowCount} row(s) updated...");
return rowCount;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
)
func updateUsingDML(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `UPDATE Albums
SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 1`,
}
rowCount, err := txn.Update(ctx, stmt)
if err != nil {
return err
}
fmt.Fprintf(w, "%d record(s) updated.\n", rowCount)
return nil
})
return err
}
Java
static void updateUsingDml(DatabaseClient dbClient) {
dbClient
.readWriteTransaction()
.run(transaction -> {
String sql =
"UPDATE Albums "
+ "SET MarketingBudget = MarketingBudget * 2 "
+ "WHERE SingerId = 1 and AlbumId = 1";
long rowCount = transaction.executeUpdate(Statement.of(sql));
System.out.printf("%d record updated.\n", rowCount);
return null;
});
}Node.js
// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rowCount] = await transaction.runUpdate({
sql: `UPDATE Albums SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 1`,
});
console.log(`Successfully updated ${rowCount} record.`);
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});PHP
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Transaction;
/**
* Updates sample data in the database with a DML statement.
*
* This requires the `MarketingBudget` column which must be created before
* running this sample. You can add the column by running the `add_column`
* sample or by running this DDL statement against your database:
*
* ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
*
* Example:
* ```
* update_data($instanceId, $databaseId);
* ```
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function update_data_with_dml(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$database->runTransaction(function (Transaction $t) {
$rowCount = $t->executeUpdate(
'UPDATE Albums '
. 'SET MarketingBudget = MarketingBudget * 2 '
. 'WHERE SingerId = 1 and AlbumId = 1');
$t->commit();
printf('Updated %d row(s).' . PHP_EOL, $rowCount);
});
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def update_albums(transaction):
row_ct = transaction.execute_update(
"UPDATE Albums "
"SET MarketingBudget = MarketingBudget * 2 "
"WHERE SingerId = 1 and AlbumId = 1"
)
print("{} record(s) updated.".format(row_ct))
database.run_in_transaction(update_albums)Ruby
# project_id = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"
require "google/cloud/spanner"
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
row_count = 0
client.transaction do |transaction|
row_count = transaction.execute_update(
"UPDATE Albums
SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 1"
)
end
puts "#{row_count} record updated."Contoh kode berikut menghapus semua baris dalam tabel Singers dengan kolom FirstName adalah Alice.
C++
void DmlStandardDelete(google::cloud::spanner::Client client) {
using ::google::cloud::StatusOr;
namespace spanner = ::google::cloud::spanner;
auto commit_result = client.Commit([&client](spanner::Transaction txn)
-> StatusOr<spanner::Mutations> {
auto dele = client.ExecuteDml(
std::move(txn),
spanner::SqlStatement("DELETE FROM Singers WHERE FirstName = 'Alice'"));
if (!dele) return std::move(dele).status();
return spanner::Mutations{};
});
if (!commit_result) throw std::move(commit_result).status();
std::cout << "Delete was successful [spanner_dml_standard_delete]\n";
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;
public class DeleteUsingDmlCoreAsyncSample
{
public async Task<int> DeleteUsingDmlCoreAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
using var cmd = connection.CreateDmlCommand("DELETE FROM Singers WHERE FirstName = 'Alice'");
int rowCount = await cmd.ExecuteNonQueryAsync();
Console.WriteLine($"{rowCount} row(s) deleted...");
return rowCount;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
)
func deleteUsingDML(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{SQL: `DELETE FROM Singers WHERE FirstName = 'Alice'`}
rowCount, err := txn.Update(ctx, stmt)
if err != nil {
return err
}
fmt.Fprintf(w, "%d record(s) deleted.\n", rowCount)
return nil
})
return err
}
Java
static void deleteUsingDml(DatabaseClient dbClient) {
dbClient
.readWriteTransaction()
.run(transaction -> {
String sql = "DELETE FROM Singers WHERE FirstName = 'Alice'";
long rowCount = transaction.executeUpdate(Statement.of(sql));
System.out.printf("%d record deleted.\n", rowCount);
return null;
});
}Node.js
// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rowCount] = await transaction.runUpdate({
sql: "DELETE FROM Singers WHERE FirstName = 'Alice'",
});
console.log(`Successfully deleted ${rowCount} record.`);
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});PHP
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Transaction;
/**
* Deletes sample data in the database with a DML statement.
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function delete_data_with_dml(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$database->runTransaction(function (Transaction $t) {
$rowCount = $t->executeUpdate(
"DELETE FROM Singers WHERE FirstName = 'Alice'");
$t->commit();
printf('Deleted %d row(s).' . PHP_EOL, $rowCount);
});
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def delete_singers(transaction):
row_ct = transaction.execute_update(
"DELETE FROM Singers WHERE FirstName = 'Alice'"
)
print("{} record(s) deleted.".format(row_ct))
database.run_in_transaction(delete_singers)Ruby
# project_id = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"
require "google/cloud/spanner"
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
row_count = 0
client.transaction do |transaction|
row_count = transaction.execute_update(
"DELETE FROM Singers WHERE FirstName = 'Alice'"
)
end
puts "#{row_count} record deleted."Contoh berikut, khusus untuk database dialek GoogleSQL, menggunakan
STRUCT dengan parameter terikat
untuk mengupdate LastName di baris yang difilter oleh FirstName dan LastName.
GoogleSQL
C++
void DmlStructs(google::cloud::spanner::Client client) {
namespace spanner = ::google::cloud::spanner;
std::int64_t rows_modified = 0;
auto commit_result =
client.Commit([&client, &rows_modified](spanner::Transaction const& txn)
-> google::cloud::StatusOr<spanner::Mutations> {
auto singer_info = std::make_tuple("Marc", "Richards");
auto sql = spanner::SqlStatement(
"UPDATE Singers SET FirstName = 'Keith' WHERE "
"STRUCT<FirstName String, LastName String>(FirstName, LastName) "
"= @name",
{{"name", spanner::Value(std::move(singer_info))}});
auto dml_result = client.ExecuteDml(txn, std::move(sql));
if (!dml_result) return std::move(dml_result).status();
rows_modified = dml_result->RowsModified();
return spanner::Mutations{};
});
if (!commit_result) throw std::move(commit_result).status();
std::cout << rows_modified
<< " update was successful [spanner_dml_structs]\n";
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;
public class UpdateUsingDmlWithStructCoreAsyncSample
{
public async Task<int> UpdateUsingDmlWithStructCoreAsync(string projectId, string instanceId, string databaseId)
{
var nameStruct = new SpannerStruct
{
{ "FirstName", SpannerDbType.String, "Timothy" },
{ "LastName", SpannerDbType.String, "Campbell" }
};
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
using var cmd = connection.CreateDmlCommand("UPDATE Singers SET LastName = 'Grant' WHERE STRUCT<FirstName STRING, LastName STRING>(FirstName, LastName) = @name");
cmd.Parameters.Add("name", nameStruct.GetSpannerDbType(), nameStruct);
int rowCount = await cmd.ExecuteNonQueryAsync();
Console.WriteLine($"{rowCount} row(s) updated...");
return rowCount;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
)
func updateUsingDMLStruct(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
type name struct {
FirstName string
LastName string
}
var singerInfo = name{"Timothy", "Campbell"}
stmt := spanner.Statement{
SQL: `Update Singers Set LastName = 'Grant'
WHERE STRUCT<FirstName String, LastName String>(Firstname, LastName) = @name`,
Params: map[string]interface{}{"name": singerInfo},
}
rowCount, err := txn.Update(ctx, stmt)
if err != nil {
return err
}
fmt.Fprintf(w, "%d record(s) inserted.\n", rowCount)
return nil
})
return err
}
Java
static void updateUsingDmlWithStruct(DatabaseClient dbClient) {
Struct name =
Struct.newBuilder().set("FirstName").to("Timothy").set("LastName").to("Campbell").build();
Statement s =
Statement.newBuilder(
"UPDATE Singers SET LastName = 'Grant' "
+ "WHERE STRUCT<FirstName STRING, LastName STRING>(FirstName, LastName) "
+ "= @name")
.bind("name")
.to(name)
.build();
dbClient
.readWriteTransaction()
.run(transaction -> {
long rowCount = transaction.executeUpdate(s);
System.out.printf("%d record updated.\n", rowCount);
return null;
});
}Node.js
// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');
const nameStruct = Spanner.struct({
FirstName: 'Timothy',
LastName: 'Campbell',
});
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rowCount] = await transaction.runUpdate({
sql: `UPDATE Singers SET LastName = 'Grant'
WHERE STRUCT<FirstName STRING, LastName STRING>(FirstName, LastName) = @name`,
params: {
name: nameStruct,
},
});
console.log(`Successfully updated ${rowCount} record.`);
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});PHP
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Database;
use Google\Cloud\Spanner\Transaction;
use Google\Cloud\Spanner\StructType;
use Google\Cloud\Spanner\StructValue;
/**
* Update data with a DML statement using Structs.
*
* The database and table must already exist and can be created using
* `create_database`.
* Example:
* ```
* insert_data($instanceId, $databaseId);
* ```
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function update_data_with_dml_structs(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$database->runTransaction(function (Transaction $t) {
$nameValue = (new StructValue)
->add('FirstName', 'Timothy')
->add('LastName', 'Campbell');
$nameType = (new StructType)
->add('FirstName', Database::TYPE_STRING)
->add('LastName', Database::TYPE_STRING);
$rowCount = $t->executeUpdate(
"UPDATE Singers SET LastName = 'Grant' "
. 'WHERE STRUCT<FirstName STRING, LastName STRING>(FirstName, LastName) '
. '= @name',
[
'parameters' => [
'name' => $nameValue
],
'types' => [
'name' => $nameType
]
]);
$t->commit();
printf('Updated %d row(s).' . PHP_EOL, $rowCount);
});
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
record_type = param_types.Struct(
[
param_types.StructField("FirstName", param_types.STRING),
param_types.StructField("LastName", param_types.STRING),
]
)
record_value = ("Timothy", "Campbell")
def write_with_struct(transaction):
row_ct = transaction.execute_update(
"UPDATE Singers SET LastName = 'Grant' "
"WHERE STRUCT<FirstName STRING, LastName STRING>"
"(FirstName, LastName) = @name",
params={"name": record_value},
param_types={"name": record_type},
)
print("{} record(s) updated.".format(row_ct))
database.run_in_transaction(write_with_struct)Ruby
# project_id = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"
require "google/cloud/spanner"
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
row_count = 0
name_struct = { FirstName: "Timothy", LastName: "Campbell" }
client.transaction do |transaction|
row_count = transaction.execute_update(
"UPDATE Singers SET LastName = 'Grant'
WHERE STRUCT<FirstName STRING, LastName STRING>(FirstName, LastName) = @name",
params: { name: name_struct }
)
end
puts "#{row_count} record updated."Memodifikasi data dengan pernyataan DML yang ditampilkan
Klausa THEN RETURN (database dialek GoogleSQL) atau klausa RETURNING (database dialek PostgreSQL) ditujukan untuk skenario saat Anda ingin mengambil data dari baris yang dimodifikasi. Hal ini sangat berguna ketika Anda ingin melihat nilai yang belum ditentukan dalam pernyataan DML, nilai default, atau kolom yang dihasilkan.
Untuk menjalankan pernyataan DML yang ditampilkan menggunakan library klien:
- Buat transaksi baca-tulis.
- Panggil metode library klien untuk eksekusi kueri dan teruskan pernyataan DML yang ditampilkan untuk mendapatkan hasilnya.
Contoh kode berikut menyisipkan baris baru ke dalam tabel Singers, dan
menampilkan kolom yang dihasilkan FullName dari data yang disisipkan.
GoogleSQL
C++
void InsertUsingDmlReturning(google::cloud::spanner::Client client) {
// Insert records into SINGERS table and return the generated column
// FullName of the inserted records using `THEN RETURN FullName`.
auto commit = client.Commit(
[&client](google::cloud::spanner::Transaction txn)
-> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
auto sql = google::cloud::spanner::SqlStatement(R"""(
INSERT INTO Singers (SingerId, FirstName, LastName)
VALUES (12, 'Melissa', 'Garcia'),
(13, 'Russell', 'Morales'),
(14, 'Jacqueline', 'Long'),
(15, 'Dylan', 'Shaw')
THEN RETURN FullName
)""");
using RowType = std::tuple<std::string>;
auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
// Note: This mutator might be re-run, or its effects discarded, so
// changing non-transactional state (e.g., by producing output) is,
// in general, not something to be imitated.
for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
if (!row) return std::move(row).status();
std::cout << "FullName: " << std::get<0>(*row) << "\n";
}
std::cout << "Inserted row(s) count: " << rows.RowsModified() << "\n";
return google::cloud::spanner::Mutations{};
});
if (!commit) throw std::move(commit).status();
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
public class InsertUsingDmlReturningAsyncSample
{
public async Task<List<string>> InsertUsingDmlReturningAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
// Insert records into the SINGERS table and return the
// generated column FullName of the inserted records using
// 'THEN RETURN FullName'.
// It is also possible to return all columns of all the
// inserted records by using 'THEN RETURN *'.
using var cmd = connection.CreateDmlCommand(
@"INSERT INTO Singers(SingerId, FirstName, LastName) VALUES
(6, 'Melissa', 'Garcia'),
(7, 'Russell', 'Morales'),
(8, 'Jacqueline', 'Long'),
(9, 'Dylan', 'Shaw') THEN RETURN FullName");
var reader = await cmd.ExecuteReaderAsync();
var insertedSingerNames = new List<string>();
while (await reader.ReadAsync())
{
insertedSingerNames.Add(reader.GetFieldValue<string>("FullName"));
}
Console.WriteLine($"{insertedSingerNames.Count} row(s) inserted...");
return insertedSingerNames;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
func insertUsingDMLReturning(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
// Insert records into the SINGERS table and returns the
// generated column FullName of the inserted records using
// 'THEN RETURN FullName'.
// It is also possible to return all columns of all the
// inserted records by using 'THEN RETURN *'.
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `INSERT INTO Singers (SingerId, FirstName, LastName)
VALUES (21, 'Melissa', 'Garcia'),
(22, 'Russell', 'Morales'),
(23, 'Jacqueline', 'Long'),
(24, 'Dylan', 'Shaw')
THEN RETURN FullName`,
}
iter := txn.Query(ctx, stmt)
defer iter.Stop()
for {
row, err := iter.Next()
if err == iterator.Done {
break
}
if err != nil {
return err
}
var fullName string
if err := row.Columns(&fullName); err != nil {
return err
}
fmt.Fprintf(w, "%s\n", fullName)
}
fmt.Fprintf(w, "%d record(s) inserted.\n", iter.RowCount)
return nil
})
return err
}
Java
import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
public class InsertUsingDmlReturningSample {
static void insertUsingDmlReturning() {
// TODO(developer): Replace these variables before running the sample.
final String projectId = "my-project";
final String instanceId = "my-instance";
final String databaseId = "my-database";
insertUsingDmlReturning(projectId, instanceId, databaseId);
}
static void insertUsingDmlReturning(String projectId, String instanceId, String databaseId) {
try (Spanner spanner =
SpannerOptions.newBuilder()
.setProjectId(projectId)
.build()
.getService()) {
final DatabaseClient dbClient =
spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
// Insert records into the SINGERS table and returns the
// generated column FullName of the inserted records using
// ‘THEN RETURN FullName’.
// It is also possible to return all columns of all the
// inserted records by using ‘THEN RETURN *’.
dbClient
.readWriteTransaction()
.run(
transaction -> {
String sql =
"INSERT INTO Singers (SingerId, FirstName, LastName) VALUES "
+ "(12, 'Melissa', 'Garcia'), "
+ "(13, 'Russell', 'Morales'), "
+ "(14, 'Jacqueline', 'Long'), "
+ "(15, 'Dylan', 'Shaw') THEN RETURN FullName";
// readWriteTransaction.executeQuery(..) API should be used for executing
// DML statements with RETURNING clause.
try (ResultSet resultSet = transaction.executeQuery(Statement.of(sql))) {
while (resultSet.next()) {
System.out.println(resultSet.getString(0));
}
System.out.printf(
"Inserted row(s) count: %d\n", resultSet.getStats().getRowCountExact());
}
return null;
});
}
}
}Node.js
// Imports the Google Cloud client library.
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
function insertUsingDmlReturning(instanceId, databaseId) {
// Gets a reference to a Cloud Spanner instance and database.
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rows, stats] = await transaction.run({
sql: 'INSERT Singers (SingerId, FirstName, LastName) VALUES (@id, @firstName, @lastName) THEN RETURN FullName',
params: {
id: 18,
firstName: 'Virginia',
lastName: 'Watson',
},
});
const rowCount = Math.floor(stats[stats.rowCount]);
console.log(
`Successfully inserted ${rowCount} record into the Singers table.`
);
rows.forEach(row => {
console.log(row.toJSON().FullName);
});
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});
}
insertUsingDmlReturning(instanceId, databaseId);PHP
use Google\Cloud\Spanner\SpannerClient;
/**
* Inserts sample data into the given database using DML returning.
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function insert_dml_returning(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
// Insert records into SINGERS table and returns the generated column
// FullName of the inserted records using ‘THEN RETURN FullName’. It is also
// possible to return all columns of all the inserted records by using
// ‘THEN RETURN *’.
$sql = 'INSERT INTO Singers (SingerId, FirstName, LastName) '
. "VALUES (12, 'Melissa', 'Garcia'), "
. "(13, 'Russell', 'Morales'), "
. "(14, 'Jacqueline', 'Long'), "
. "(15, 'Dylan', 'Shaw') "
. 'THEN RETURN FullName';
$transaction = $database->transaction();
$result = $transaction->execute($sql);
foreach ($result->rows() as $row) {
printf(
'%s inserted.' . PHP_EOL,
$row['FullName'],
);
}
printf(
'Inserted row(s) count: %d' . PHP_EOL,
$result->stats()['rowCountExact']
);
$transaction->commit();
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
# Insert records into the SINGERS table and returns the
# generated column FullName of the inserted records using
# 'THEN RETURN FullName'.
# It is also possible to return all columns of all the
# inserted records by using 'THEN RETURN *'.
def insert_singers(transaction):
results = transaction.execute_sql(
"INSERT INTO Singers (SingerId, FirstName, LastName) VALUES "
"(21, 'Luann', 'Chizoba'), "
"(22, 'Denis', 'Patricio'), "
"(23, 'Felxi', 'Ronan'), "
"(24, 'Dominik', 'Martyna') "
"THEN RETURN FullName"
)
for result in results:
print("FullName: {}".format(*result))
print("{} record(s) inserted.".format(results.stats.row_count_exact))
database.run_in_transaction(insert_singers)Ruby
require "google/cloud/spanner"
##
# This is a snippet for showcasing how to use DML return feature with insert
# operation.
#
# @param project_id [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_insert_dml_returning project_id:, instance_id:, database_id:
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
client.transaction do |transaction|
# Insert records into the SINGERS table and returns the generated column
# FullName of the inserted records using ‘THEN RETURN FullName’.
# It is also possible to return all columns of all the inserted records
# by using ‘THEN RETURN *’.
results = transaction.execute_query "INSERT INTO Singers (SingerId, FirstName, LastName)
VALUES (12, 'Melissa', 'Garcia'), (13, 'Russell', 'Morales'), (14, 'Jacqueline', 'Long'), (15, 'Dylan', 'Shaw')
THEN RETURN FullName"
results.rows.each do |row|
puts "Inserted singers with FullName: #{row[:FullName]}"
end
puts "Inserted row(s) count: #{results.row_count}"
end
end
PostgreSQL
C++
void InsertUsingDmlReturning(google::cloud::spanner::Client client) {
// Insert records into SINGERS table and return the generated column
// FullName of the inserted records using `RETURNING FullName`.
auto commit = client.Commit(
[&client](google::cloud::spanner::Transaction txn)
-> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
auto sql = google::cloud::spanner::SqlStatement(R"""(
INSERT INTO Singers (SingerId, FirstName, LastName)
VALUES (12, 'Melissa', 'Garcia'),
(13, 'Russell', 'Morales'),
(14, 'Jacqueline', 'Long'),
(15, 'Dylan', 'Shaw')
RETURNING FullName
)""");
using RowType = std::tuple<std::string>;
auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
if (!row) return std::move(row).status();
std::cout << "FullName: " << std::get<0>(*row) << "\n";
}
std::cout << "Inserted row(s) count: " << rows.RowsModified() << "\n";
return google::cloud::spanner::Mutations{};
});
if (!commit) throw std::move(commit).status();
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
public class InsertUsingDmlReturningAsyncPostgresSample
{
public async Task<List<string>> InsertUsingDmlReturningAsyncPostgres(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
// Insert records into SINGERS table and return the
// generated column FullName of the inserted records
// using 'RETURNING FullName'.
// It is also possible to return all columns of all the
// inserted records by using 'RETURNING *'.
using var cmd = connection.CreateDmlCommand(
@"INSERT INTO Singers(SingerId, FirstName, LastName) VALUES
(6, 'Melissa', 'Garcia'),
(7, 'Russell', 'Morales'),
(8, 'Jacqueline', 'Long'),
(9, 'Dylan', 'Shaw') RETURNING FullName");
var reader = await cmd.ExecuteReaderAsync();
var insertedSingerNames = new List<string>();
while (await reader.ReadAsync())
{
insertedSingerNames.Add(reader.GetFieldValue<string>("fullname"));
}
Console.WriteLine($"{insertedSingerNames.Count} row(s) inserted...");
return insertedSingerNames;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
func pgInsertUsingDMLReturning(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
// Insert records into the SINGERS table and returns the
// generated column FullName of the inserted records using
// 'RETURNING FullName'.
// It is also possible to return all columns of all the
// inserted records by using 'RETURNING *'.
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `INSERT INTO Singers (SingerId, FirstName, LastName)
VALUES (21, 'Melissa', 'Garcia'),
(22, 'Russell', 'Morales'),
(23, 'Jacqueline', 'Long'),
(24, 'Dylan', 'Shaw')
RETURNING FullName`,
}
iter := txn.Query(ctx, stmt)
defer iter.Stop()
for {
row, err := iter.Next()
if err == iterator.Done {
break
}
if err != nil {
return err
}
var fullName string
if err := row.Columns(&fullName); err != nil {
return err
}
fmt.Fprintf(w, "%s\n", fullName)
}
fmt.Fprintf(w, "%d record(s) inserted.\n", iter.RowCount)
return nil
})
return err
}
Java
import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
public class PgInsertUsingDmlReturningSample {
static void insertUsingDmlReturning() {
// TODO(developer): Replace these variables before running the sample.
final String projectId = "my-project";
final String instanceId = "my-instance";
final String databaseId = "my-database";
insertUsingDmlReturning(projectId, instanceId, databaseId);
}
static void insertUsingDmlReturning(String projectId, String instanceId, String databaseId) {
try (Spanner spanner =
SpannerOptions.newBuilder()
.setProjectId(projectId)
.build()
.getService()) {
final DatabaseClient dbClient =
spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
// Insert records into SINGERS table and returns the
// generated column FullName of the inserted records
// using ‘RETURNING FullName’.
// It is also possible to return all columns of all the
// inserted records by using ‘RETURNING *’.
dbClient
.readWriteTransaction()
.run(
transaction -> {
String sql =
"INSERT INTO Singers (SingerId, FirstName, LastName) VALUES "
+ "(12, 'Melissa', 'Garcia'), "
+ "(13, 'Russell', 'Morales'), "
+ "(14, 'Jacqueline', 'Long'), "
+ "(15, 'Dylan', 'Shaw') RETURNING FullName";
// readWriteTransaction.executeQuery(..) API should be used for executing
// DML statements with RETURNING clause.
try (ResultSet resultSet = transaction.executeQuery(Statement.of(sql))) {
while (resultSet.next()) {
System.out.println(resultSet.getString(0));
}
System.out.printf(
"Inserted row(s) count: %d\n", resultSet.getStats().getRowCountExact());
}
return null;
});
}
}
}Node.js
// Imports the Google Cloud client library.
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
function pgInsertUsingDmlReturning(instanceId, databaseId) {
// Gets a reference to a Cloud Spanner instance and database.
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rows, stats] = await transaction.run({
sql: 'INSERT Into Singers (SingerId, FirstName, LastName) VALUES ($1, $2, $3) RETURNING FullName',
params: {
p1: 18,
p2: 'Virginia',
p3: 'Watson',
},
});
const rowCount = Math.floor(stats[stats.rowCount]);
console.log(
`Successfully inserted ${rowCount} record into the Singers table.`
);
rows.forEach(row => {
console.log(row.toJSON().fullname);
});
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});
}
pgInsertUsingDmlReturning(instanceId, databaseId);PHP
use Google\Cloud\Spanner\SpannerClient;
/**
* Inserts sample data into the given postgresql database using DML returning.
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function pg_insert_dml_returning(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
// Insert records into SINGERS table and returns the generated column
// FullName of the inserted records using ‘RETURNING FullName’. It is also
// possible to return all columns of all the inserted records by using
// ‘RETURNING *’.
$sql = 'INSERT INTO Singers (Singerid, FirstName, LastName) '
. "VALUES (12, 'Melissa', 'Garcia'), "
. "(13, 'Russell', 'Morales'), "
. "(14, 'Jacqueline', 'Long'), "
. "(15, 'Dylan', 'Shaw') "
. 'RETURNING FullName';
$transaction = $database->transaction();
$result = $transaction->execute($sql);
foreach ($result->rows() as $row) {
printf(
'%s inserted.' . PHP_EOL,
$row['fullname'],
);
}
printf(
'Inserted row(s) count: %d' . PHP_EOL,
$result->stats()['rowCountExact']
);
$transaction->commit();
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
# Insert records into the SINGERS table and returns the
# generated column FullName of the inserted records using
# 'RETURNING FullName'.
# It is also possible to return all columns of all the
# inserted records by using 'RETURNING *'.
def insert_singers(transaction):
results = transaction.execute_sql(
"INSERT INTO Singers (SingerId, FirstName, LastName) VALUES "
"(21, 'Luann', 'Chizoba'), "
"(22, 'Denis', 'Patricio'), "
"(23, 'Felxi', 'Ronan'), "
"(24, 'Dominik', 'Martyna') "
"RETURNING FullName"
)
for result in results:
print("FullName: {}".format(*result))
print("{} record(s) inserted.".format(results.stats.row_count_exact))
database.run_in_transaction(insert_singers)Ruby
require "google/cloud/spanner"
##
# This is a snippet for showcasing how to use DML return feature with insert
# operation in PostgreSql.
#
# @param project_id [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_postgresql_insert_dml_returning project_id:, instance_id:, database_id:
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
client.transaction do |transaction|
# Insert records into SINGERS table and returns the generated column
# FullName of the inserted records using ‘RETURNING FullName’.
# It is also possible to return all columns of all the inserted
# records by using ‘RETURNING *’.
results = transaction.execute_query "INSERT INTO Singers (SingerId, FirstName, LastName)
VALUES (12, 'Melissa', 'Garcia'), (13, 'Russell', 'Morales'), (14, 'Jacqueline', 'Long'), (15, 'Dylan', 'Shaw')
RETURNING FullName"
results.rows.each do |row|
puts "Inserted singers with FullName: #{row[:fullname]}"
end
puts "Inserted row(s) count: #{results.row_count}"
end
end
Contoh kode berikut memperbarui kolom MarketingBudget pada tabel Albums
berdasarkan klausa WHERE, dan menampilkan kolom MarketingBudget
yang dimodifikasi dari data yang diperbarui.
GoogleSQL
C++
void UpdateUsingDmlReturning(google::cloud::spanner::Client client) {
// Update MarketingBudget column for records satisfying a particular
// condition and return the modified MarketingBudget column of the
// updated records using `THEN RETURN MarketingBudget`.
auto commit = client.Commit(
[&client](google::cloud::spanner::Transaction txn)
-> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
auto sql = google::cloud::spanner::SqlStatement(R"""(
UPDATE Albums SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 AND AlbumId = 1
THEN RETURN MarketingBudget
)""");
using RowType = std::tuple<absl::optional<std::int64_t>>;
auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
// Note: This mutator might be re-run, or its effects discarded, so
// changing non-transactional state (e.g., by producing output) is,
// in general, not something to be imitated.
for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
if (!row) return std::move(row).status();
std::cout << "MarketingBudget: ";
if (std::get<0>(*row).has_value()) {
std::cout << *std::get<0>(*row);
} else {
std::cout << "NULL";
}
std::cout << "\n";
}
std::cout << "Updated row(s) count: " << rows.RowsModified() << "\n";
return google::cloud::spanner::Mutations{};
});
if (!commit) throw std::move(commit).status();
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
public class UpdateUsingDmlReturningAsyncSample
{
public async Task<List<long>> UpdateUsingDmlReturningAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
// Update MarketingBudget column for records satisfying
// a particular condition and return the modified
// MarketingBudget column of the updated records using
// 'THEN RETURN MarketingBudget'.
// It is also possible to return all columns of all the
// updated records by using 'THEN RETURN *'.
using var cmd = connection.CreateDmlCommand("UPDATE Albums SET MarketingBudget = MarketingBudget * 2 WHERE SingerId = 1 and AlbumId = 1 THEN RETURN MarketingBudget");
var reader = await cmd.ExecuteReaderAsync();
var updatedMarketingBudgets = new List<long>();
while (await reader.ReadAsync())
{
updatedMarketingBudgets.Add(reader.GetFieldValue<long>("MarketingBudget"));
}
Console.WriteLine($"{updatedMarketingBudgets.Count} row(s) updated...");
return updatedMarketingBudgets;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
func updateUsingDMLReturning(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
// Update MarketingBudget column for records satisfying
// a particular condition and returns the modified
// MarketingBudget column of the updated records using
// 'THEN RETURN MarketingBudget'.
// It is also possible to return all columns of all the
// updated records by using 'THEN RETURN *'.
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `UPDATE Albums
SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 1
THEN RETURN MarketingBudget`,
}
iter := txn.Query(ctx, stmt)
defer iter.Stop()
for {
row, err := iter.Next()
if err == iterator.Done {
break
}
if err != nil {
return err
}
var marketingBudget int64
if err := row.Columns(&marketingBudget); err != nil {
return err
}
fmt.Fprintf(w, "%d\n", marketingBudget)
}
fmt.Fprintf(w, "%d record(s) updated.\n", iter.RowCount)
return nil
})
return err
}
Java
import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
public class UpdateUsingDmlReturningSample {
static void updateUsingDmlReturning() {
// TODO(developer): Replace these variables before running the sample.
final String projectId = "my-project";
final String instanceId = "my-instance";
final String databaseId = "my-database";
updateUsingDmlReturning(projectId, instanceId, databaseId);
}
static void updateUsingDmlReturning(String projectId, String instanceId, String databaseId) {
try (Spanner spanner =
SpannerOptions.newBuilder()
.setProjectId(projectId)
.build()
.getService()) {
final DatabaseClient dbClient =
spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
// Update MarketingBudget column for records satisfying
// a particular condition and returns the modified
// MarketingBudget column of the updated records using
// ‘THEN RETURN MarketingBudget’.
// It is also possible to return all columns of all the
// updated records by using ‘THEN RETURN *’.
dbClient
.readWriteTransaction()
.run(
transaction -> {
String sql =
"UPDATE Albums "
+ "SET MarketingBudget = MarketingBudget * 2 "
+ "WHERE SingerId = 1 and AlbumId = 1 "
+ "THEN RETURN MarketingBudget";
// readWriteTransaction.executeQuery(..) API should be used for executing
// DML statements with RETURNING clause.
try (ResultSet resultSet = transaction.executeQuery(Statement.of(sql))) {
while (resultSet.next()) {
System.out.printf("%d\n", resultSet.getLong(0));
}
System.out.printf(
"Updated row(s) count: %d\n", resultSet.getStats().getRowCountExact());
}
return null;
});
}
}
}Node.js
// Imports the Google Cloud client library.
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
function updateUsingDmlReturning(instanceId, databaseId) {
// Gets a reference to a Cloud Spanner instance and database.
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rows, stats] = await transaction.run({
sql: 'UPDATE Albums SET MarketingBudget = 2000000 WHERE SingerId = 1 and AlbumId = 1 THEN RETURN MarketingBudget',
});
const rowCount = Math.floor(stats[stats.rowCount]);
console.log(
`Successfully updated ${rowCount} record into the Albums table.`
);
rows.forEach(row => {
console.log(row.toJSON().MarketingBudget);
});
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});
}
updateUsingDmlReturning(instanceId, databaseId);PHP
use Google\Cloud\Spanner\SpannerClient;
/**
* Update the given database using DML returning.
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function update_dml_returning(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$transaction = $database->transaction();
// Update MarketingBudget column for records satisfying a particular
// condition and returns the modified MarketingBudget column of the updated
// records using ‘THEN RETURN MarketingBudget’. It is also possible to return
// all columns of all the updated records by using ‘THEN RETURN *’.
$result = $transaction->execute(
'UPDATE Albums '
. 'SET MarketingBudget = MarketingBudget * 2 '
. 'WHERE SingerId = 1 and AlbumId = 1 '
. 'THEN RETURN MarketingBudget'
);
foreach ($result->rows() as $row) {
printf('MarketingBudget: %s' . PHP_EOL, $row['MarketingBudget']);
}
printf(
'Updated row(s) count: %d' . PHP_EOL,
$result->stats()['rowCountExact']
);
$transaction->commit();
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
# Update MarketingBudget column for records satisfying
# a particular condition and returns the modified
# MarketingBudget column of the updated records using
# 'THEN RETURN MarketingBudget'.
# It is also possible to return all columns of all the
# updated records by using 'THEN RETURN *'.
def update_albums(transaction):
results = transaction.execute_sql(
"UPDATE Albums "
"SET MarketingBudget = MarketingBudget * 2 "
"WHERE SingerId = 1 and AlbumId = 1 "
"THEN RETURN MarketingBudget"
)
for result in results:
print("MarketingBudget: {}".format(*result))
print("{} record(s) updated.".format(results.stats.row_count_exact))
database.run_in_transaction(update_albums)Ruby
require "google/cloud/spanner"
##
# This is a snippet for showcasing how to use DML return feature with update
# operation.
#
# @param project_id [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_update_dml_returning project_id:, instance_id:, database_id:
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
client.transaction do |transaction|
# Update MarketingBudget column for records satisfying a particular
# condition and returns the modified MarketingBudget column of the
# updated records using ‘THEN RETURN MarketingBudget’.
#
# It is also possible to return all columns of all the updated records
# by using ‘THEN RETURN *’.
results = transaction.execute_query "UPDATE Albums SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 1
THEN RETURN MarketingBudget"
results.rows.each do |row|
puts "Updated Album with MarketingBudget: #{row[:MarketingBudget]}"
end
puts "Updated row(s) count: #{results.row_count}"
end
end
PostgreSQL
C++
void UpdateUsingDmlReturning(google::cloud::spanner::Client client) {
// Update MarketingBudget column for records satisfying a particular
// condition and return the modified MarketingBudget column of the
// updated records using `RETURNING MarketingBudget`.
auto commit = client.Commit(
[&client](google::cloud::spanner::Transaction txn)
-> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
auto sql = google::cloud::spanner::SqlStatement(R"""(
UPDATE Albums SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 AND AlbumId = 1
RETURNING MarketingBudget
)""");
using RowType = std::tuple<absl::optional<std::int64_t>>;
auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
if (!row) return std::move(row).status();
std::cout << "MarketingBudget: ";
if (std::get<0>(*row).has_value()) {
std::cout << *std::get<0>(*row);
} else {
std::cout << "NULL";
}
std::cout << "\n";
}
std::cout << "Updated row(s) count: " << rows.RowsModified() << "\n";
return google::cloud::spanner::Mutations{};
});
if (!commit) throw std::move(commit).status();
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
public class UpdateUsingDmlReturningAsyncPostgresSample
{
public async Task<List<long>> UpdateUsingDmlReturningAsyncPostgres(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
// Update MarketingBudget column for records satisfying
// a particular condition and return the modified
// MarketingBudget column of the updated records using
// 'RETURNING MarketingBudget'.
// It is also possible to return all columns of all the
// updated records by using 'RETURNING *'.
using var cmd = connection.CreateDmlCommand("UPDATE Albums SET MarketingBudget = MarketingBudget * 2 WHERE SingerId = 14 and AlbumId = 20 RETURNING MarketingBudget");
var reader = await cmd.ExecuteReaderAsync();
var updatedMarketingBudgets = new List<long>();
while (await reader.ReadAsync())
{
updatedMarketingBudgets.Add(reader.GetFieldValue<long>("marketingbudget"));
}
Console.WriteLine($"{updatedMarketingBudgets.Count} row(s) updated...");
return updatedMarketingBudgets;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
func pgUpdateUsingDMLReturning(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
// Update MarketingBudget column for records satisfying
// a particular condition and returns the modified
// MarketingBudget column of the updated records using
// 'RETURNING MarketingBudget'.
// It is also possible to return all columns of all the
// updated records by using 'RETURNING *'.
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `UPDATE Albums
SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 1
RETURNING MarketingBudget`,
}
iter := txn.Query(ctx, stmt)
defer iter.Stop()
for {
row, err := iter.Next()
if err == iterator.Done {
break
}
if err != nil {
return err
}
var marketingBudget int64
if err := row.Columns(&marketingBudget); err != nil {
return err
}
fmt.Fprintf(w, "%d\n", marketingBudget)
}
fmt.Fprintf(w, "%d record(s) updated.\n", iter.RowCount)
return nil
})
return err
}
Java
import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
public class PgUpdateUsingDmlReturningSample {
static void updateUsingDmlReturning() {
// TODO(developer): Replace these variables before running the sample.
final String projectId = "my-project";
final String instanceId = "my-instance";
final String databaseId = "my-database";
updateUsingDmlReturning(projectId, instanceId, databaseId);
}
static void updateUsingDmlReturning(String projectId, String instanceId, String databaseId) {
try (Spanner spanner =
SpannerOptions.newBuilder()
.setProjectId(projectId)
.build()
.getService()) {
final DatabaseClient dbClient =
spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
// Update MarketingBudget column for records satisfying
// a particular condition and returns the modified
// MarketingBudget column of the updated records using
// ‘RETURNING MarketingBudget’.
// It is also possible to return all columns of all the
// updated records by using ‘RETURNING *’.
dbClient
.readWriteTransaction()
.run(
transaction -> {
String sql =
"UPDATE Albums "
+ "SET MarketingBudget = MarketingBudget * 2 "
+ "WHERE SingerId = 1 and AlbumId = 1 "
+ "RETURNING MarketingBudget";
// readWriteTransaction.executeQuery(..) API should be used for executing
// DML statements with RETURNING clause.
try (ResultSet resultSet = transaction.executeQuery(Statement.of(sql))) {
while (resultSet.next()) {
System.out.printf("%d\n", resultSet.getLong(0));
}
System.out.printf(
"Updated row(s) count: %d\n", resultSet.getStats().getRowCountExact());
}
return null;
});
}
}
}Node.js
// Imports the Google Cloud client library.
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
function pgUpdateUsingDmlReturning(instanceId, databaseId) {
// Gets a reference to a Cloud Spanner instance and database.
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rows, stats] = await transaction.run({
sql: 'UPDATE singers SET FirstName = $1, LastName = $2 WHERE singerid = $3 RETURNING FullName',
params: {
p1: 'Virginia1',
p2: 'Watson1',
p3: 18,
},
});
const rowCount = Math.floor(stats[stats.rowCount]);
console.log(
`Successfully updated ${rowCount} record into the Singers table.`
);
rows.forEach(row => {
console.log(row.toJSON().fullname);
});
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});
}
pgUpdateUsingDmlReturning(instanceId, databaseId);PHP
use Google\Cloud\Spanner\SpannerClient;
/**
* Update the given postgresql database using DML returning.
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function pg_update_dml_returning(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$transaction = $database->transaction();
// Update MarketingBudget column for records satisfying a particular
// condition and returns the modified MarketingBudget column of the updated
// records using ‘RETURNING MarketingBudget’. It is also possible to return
// all columns of all the updated records by using ‘RETURNING *’.
$result = $transaction->execute(
'UPDATE Albums '
. 'SET MarketingBudget = MarketingBudget * 2 '
. 'WHERE SingerId = 1 and AlbumId = 1'
. 'RETURNING MarketingBudget'
);
foreach ($result->rows() as $row) {
printf('MarketingBudget: %s' . PHP_EOL, $row['marketingbudget']);
}
printf(
'Updated row(s) count: %d' . PHP_EOL,
$result->stats()['rowCountExact']
);
$transaction->commit();
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
# Update MarketingBudget column for records satisfying
# a particular condition and returns the modified
# MarketingBudget column of the updated records using
# 'RETURNING MarketingBudget'.
# It is also possible to return all columns of all the
# updated records by using 'RETURNING *'.
def update_albums(transaction):
results = transaction.execute_sql(
"UPDATE Albums "
"SET MarketingBudget = MarketingBudget * 2 "
"WHERE SingerId = 1 and AlbumId = 1 "
"RETURNING MarketingBudget"
)
for result in results:
print("MarketingBudget: {}".format(*result))
print("{} record(s) updated.".format(results.stats.row_count_exact))
database.run_in_transaction(update_albums)Ruby
require "google/cloud/spanner"
##
# This is a snippet for showcasing how to use DML return feature with update
# operation in PostgreSql.
#
# @param project_id [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_postgresql_update_dml_returning project_id:, instance_id:, database_id:
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
client.transaction do |transaction|
# Update MarketingBudget column for records satisfying a particular
# condition and returns the modified MarketingBudget column of the
# updated records using ‘RETURNING MarketingBudget’.
# It is also possible to return all columns of all the updated records
# by using ‘RETURNING *’.
results = transaction.execute_query "UPDATE Albums SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 1
RETURNING MarketingBudget"
results.rows.each do |row|
puts "Updated Albums with MarketingBudget: #{row[:marketingbudget]}"
end
puts "Updated row(s) count: #{results.row_count}"
end
end
Contoh kode berikut menghapus semua baris dalam tabel Singers dengan kolom FirstName adalah Alice, dan menampilkan kolom SingerId dan FullName dari kumpulan data yang dihapus.
GoogleSQL
C++
void DeleteUsingDmlReturning(google::cloud::spanner::Client client) {
// Delete records from SINGERS table satisfying a particular condition
// and return the SingerId and FullName column of the deleted records
// using `THEN RETURN SingerId, FullName'.
auto commit = client.Commit(
[&client](google::cloud::spanner::Transaction txn)
-> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
auto sql = google::cloud::spanner::SqlStatement(R"""(
DELETE FROM Singers
WHERE FirstName = 'Alice'
THEN RETURN SingerId, FullName
)""");
using RowType = std::tuple<std::int64_t, std::string>;
auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
// Note: This mutator might be re-run, or its effects discarded, so
// changing non-transactional state (e.g., by producing output) is,
// in general, not something to be imitated.
for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
if (!row) return std::move(row).status();
std::cout << "SingerId: " << std::get<0>(*row) << " ";
std::cout << "FullName: " << std::get<1>(*row) << "\n";
}
std::cout << "Deleted row(s) count: " << rows.RowsModified() << "\n";
return google::cloud::spanner::Mutations{};
});
if (!commit) throw std::move(commit).status();
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
public class DeleteUsingDmlReturningAsyncSample
{
public async Task<List<string>> DeleteUsingDmlReturningAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
// Delete records from SINGERS table satisfying a
// particular condition and return the SingerId
// and FullName column of the deleted records using
// 'THEN RETURN SingerId, FullName'.
// It is also possible to return all columns of all the
// deleted records by using 'THEN RETURN *'.
using var cmd = connection.CreateDmlCommand("DELETE FROM Singers WHERE FirstName = 'Alice' THEN RETURN SingerId, FullName");
var reader = await cmd.ExecuteReaderAsync();
var deletedSingerNames = new List<string>();
while (await reader.ReadAsync())
{
deletedSingerNames.Add(reader.GetFieldValue<string>("FullName"));
}
Console.WriteLine($"{deletedSingerNames.Count} row(s) deleted...");
return deletedSingerNames;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
func deleteUsingDMLReturning(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
// Delete records from SINGERS table satisfying a
// particular condition and returns the SingerId
// and FullName column of the deleted records using
// 'THEN RETURN SingerId, FullName'.
// It is also possible to return all columns of all the
// deleted records by using 'THEN RETURN *'.
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `DELETE FROM Singers WHERE FirstName = 'Alice'
THEN RETURN SingerId, FullName`,
}
iter := txn.Query(ctx, stmt)
defer iter.Stop()
for {
row, err := iter.Next()
if err == iterator.Done {
break
}
if err != nil {
return err
}
var (
singerID int64
fullName string
)
if err := row.Columns(&singerID, &fullName); err != nil {
return err
}
fmt.Fprintf(w, "%d %s\n", singerID, fullName)
}
fmt.Fprintf(w, "%d record(s) deleted.\n", iter.RowCount)
return nil
})
return err
}
Java
import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
public class DeleteUsingDmlReturningSample {
static void deleteUsingDmlReturningSample() {
// TODO(developer): Replace these variables before running the sample.
final String projectId = "my-project";
final String instanceId = "my-instance";
final String databaseId = "my-database";
deleteUsingDmlReturningSample(projectId, instanceId, databaseId);
}
static void deleteUsingDmlReturningSample(
String projectId, String instanceId, String databaseId) {
try (Spanner spanner =
SpannerOptions.newBuilder()
.setProjectId(projectId)
.build()
.getService()) {
final DatabaseClient dbClient =
spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
// Delete records from SINGERS table satisfying a
// particular condition and returns the SingerId
// and FullName column of the deleted records using
// ‘THEN RETURN SingerId, FullName’.
// It is also possible to return all columns of all the
// deleted records by using ‘THEN RETURN *’.
dbClient
.readWriteTransaction()
.run(
transaction -> {
String sql =
"DELETE FROM Singers WHERE FirstName = 'Alice' THEN RETURN SingerId, FullName";
// readWriteTransaction.executeQuery(..) API should be used for executing
// DML statements with RETURNING clause.
try (ResultSet resultSet = transaction.executeQuery(Statement.of(sql))) {
while (resultSet.next()) {
System.out.printf("%d %s\n", resultSet.getLong(0), resultSet.getString(1));
}
System.out.printf(
"Deleted row(s) count: %d\n", resultSet.getStats().getRowCountExact());
}
return null;
});
}
}
}Node.js
// Imports the Google Cloud client library.
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
function deleteUsingDmlReturning(instanceId, databaseId) {
// Gets a reference to a Cloud Spanner instance and database.
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rows, stats] = await transaction.run({
sql: 'DELETE FROM Singers WHERE SingerId = 18 THEN RETURN FullName',
});
const rowCount = Math.floor(stats[stats.rowCount]);
console.log(
`Successfully deleted ${rowCount} record from the Singers table.`
);
rows.forEach(row => {
console.log(row.toJSON().FullName);
});
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});
}
deleteUsingDmlReturning(instanceId, databaseId);PHP
use Google\Cloud\Spanner\SpannerClient;
/**
* Delete data from the given database using DML returning.
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function delete_dml_returning(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$transaction = $database->transaction();
// Delete records from SINGERS table satisfying a particular condition and
// returns the SingerId and FullName column of the deleted records using
// 'THEN RETURN SingerId, FullName'. It is also possible to return all columns
// of all the deleted records by using 'THEN RETURN *'.
$result = $transaction->execute(
"DELETE FROM Singers WHERE FirstName = 'Alice' "
. 'THEN RETURN SingerId, FullName',
);
foreach ($result->rows() as $row) {
printf(
'%d %s.' . PHP_EOL,
$row['SingerId'],
$row['FullName']
);
}
printf(
'Deleted row(s) count: %d' . PHP_EOL,
$result->stats()['rowCountExact']
);
$transaction->commit();
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
# Delete records from SINGERS table satisfying a
# particular condition and returns the SingerId
# and FullName column of the deleted records using
# 'THEN RETURN SingerId, FullName'.
# It is also possible to return all columns of all the
# deleted records by using 'THEN RETURN *'.
def delete_singers(transaction):
results = transaction.execute_sql(
"DELETE FROM Singers WHERE FirstName = 'David' "
"THEN RETURN SingerId, FullName"
)
for result in results:
print("SingerId: {}, FullName: {}".format(*result))
print("{} record(s) deleted.".format(results.stats.row_count_exact))
database.run_in_transaction(delete_singers)Ruby
require "google/cloud/spanner"
##
# This is a snippet for showcasing how to use DML return feature with delete
# operation.
#
# @param project_id [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_delete_dml_returning project_id:, instance_id:, database_id:
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
client.transaction do |transaction|
# Delete records from SINGERS table satisfying a particular condition and
# returns the SingerId and FullName column of the deleted records using
# ‘THEN RETURN SingerId, FullName’.
# It is also possible to return all columns of all the deleted records
# by using ‘THEN RETURN *’.
results = transaction.execute_query "DELETE FROM Singers WHERE FirstName = 'Alice' THEN RETURN SingerId, FullName"
results.rows.each do |row|
puts "Deleted singer with SingerId: #{row[:SingerId]}, FullName: #{row[:FullName]}"
end
puts "Deleted row(s) count: #{results.row_count}"
end
end
PostgreSQL
C++
void DeleteUsingDmlReturning(google::cloud::spanner::Client client) {
// Delete records from SINGERS table satisfying a particular condition
// and return the SingerId and FullName column of the deleted records
// using `RETURNING SingerId, FullName'.
auto commit = client.Commit(
[&client](google::cloud::spanner::Transaction txn)
-> google::cloud::StatusOr<google::cloud::spanner::Mutations> {
auto sql = google::cloud::spanner::SqlStatement(R"""(
DELETE FROM Singers
WHERE FirstName = 'Alice'
RETURNING SingerId, FullName
)""");
using RowType = std::tuple<std::int64_t, std::string>;
auto rows = client.ExecuteQuery(std::move(txn), std::move(sql));
for (auto& row : google::cloud::spanner::StreamOf<RowType>(rows)) {
if (!row) return std::move(row).status();
std::cout << "SingerId: " << std::get<0>(*row) << " ";
std::cout << "FullName: " << std::get<1>(*row) << "\n";
}
std::cout << "Deleted row(s) count: " << rows.RowsModified() << "\n";
return google::cloud::spanner::Mutations{};
});
if (!commit) throw std::move(commit).status();
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
public class DeleteUsingDmlReturningAsyncPostgresSample
{
public async Task<List<string>> DeleteUsingDmlReturningAsyncPostgres(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
// Delete records from SINGERS table satisfying a
// particular condition and return the SingerId
// and FullName column of the deleted records using
// 'RETURNING SingerId, FullName'.
// It is also possible to return all columns of all the
// deleted records by using 'RETURNING *'.
using var cmd = connection.CreateDmlCommand("DELETE FROM Singers WHERE FirstName = 'Lata' RETURNING SingerId, FullName");
var reader = await cmd.ExecuteReaderAsync();
var deletedSingerNames = new List<string>();
while (await reader.ReadAsync())
{
deletedSingerNames.Add(reader.GetFieldValue<string>("fullname"));
}
Console.WriteLine($"{deletedSingerNames.Count} row(s) deleted...");
return deletedSingerNames;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
func pgDeleteUsingDMLReturning(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
// Delete records from SINGERS table satisfying a
// particular condition and returns the SingerId
// and FullName column of the deleted records using
// 'RETURNING SingerId, FullName'.
// It is also possible to return all columns of all the
// deleted records by using 'RETURNING *'.
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmt := spanner.Statement{
SQL: `DELETE FROM Singers WHERE FirstName = 'Alice'
RETURNING SingerId, FullName`,
}
iter := txn.Query(ctx, stmt)
defer iter.Stop()
for {
row, err := iter.Next()
if err == iterator.Done {
break
}
if err != nil {
return err
}
var (
singerID int64
fullName string
)
if err := row.Columns(&singerID, &fullName); err != nil {
return err
}
fmt.Fprintf(w, "%d %s\n", singerID, fullName)
}
fmt.Fprintf(w, "%d record(s) deleted.\n", iter.RowCount)
return nil
})
return err
}
Java
import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.Spanner;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
public class PgDeleteUsingDmlReturningSample {
static void deleteUsingDmlReturningSample() {
// TODO(developer): Replace these variables before running the sample.
final String projectId = "my-project";
final String instanceId = "my-instance";
final String databaseId = "my-database";
deleteUsingDmlReturningSample(projectId, instanceId, databaseId);
}
static void deleteUsingDmlReturningSample(
String projectId, String instanceId, String databaseId) {
try (Spanner spanner =
SpannerOptions.newBuilder()
.setProjectId(projectId)
.build()
.getService()) {
final DatabaseClient dbClient =
spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
// Delete records from SINGERS table satisfying a
// particular condition and returns the SingerId
// and FullName column of the deleted records using
// ‘RETURNING SingerId, FullName’.
// It is also possible to return all columns of all the
// deleted records by using ‘RETURNING *’.
dbClient
.readWriteTransaction()
.run(
transaction -> {
String sql =
"DELETE FROM Singers WHERE FirstName = 'Alice' RETURNING SingerId, FullName";
// readWriteTransaction.executeQuery(..) API should be used for executing
// DML statements with RETURNING clause.
try (ResultSet resultSet = transaction.executeQuery(Statement.of(sql))) {
while (resultSet.next()) {
System.out.printf("%d %s\n", resultSet.getLong(0), resultSet.getString(1));
}
System.out.printf(
"Deleted row(s) count: %d\n", resultSet.getStats().getRowCountExact());
}
return null;
});
}
}
}Node.js
// Imports the Google Cloud client library.
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
function pgDeleteUsingDmlReturning(instanceId, databaseId) {
// Gets a reference to a Cloud Spanner instance and database.
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
const [rows, stats] = await transaction.run({
sql: 'DELETE FROM Singers WHERE SingerId = 18 RETURNING FullName',
});
const rowCount = Math.floor(stats[stats.rowCount]);
console.log(
`Successfully deleted ${rowCount} record from the Singers table.`
);
rows.forEach(row => {
console.log(row.toJSON().fullname);
});
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});
}
pgDeleteUsingDmlReturning(instanceId, databaseId);PHP
use Google\Cloud\Spanner\SpannerClient;
/**
* Delete data from the given postgresql database using DML returning.
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function pg_delete_dml_returning(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$transaction = $database->transaction();
// Delete records from SINGERS table satisfying a particular condition and
// returns the SingerId and FullName column of the deleted records using
// ‘RETURNING SingerId, FullName’. It is also possible to return all columns
// of all the deleted records by using ‘RETURNING *’.
$result = $transaction->execute(
"DELETE FROM Singers WHERE FirstName = 'Alice' "
. 'RETURNING SingerId, FullName',
);
foreach ($result->rows() as $row) {
printf(
'%d %s.' . PHP_EOL,
$row['singerid'],
$row['fullname']
);
}
printf(
'Deleted row(s) count: %d' . PHP_EOL,
$result->stats()['rowCountExact']
);
$transaction->commit();
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
# Delete records from SINGERS table satisfying a
# particular condition and returns the SingerId
# and FullName column of the deleted records using
# 'RETURNING SingerId, FullName'.
# It is also possible to return all columns of all the
# deleted records by using 'RETURNING *'.
def delete_singers(transaction):
results = transaction.execute_sql(
"DELETE FROM Singers WHERE FirstName = 'David' "
"RETURNING SingerId, FullName"
)
for result in results:
print("SingerId: {}, FullName: {}".format(*result))
print("{} record(s) deleted.".format(results.stats.row_count_exact))
database.run_in_transaction(delete_singers)Ruby
require "google/cloud/spanner"
##
# This is a snippet for showcasing how to use DML return feature with delete
# operation in PostgreSql.
#
# @param project_id [String] The ID of the Google Cloud project.
# @param instance_id [String] The ID of the spanner instance.
# @param database_id [String] The ID of the database.
#
def spanner_postgresql_delete_dml_returning project_id:, instance_id:, database_id:
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
client.transaction do |transaction|
# Delete records from SINGERS table satisfying a particular condition and
# returns the SingerId and FullName column of the deleted records using
# ‘RETURNING SingerId, FullName’.
# It is also possible to return all columns of all the deleted records
# by using ‘RETURNING *’.
results = transaction.execute_query "DELETE FROM singers WHERE firstname = 'Alice' RETURNING SingerId, FullName"
results.rows.each do |row|
puts "Deleted singer with SingerId: #{row[:singerid]}, FullName: #{row[:fullname]}"
end
puts "Deleted row(s) count: #{results.row_count}"
end
end
Membaca data yang ditulis dalam transaksi yang sama
Perubahan yang Anda buat menggunakan pernyataan DML akan terlihat oleh pernyataan berikutnya dalam transaksi yang sama. Hal ini berbeda dengan menggunakan mutasi, saat perubahan tidak terlihat hingga transaksi di-commit.
Spanner memeriksa batasan setelah setiap pernyataan DML. Hal ini berbeda dengan penggunaan mutasi, saat Spanner akan mem-buffer mutasi di klien hingga melakukan commit dan memeriksa batasan pada waktu commit. Mengevaluasi batasan setelah setiap pernyataan memungkinkan Spanner untuk menjamin bahwa data yang ditampilkan oleh pernyataan DML konsisten dengan skema.
Contoh berikut memperbarui baris dalam tabel Singers, lalu mengeksekusi
pernyataan SELECT untuk mencetak nilai baru.
C++
void DmlWriteThenRead(google::cloud::spanner::Client client) {
namespace spanner = ::google::cloud::spanner;
using ::google::cloud::StatusOr;
auto commit_result = client.Commit(
[&client](spanner::Transaction txn) -> StatusOr<spanner::Mutations> {
auto insert = client.ExecuteDml(
txn, spanner::SqlStatement(
"INSERT INTO Singers (SingerId, FirstName, LastName)"
" VALUES (11, 'Timothy', 'Campbell')"));
if (!insert) return std::move(insert).status();
// Read newly inserted record.
spanner::SqlStatement select(
"SELECT FirstName, LastName FROM Singers where SingerId = 11");
using RowType = std::tuple<std::string, std::string>;
auto rows = client.ExecuteQuery(std::move(txn), std::move(select));
// Note: This mutator might be re-run, or its effects discarded, so
// changing non-transactional state (e.g., by producing output) is,
// in general, not something to be imitated.
for (auto const& row : spanner::StreamOf<RowType>(rows)) {
if (!row) return std::move(row).status();
std::cout << "FirstName: " << std::get<0>(*row) << "\t";
std::cout << "LastName: " << std::get<1>(*row) << "\n";
}
return spanner::Mutations{};
});
if (!commit_result) throw std::move(commit_result).status();
std::cout << "Write then read succeeded [spanner_dml_write_then_read]\n";
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;
public class WriteAndReadUsingDmlCoreAsyncSample
{
public async Task<int> WriteAndReadUsingDmlCoreAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
using var createDmlCmd = connection.CreateDmlCommand(@"INSERT Singers (SingerId, FirstName, LastName) VALUES (11, 'Timothy', 'Campbell')");
int rowCount = await createDmlCmd.ExecuteNonQueryAsync();
Console.WriteLine($"{rowCount} row(s) inserted...");
// Read newly inserted record.
using var createSelectCmd = connection.CreateSelectCommand(@"SELECT FirstName, LastName FROM Singers WHERE SingerId = 11");
using var reader = await createSelectCmd.ExecuteReaderAsync();
while (await reader.ReadAsync())
{
Console.WriteLine($"{reader.GetFieldValue<string>("FirstName")} {reader.GetFieldValue<string>("LastName")}");
}
return rowCount;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
"google.golang.org/api/iterator"
)
func writeAndReadUsingDML(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
// Insert Record
stmt := spanner.Statement{
SQL: `INSERT Singers (SingerId, FirstName, LastName)
VALUES (11, 'Timothy', 'Campbell')`,
}
rowCount, err := txn.Update(ctx, stmt)
if err != nil {
return err
}
fmt.Fprintf(w, "%d record(s) inserted.\n", rowCount)
// Read newly inserted record
stmt = spanner.Statement{SQL: `SELECT FirstName, LastName FROM Singers WHERE SingerId = 11`}
iter := txn.Query(ctx, stmt)
defer iter.Stop()
for {
row, err := iter.Next()
if err == iterator.Done || err != nil {
break
}
var firstName, lastName string
if err := row.ColumnByName("FirstName", &firstName); err != nil {
return err
}
if err := row.ColumnByName("LastName", &lastName); err != nil {
return err
}
fmt.Fprintf(w, "Found record name with %s, %s", firstName, lastName)
}
return err
})
return err
}
Java
static void writeAndReadUsingDml(DatabaseClient dbClient) {
dbClient
.readWriteTransaction()
.run(transaction -> {
// Insert record.
String sql =
"INSERT INTO Singers (SingerId, FirstName, LastName) "
+ " VALUES (11, 'Timothy', 'Campbell')";
long rowCount = transaction.executeUpdate(Statement.of(sql));
System.out.printf("%d record inserted.\n", rowCount);
// Read newly inserted record.
sql = "SELECT FirstName, LastName FROM Singers WHERE SingerId = 11";
// We use a try-with-resource block to automatically release resources held by
// ResultSet.
try (ResultSet resultSet = transaction.executeQuery(Statement.of(sql))) {
while (resultSet.next()) {
System.out.printf(
"%s %s\n",
resultSet.getString("FirstName"), resultSet.getString("LastName"));
}
}
return null;
});
}Node.js
// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
database.runTransaction(async (err, transaction) => {
if (err) {
console.error(err);
return;
}
try {
await transaction.runUpdate({
sql: `INSERT Singers (SingerId, FirstName, LastName)
VALUES (11, 'Timothy', 'Campbell')`,
});
const [rows] = await transaction.run({
sql: 'SELECT FirstName, LastName FROM Singers',
});
rows.forEach(row => {
const json = row.toJSON();
console.log(`${json.FirstName} ${json.LastName}`);
});
await transaction.commit();
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}
});PHP
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Transaction;
/**
* Writes then reads data inside a Transaction with a DML statement.
*
* The database and table must already exist and can be created using
* `create_database`.
* Example:
* ```
* insert_data($instanceId, $databaseId);
* ```
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function write_read_with_dml(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$database->runTransaction(function (Transaction $t) {
$rowCount = $t->executeUpdate(
'INSERT Singers (SingerId, FirstName, LastName) '
. " VALUES (11, 'Timothy', 'Campbell')");
printf('Inserted %d row(s).' . PHP_EOL, $rowCount);
$results = $t->execute('SELECT FirstName, LastName FROM Singers WHERE SingerId = 11');
foreach ($results as $row) {
printf('%s %s' . PHP_EOL, $row['FirstName'], $row['LastName']);
}
$t->commit();
});
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def write_then_read(transaction):
# Insert record.
row_ct = transaction.execute_update(
"INSERT INTO Singers (SingerId, FirstName, LastName) "
" VALUES (11, 'Timothy', 'Campbell')"
)
print("{} record(s) inserted.".format(row_ct))
# Read newly inserted record.
results = transaction.execute_sql(
"SELECT FirstName, LastName FROM Singers WHERE SingerId = 11"
)
for result in results:
print("FirstName: {}, LastName: {}".format(*result))
database.run_in_transaction(write_then_read)Ruby
# project_id = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"
require "google/cloud/spanner"
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
row_count = 0
client.transaction do |transaction|
row_count = transaction.execute_update(
"INSERT INTO Singers (SingerId, FirstName, LastName) VALUES (11, 'Timothy', 'Campbell')"
)
puts "#{row_count} record updated."
transaction.execute("SELECT FirstName, LastName FROM Singers WHERE SingerId = 11").rows.each do |row|
puts "#{row[:FirstName]} #{row[:LastName]}"
end
endMendapatkan paket kueri
Anda dapat mengambil paket kueri
menggunakan Konsol Google Cloud, library klien, dan alat
command line gcloud.
Gunakan DML yang Dipartisi
DML Terpartisi dirancang untuk update dan penghapusan massal, terutama pembersihan dan pengisian ulang berkala.
Menjalankan pernyataan dengan Google Cloud CLI
Untuk menjalankan pernyataan DML yang dipartisi, gunakan
perintah gcloud spanner databases execute-sql dengan
opsi --enable-partitioned-dml. Contoh berikut memperbarui baris dalam tabel Albums.
gcloud spanner databases execute-sql example-db \ --instance=test-instance --enable-partitioned-dml \ --sql='UPDATE Albums SET MarketingBudget = 0 WHERE MarketingBudget IS NULL'
Mengubah data menggunakan library klien
Contoh kode berikut memperbarui kolom MarketingBudget pada tabel Albums.
C++
Anda menggunakan fungsi ExecutePartitionedDml() untuk mengeksekusi pernyataan DML yang dipartisi.
void DmlPartitionedUpdate(google::cloud::spanner::Client client) {
namespace spanner = ::google::cloud::spanner;
auto result = client.ExecutePartitionedDml(
spanner::SqlStatement("UPDATE Albums SET MarketingBudget = 100000"
" WHERE SingerId > 1"));
if (!result) throw std::move(result).status();
std::cout << "Updated at least " << result->row_count_lower_bound
<< " row(s) [spanner_dml_partitioned_update]\n";
}C#
Anda menggunakan metode ExecutePartitionedUpdateAsync() untuk mengeksekusi pernyataan DML yang dipartisi.
using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;
public class UpdateUsingPartitionedDmlCoreAsyncSample
{
public async Task<long> UpdateUsingPartitionedDmlCoreAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
using var cmd = connection.CreateDmlCommand("UPDATE Albums SET MarketingBudget = 100000 WHERE SingerId > 1");
long rowCount = await cmd.ExecutePartitionedUpdateAsync();
Console.WriteLine($"{rowCount} row(s) updated...");
return rowCount;
}
}Go
Anda menggunakan metode PartitionedUpdate() untuk mengeksekusi pernyataan DML yang dipartisi.
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
)
func updateUsingPartitionedDML(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
stmt := spanner.Statement{SQL: "UPDATE Albums SET MarketingBudget = 100000 WHERE SingerId > 1"}
rowCount, err := client.PartitionedUpdate(ctx, stmt)
if err != nil {
return err
}
fmt.Fprintf(w, "%d record(s) updated.\n", rowCount)
return nil
}
Java
Anda menggunakan metode executePartitionedUpdate() untuk mengeksekusi pernyataan DML yang dipartisi.
static void updateUsingPartitionedDml(DatabaseClient dbClient) {
String sql = "UPDATE Albums SET MarketingBudget = 100000 WHERE SingerId > 1";
long rowCount = dbClient.executePartitionedUpdate(Statement.of(sql));
System.out.printf("%d records updated.\n", rowCount);
}Node.js
Anda menggunakan metode runPartitionedUpdate() untuk mengeksekusi pernyataan DML yang dipartisi.
// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
try {
const [rowCount] = await database.runPartitionedUpdate({
sql: 'UPDATE Albums SET MarketingBudget = 100000 WHERE SingerId > 1',
});
console.log(`Successfully updated ${rowCount} records.`);
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}PHP
Anda menggunakan metode executePartitionedUpdate() untuk mengeksekusi pernyataan DML yang dipartisi.
use Google\Cloud\Spanner\SpannerClient;
/**
* Updates sample data in the database by partition with a DML statement.
*
* This updates the `MarketingBudget` column which must be created before
* running this sample. You can add the column by running the `add_column`
* sample or by running this DDL statement against your database:
*
* ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
*
* Example:
* ```
* update_data($instanceId, $databaseId);
* ```
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function update_data_with_partitioned_dml(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$rowCount = $database->executePartitionedUpdate(
'UPDATE Albums SET MarketingBudget = 100000 WHERE SingerId > 1'
);
printf('Updated %d row(s).' . PHP_EOL, $rowCount);
}Python
Anda menggunakan metode execute_partitioned_dml() untuk mengeksekusi pernyataan DML yang dipartisi.
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
row_ct = database.execute_partitioned_dml(
"UPDATE Albums SET MarketingBudget = 100000 WHERE SingerId > 1"
)
print("{} records updated.".format(row_ct))Ruby
Anda menggunakan metode execute_partitioned_update() untuk mengeksekusi pernyataan DML yang dipartisi.
# project_id = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"
require "google/cloud/spanner"
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
row_count = client.execute_partition_update(
"UPDATE Albums SET MarketingBudget = 100000 WHERE SingerId > 1"
)
puts "#{row_count} records updated."Contoh kode berikut menghapus baris dari tabel Singers, berdasarkan kolom
SingerId.
C++
void DmlPartitionedDelete(google::cloud::spanner::Client client) {
namespace spanner = ::google::cloud::spanner;
auto result = client.ExecutePartitionedDml(
spanner::SqlStatement("DELETE FROM Singers WHERE SingerId > 10"));
if (!result) throw std::move(result).status();
std::cout << "Deleted at least " << result->row_count_lower_bound
<< " row(s) [spanner_dml_partitioned_delete]\n";
}C#
using Google.Cloud.Spanner.Data;
using System;
using System.Threading.Tasks;
public class DeleteUsingPartitionedDmlCoreAsyncSample
{
public async Task<long> DeleteUsingPartitionedDmlCoreAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
using var cmd = connection.CreateDmlCommand("DELETE FROM Singers WHERE SingerId > 10");
long rowCount = await cmd.ExecutePartitionedUpdateAsync();
Console.WriteLine($"{rowCount} row(s) deleted...");
return rowCount;
}
}Go
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
)
func deleteUsingPartitionedDML(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
stmt := spanner.Statement{SQL: "DELETE FROM Singers WHERE SingerId > 10"}
rowCount, err := client.PartitionedUpdate(ctx, stmt)
if err != nil {
return err
}
fmt.Fprintf(w, "%d record(s) deleted.", rowCount)
return nil
}
Java
static void deleteUsingPartitionedDml(DatabaseClient dbClient) {
String sql = "DELETE FROM Singers WHERE SingerId > 10";
long rowCount = dbClient.executePartitionedUpdate(Statement.of(sql));
System.out.printf("%d records deleted.\n", rowCount);
}Node.js
// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
try {
const [rowCount] = await database.runPartitionedUpdate({
sql: 'DELETE FROM Singers WHERE SingerId > 10',
});
console.log(`Successfully deleted ${rowCount} records.`);
} catch (err) {
console.error('ERROR:', err);
} finally {
// Close the database when finished.
database.close();
}PHP
use Google\Cloud\Spanner\SpannerClient;
/**
* Delete sample data in the database by partition with a DML statement.
*
* This updates the `MarketingBudget` column which must be created before
* running this sample. You can add the column by running the `add_column`
* sample or by running this DDL statement against your database:
*
* ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
*
* Example:
* ```
* update_data($instanceId, $databaseId);
* ```
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function delete_data_with_partitioned_dml(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$rowCount = $database->executePartitionedUpdate(
'DELETE FROM Singers WHERE SingerId > 10'
);
printf('Deleted %d row(s).' . PHP_EOL, $rowCount);
}Python
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
row_ct = database.execute_partitioned_dml("DELETE FROM Singers WHERE SingerId > 10")
print("{} record(s) deleted.".format(row_ct))Ruby
# project_id = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"
require "google/cloud/spanner"
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
row_count = client.execute_partition_update(
"DELETE FROM Singers WHERE SingerId > 10"
)
puts "#{row_count} records deleted."Menggunakan DML batch
Jika Anda perlu menghindari latensi tambahan yang ditimbulkan dari beberapa permintaan serial,
gunakan DML batch untuk mengirim beberapa pernyataan INSERT, UPDATE, atau DELETE dalam
satu transaksi:
C++
Gunakan fungsi ExecuteBatchDml() untuk mengeksekusi daftar pernyataan DML.
void DmlBatchUpdate(google::cloud::spanner::Client client) {
namespace spanner = ::google::cloud::spanner;
auto commit_result =
client.Commit([&client](spanner::Transaction const& txn)
-> google::cloud::StatusOr<spanner::Mutations> {
std::vector<spanner::SqlStatement> statements = {
spanner::SqlStatement("INSERT INTO Albums"
" (SingerId, AlbumId, AlbumTitle,"
" MarketingBudget)"
" VALUES (1, 3, 'Test Album Title', 10000)"),
spanner::SqlStatement("UPDATE Albums"
" SET MarketingBudget = MarketingBudget * 2"
" WHERE SingerId = 1 and AlbumId = 3")};
auto result = client.ExecuteBatchDml(txn, statements);
if (!result) return std::move(result).status();
// Note: This mutator might be re-run, or its effects discarded, so
// changing non-transactional state (e.g., by producing output) is,
// in general, not something to be imitated.
for (std::size_t i = 0; i < result->stats.size(); ++i) {
std::cout << result->stats[i].row_count << " rows affected"
<< " for the statement " << (i + 1) << ".\n";
}
// Batch operations may have partial failures, in which case
// ExecuteBatchDml returns with success, but the application should
// verify that all statements completed successfully
if (!result->status.ok()) return result->status;
return spanner::Mutations{};
});
if (!commit_result) throw std::move(commit_result).status();
std::cout << "Update was successful [spanner_dml_batch_update]\n";
}C#
Gunakan metode connection.CreateBatchDmlCommand() untuk membuat perintah batch, gunakan metode Add untuk menambahkan pernyataan DML, dan jalankan pernyataan dengan metode ExecuteNonQueryAsync().
using Google.Cloud.Spanner.Data;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
public class UpdateUsingBatchDmlCoreAsyncSample
{
public async Task<int> UpdateUsingBatchDmlCoreAsync(string projectId, string instanceId, string databaseId)
{
string connectionString = $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}";
using var connection = new SpannerConnection(connectionString);
await connection.OpenAsync();
SpannerBatchCommand cmd = connection.CreateBatchDmlCommand();
cmd.Add("INSERT INTO Albums (SingerId, AlbumId, AlbumTitle, MarketingBudget) VALUES (1, 3, 'Test Album Title', 10000)");
cmd.Add("UPDATE Albums SET MarketingBudget = MarketingBudget * 2 WHERE SingerId = 1 and AlbumId = 3");
IEnumerable<long> affectedRows = await cmd.ExecuteNonQueryAsync();
Console.WriteLine($"Executed {affectedRows.Count()} " + "SQL statements using Batch DML.");
return affectedRows.Count();
}
}Go
Gunakan metode BatchUpdate() untuk mengeksekusi array objek Statement DML.
import (
"context"
"fmt"
"io"
"cloud.google.com/go/spanner"
)
func updateUsingBatchDML(w io.Writer, db string) error {
ctx := context.Background()
client, err := spanner.NewClient(ctx, db)
if err != nil {
return err
}
defer client.Close()
_, err = client.ReadWriteTransaction(ctx, func(ctx context.Context, txn *spanner.ReadWriteTransaction) error {
stmts := []spanner.Statement{
{SQL: `INSERT INTO Albums
(SingerId, AlbumId, AlbumTitle, MarketingBudget)
VALUES (1, 3, 'Test Album Title', 10000)`},
{SQL: `UPDATE Albums
SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 3`},
}
rowCounts, err := txn.BatchUpdate(ctx, stmts)
if err != nil {
return err
}
fmt.Fprintf(w, "Executed %d SQL statements using Batch DML.\n", len(rowCounts))
return nil
})
return err
}
Java
Gunakan metode transaction.batchUpdate() untuk menjalankan ArrayList
beberapa objek Statement DML.
static void updateUsingBatchDml(DatabaseClient dbClient) {
dbClient
.readWriteTransaction()
.run(transaction -> {
List<Statement> stmts = new ArrayList<Statement>();
String sql =
"INSERT INTO Albums "
+ "(SingerId, AlbumId, AlbumTitle, MarketingBudget) "
+ "VALUES (1, 3, 'Test Album Title', 10000) ";
stmts.add(Statement.of(sql));
sql =
"UPDATE Albums "
+ "SET MarketingBudget = MarketingBudget * 2 "
+ "WHERE SingerId = 1 and AlbumId = 3";
stmts.add(Statement.of(sql));
long[] rowCounts;
try {
rowCounts = transaction.batchUpdate(stmts);
} catch (SpannerBatchUpdateException e) {
rowCounts = e.getUpdateCounts();
}
for (int i = 0; i < rowCounts.length; i++) {
System.out.printf("%d record updated by stmt %d.\n", rowCounts[i], i);
}
return null;
});
}Node.js
Gunakan transaction.batchUpdate() untuk mengeksekusi daftar pernyataan DML.
// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');
/**
* TODO(developer): Uncomment the following lines before running the sample.
*/
// const projectId = 'my-project-id';
// const instanceId = 'my-instance';
// const databaseId = 'my-database';
// Creates a client
const spanner = new Spanner({
projectId: projectId,
});
// Gets a reference to a Cloud Spanner instance and database
const instance = spanner.instance(instanceId);
const database = instance.database(databaseId);
const insert = {
sql: `INSERT INTO Albums (SingerId, AlbumId, AlbumTitle, MarketingBudget)
VALUES (1, 3, "Test Album Title", 10000)`,
};
const update = {
sql: `UPDATE Albums SET MarketingBudget = MarketingBudget * 2
WHERE SingerId = 1 and AlbumId = 3`,
};
const dmlStatements = [insert, update];
try {
await database.runTransactionAsync(async transaction => {
const [rowCounts] = await transaction.batchUpdate(dmlStatements);
await transaction.commit();
console.log(
`Successfully executed ${rowCounts.length} SQL statements using Batch DML.`
);
});
} catch (err) {
console.error('ERROR:', err);
throw err;
} finally {
// Close the database when finished.
database.close();
}PHP
Gunakan executeUpdateBatch() untuk membuat daftar pernyataan DML, lalu gunakan commit() untuk mengeksekusi pernyataan.
use Google\Cloud\Spanner\SpannerClient;
use Google\Cloud\Spanner\Transaction;
/**
* Updates sample data in the database with Batch DML.
*
* This requires the `MarketingBudget` column which must be created before
* running this sample. You can add the column by running the `add_column`
* sample or by running this DDL statement against your database:
*
* ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
*
* Example:
* ```
* update_data_with_batch_dml($instanceId, $databaseId);
* ```
*
* @param string $instanceId The Spanner instance ID.
* @param string $databaseId The Spanner database ID.
*/
function update_data_with_batch_dml(string $instanceId, string $databaseId): void
{
$spanner = new SpannerClient();
$instance = $spanner->instance($instanceId);
$database = $instance->database($databaseId);
$batchDmlResult = $database->runTransaction(function (Transaction $t) {
$result = $t->executeUpdateBatch([
[
'sql' => 'INSERT INTO Albums '
. '(SingerId, AlbumId, AlbumTitle, MarketingBudget) '
. "VALUES (1, 3, 'Test Album Title', 10000)"
],
[
'sql' => 'UPDATE Albums '
. 'SET MarketingBudget = MarketingBudget * 2 '
. 'WHERE SingerId = 1 and AlbumId = 3'
],
]);
$t->commit();
$rowCounts = count($result->rowCounts());
printf('Executed %s SQL statements using Batch DML.' . PHP_EOL,
$rowCounts);
});
}Python
Gunakan transaction.batch_update() untuk menjalankan beberapa string pernyataan DML.
from google.rpc.code_pb2 import OK
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
insert_statement = (
"INSERT INTO Albums "
"(SingerId, AlbumId, AlbumTitle, MarketingBudget) "
"VALUES (1, 3, 'Test Album Title', 10000)"
)
update_statement = (
"UPDATE Albums "
"SET MarketingBudget = MarketingBudget * 2 "
"WHERE SingerId = 1 and AlbumId = 3"
)
def update_albums(transaction):
status, row_cts = transaction.batch_update([insert_statement, update_statement])
if status.code != OK:
# Do handling here.
# Note: the exception will still be raised when
# `commit` is called by `run_in_transaction`.
return
print("Executed {} SQL statements using Batch DML.".format(len(row_cts)))
database.run_in_transaction(update_albums)Ruby
Gunakan transaction.batch_update untuk menjalankan beberapa string pernyataan DML.
# project_id = "Your Google Cloud project ID"
# instance_id = "Your Spanner instance ID"
# database_id = "Your Spanner database ID"
require "google/cloud/spanner"
spanner = Google::Cloud::Spanner.new project: project_id
client = spanner.client instance_id, database_id
row_counts = nil
client.transaction do |transaction|
row_counts = transaction.batch_update do |b|
b.batch_update(
"INSERT INTO Albums " \
"(SingerId, AlbumId, AlbumTitle, MarketingBudget) " \
"VALUES (1, 3, 'Test Album Title', 10000)"
)
b.batch_update(
"UPDATE Albums " \
"SET MarketingBudget = MarketingBudget * 2 " \
"WHERE SingerId = 1 and AlbumId = 3"
)
end
end
statement_count = row_counts.count
puts "Executed #{statement_count} SQL statements using Batch DML."