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Driver Amazon QLDB untuk .NET - Tutorial mulai cepat
Dalam tutorial ini, Anda belajar cara mengatur aplikasi sederhana menggunakan driver Amazon QLDB untuk .NET. Panduan ini mencakup langkah-langkah untuk menginstal driver dan contoh kode pendek dari operasi pembuatan, pembacaan, pembaruan, dan penghapusan (CRUD).
Prasyarat
Sebelum memulai, pastikan Anda melakukan hal berikut:
Langkah 1: Siapkan proyek Anda
Pertama, siapkan proyek .NET Anda.
-
Untuk membuat dan menjalankan aplikasi template, masukkandotnet
perintah berikut pada terminal seperti bash, PowerShell, atau Command Prompt.
$
dotnet new console --output Amazon.QLDB.QuickStartGuide
$
dotnet run --project Amazon.QLDB.QuickStartGuide
Template ini membuat folder bernamaAmazon.QLDB.QuickStartGuide
. Dalam folder itu, itu menciptakan sebuah proyek dengan nama yang sama dan file bernamaProgram.cs
. Program ini berisi kode yang menampilkan outputHello World!
.
-
Gunakan manajer NuGet paket untuk menginstal driver QLDB untuk .NET. Sebaiknya gunakan Visual Studio atau IDE pilihan Anda untuk menambahkan dependensi ke proyek Anda. Nama paket driver adalah Amazon.qldb.driver.
-
Misalnya di Visual Studio, buka NuGet Package Manager Console pada menu Tools. Kemudian, masukkan perintah berikut diPM>
prompt.
PM>
Install-Package Amazon.QLDB.Driver
-
Atau, Anda dapat memasukkan perintah berikut di terminal Anda.
$
cd Amazon.QLDB.QuickStartGuide
$
dotnet add package Amazon.QLDB.Driver
Menginstal driver juga menginstal dependensinya, termasuk library AWS SDK for .NETdan Amazon Ion.
-
Instal pustaka serialisasi driver.
PM>
Install-Package Amazon.QLDB.Driver.Serialization
-
Buka file Program.cs
.
Kemudian, secara bertahap menambahkan contoh kode dalam langkah-langkah berikut untuk mencoba beberapa operasi CRUD dasar. Atau, Anda dapat melewati step-by-step tutorial dan sebagai gantinya menjalankan aplikasi lengkap.
-
Memilih antara API sinkron dan asinkron - Driver menyediakan API sinkron dan asinkron. Untuk aplikasi permintaan tinggi yang menangani beberapa permintaan tanpa memblokir, sebaiknya gunakan API asinkron untuk meningkatkan kinerja. Pengemudi menawarkan API sinkron sebagai kenyamanan tambahan untuk basis kode yang ada yang ditulis secara serempak.
Tutorial ini mencakup contoh kode sinkron dan asinkron. Untuk informasi lebih lanjut tentang API, lihatAsyncQldbDriver antarmuka IQldbDriver dan I dalam dokumentasi API.
-
Memproses data Amazon Ion - Tutorial ini memberikan contoh kode untuk memproses data Amazon Ion menggunakan pemeta objek Ion secara default. QLDB memperkenalkan pemetaan objek Ion dalam versi 1.3.0 dari driver .NET. Jika berlaku, tutorial ini juga menyediakan contoh kode menggunakan pustaka Ion standar sebagai alternatif. Untuk mempelajari selengkapnya, lihat Bekerja dengan Amazon Ion.
Langkah 2: Inisialisasi driver
Inisialisasi instance driver yang terhubung ke buku besar bernamaquick-start
. Tambahkan kode berikut keProgram.cs
file Anda.
- Async
-
using Amazon.QLDB.Driver;
using Amazon.QLDB.Driver.Generic;
using Amazon.QLDB.Driver.Serialization;
namespace Amazon.QLDB.QuickStartGuide
{
class Program
{
public class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public override string ToString()
{
return FirstName + ", " + LastName + ", " + Age.ToString();
}
}
static async Task Main(string[] args)
{
Console.WriteLine("Create the async QLDB driver");
IAsyncQldbDriver driver = AsyncQldbDriver.Builder()
.WithLedger("quick-start")
.WithSerializer(new ObjectSerializer())
.Build();
}
}
}
- Sync
-
using Amazon.QLDB.Driver;
using Amazon.QLDB.Driver.Generic;
using Amazon.QLDB.Driver.Serialization;
namespace Amazon.QLDB.QuickStartGuide
{
class Program
{
public class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public override string ToString()
{
return FirstName + ", " + LastName + ", " + Age.ToString();
}
}
static void Main(string[] args)
{
Console.WriteLine("Create the sync QLDB driver");
IQldbDriver driver = QldbDriver.Builder()
.WithLedger("quick-start")
.WithSerializer(new ObjectSerializer())
.Build();
}
}
}
- Async
-
using System;
using System.Threading.Tasks;
using Amazon.IonDotnet.Tree;
using Amazon.IonDotnet.Tree.Impl;
using Amazon.QLDB.Driver;
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult;
namespace Amazon.QLDB.QuickStartGuide
{
class Program
{
static IValueFactory valueFactory = new ValueFactory();
static async Task Main(string[] args)
{
Console.WriteLine("Create the async QLDB driver");
IAsyncQldbDriver driver = AsyncQldbDriver.Builder()
.WithLedger("quick-start")
.Build();
}
}
}
- Sync
-
using System;
using Amazon.IonDotnet.Tree;
using Amazon.IonDotnet.Tree.Impl;
using Amazon.QLDB.Driver;
namespace Amazon.QLDB.QuickStartGuide
{
class Program
{
static IValueFactory valueFactory = new ValueFactory();
static void Main(string[] args)
{
Console.WriteLine("Create the sync QLDB Driver");
IQldbDriver driver = QldbDriver.Builder()
.WithLedger("quick-start")
.Build();
}
}
}
Langkah 3: Membuat tabel dan indeks
Untuk sisa tutorial ini melalui Langkah 6, Anda perlu menambahkan contoh kode berikut ke contoh kode sebelumnya.
Pada langkah ini, kode berikut menunjukkan bagaimana menjalankanCREATE TABLE
danCREATE INDEX
pernyataan. Ini menciptakan tabel bernamaPerson
dan indeks untukfirstName
bidang pada tabel itu. Indeks diperlukan untuk mengoptimalkan kinerja kueri dan membantu membatasi pengecualian konflik kontrol konkurensi (OCC) yang optimis.
- Async
-
Console.WriteLine("Creating the table and index");
// Creates the table and the index in the same transaction.
// Note: Any code within the lambda can potentially execute multiple times due to retries.
// For more information, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-retry-policy
await driver.Execute(async txn =>
{
await txn.Execute("CREATE TABLE Person");
await txn.Execute("CREATE INDEX ON Person(firstName)");
});
- Sync
-
Console.WriteLine("Creating the tables and index");
// Creates the table and the index in the same transaction.
// Note: Any code within the lambda can potentially execute multiple times due to retries.
// For more information, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-retry-policy
driver.Execute(txn =>
{
txn.Execute("CREATE TABLE Person");
txn.Execute("CREATE INDEX ON Person(firstName)");
});
Langkah 4: Masukkan dokumen
Contoh kode berikut ini menunjukkan cara menjalankanINSERT
pernyataan. QLDB mendukung bahasa kueri PartiQL (kompatibel dengan SQL) dan format data Amazon Ion (superset JSON).
Tambahkan kode berikut yang menyisipkan dokumen ke dalamPerson
tabel.
- Async
-
Console.WriteLine("Inserting a document");
Person myPerson = new Person {
FirstName = "John",
LastName = "Doe",
Age = 32
};
await driver.Execute(async txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("INSERT INTO Person ?", myPerson);
await txn.Execute(myQuery);
});
- Sync
-
Console.WriteLine("Inserting a document");
Person myPerson = new Person {
FirstName = "John",
LastName = "Doe",
Age = 32
};
driver.Execute(txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("INSERT INTO Person ?", myPerson);
txn.Execute(myQuery);
});
- Async
-
Console.WriteLine("Inserting a document");
// This is one way of creating Ion values. We can also use an IonLoader.
// For more details, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-cookbook-dotnet.html#cookbook-dotnet.ion
IIonValue ionPerson = valueFactory.NewEmptyStruct();
ionPerson.SetField("firstName", valueFactory.NewString("John"));
ionPerson.SetField("lastName", valueFactory.NewString("Doe"));
ionPerson.SetField("age", valueFactory.NewInt(32));
await driver.Execute(async txn =>
{
await txn.Execute("INSERT INTO Person ?", ionPerson);
});
- Sync
-
Console.WriteLine("Inserting a document");
// This is one way of creating Ion values, we can also use an IonLoader.
// For more details, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-cookbook-dotnet.html#cookbook-dotnet.ion
IIonValue ionPerson = valueFactory.NewEmptyStruct();
ionPerson.SetField("firstName", valueFactory.NewString("John"));
ionPerson.SetField("lastName", valueFactory.NewString("Doe"));
ionPerson.SetField("age", valueFactory.NewInt(32));
driver.Execute(txn =>
{
txn.Execute("INSERT INTO Person ?", ionPerson);
});
Untuk menyisipkan beberapa dokumen dengan menggunakanSISIPKAN pernyataan tunggal, Anda dapat melewati parameter jenis daftar Ion untuk pernyataan sebagai berikut.
// people is an Ion list
txn.Execute("INSERT INTO Person ?", people);
Anda tidak menyertakan variabel placeholder (?
) dalam kurung sudut ganda (<<...>>
) saat meneruskan daftar Ion. Dalam pernyataan PartiQL manual, kurung sudut ganda menunjukkan koleksi unordered dikenal sebagai tas.
Langkah 5: Cari Dokumen
Contoh kode berikut ini menunjukkan cara menjalankanSELECT
pernyataan.
Tambahkan kode berikut yang meminta dokumen dariPerson
tabel.
- Async
-
Console.WriteLine("Querying the table");
// The result from driver.Execute() is buffered into memory because once the
// transaction is committed, streaming the result is no longer possible.
IAsyncResult<Person> selectResult = await driver.Execute(async txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("SELECT * FROM Person WHERE FirstName = ?", "John");
return await txn.Execute(myQuery);
});
await foreach (Person person in selectResult)
{
Console.WriteLine(person);
// John, Doe, 32
}
- Sync
-
Console.WriteLine("Querying the table");
// The result from driver.Execute() is buffered into memory because once the
// transaction is committed, streaming the result is no longer possible.
IResult<Person> selectResult = driver.Execute(txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("SELECT * FROM Person WHERE FirstName = ?", "John");
return txn.Execute(myQuery);
});
foreach (Person person in selectResult)
{
Console.WriteLine(person);
// John, Doe, 32
}
- Async
-
Console.WriteLine("Querying the table");
IIonValue ionFirstName = valueFactory.NewString("John");
// The result from driver.Execute() is buffered into memory because once the
// transaction is committed, streaming the result is no longer possible.
IAsyncResult selectResult = await driver.Execute(async txn =>
{
return await txn.Execute("SELECT * FROM Person WHERE firstName = ?", ionFirstName);
});
await foreach (IIonValue row in selectResult)
{
Console.WriteLine(row.GetField("firstName").StringValue);
Console.WriteLine(row.GetField("lastName").StringValue);
Console.WriteLine(row.GetField("age").IntValue);
}
- Sync
-
Console.WriteLine("Querying the table");
IIonValue ionFirstName = valueFactory.NewString("John");
// The result from driver.Execute() is buffered into memory because once the
// transaction is committed, streaming the result is no longer possible.
IResult selectResult = driver.Execute(txn =>
{
return txn.Execute("SELECT * FROM Person WHERE firstName = ?", ionFirstName);
});
foreach (IIonValue row in selectResult)
{
Console.WriteLine(row.GetField("firstName").StringValue);
Console.WriteLine(row.GetField("lastName").StringValue);
Console.WriteLine(row.GetField("age").IntValue);
}
Contoh ini menggunakan tanda tanya (?
) sebagai placeholder variabel untuk meneruskan informasi dokumen untuk pernyataan. Bila Anda menggunakan placeholder, Anda harus lulus nilai jenisIonValue
.
Langkah 6: Perbarui Dokumen
Contoh kode berikut ini menunjukkan cara menjalankanUPDATE
pernyataan.
-
Tambahkan kode berikut yang memperbarui dokumen dalamPerson
tabel dengan memperbaruiage
ke 42.
- Async
-
Console.WriteLine("Updating the document");
await driver.Execute(async txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("UPDATE Person SET Age = ? WHERE FirstName = ?", 42, "John");
await txn.Execute(myQuery);
});
- Sync
-
Console.WriteLine("Updating the document");
driver.Execute(txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("UPDATE Person SET Age = ? WHERE FirstName = ?", 42, "John");
txn.Execute(myQuery);
});
-
Kueri dokumen lagi untuk melihat nilai yang diperbarui.
- Async
-
Console.WriteLine("Querying the table for the updated document");
IAsyncResult<Person> updateResult = await driver.Execute(async txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("SELECT * FROM Person WHERE FirstName = ?", "John");
return await txn.Execute(myQuery);
});
await foreach (Person person in updateResult)
{
Console.WriteLine(person);
// John, Doe, 42
}
- Sync
-
Console.WriteLine("Querying the table for the updated document");
IResult<Person> updateResult = driver.Execute(txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("SELECT * FROM Person WHERE FirstName = ?", "John");
return txn.Execute(myQuery);
});
foreach (Person person in updateResult)
{
Console.WriteLine(person);
// John, Doe, 42
}
-
Untuk menjalankan aplikasi, masukkan perintah berikut dari direktori induk direktoriAmazon.QLDB.QuickStartGuide
proyek Anda.
$
dotnet run --project Amazon.QLDB.QuickStartGuide
-
Tambahkan kode berikut yang memperbarui dokumen dalamPerson
tabel dengan memperbaruiage
ke 42.
- Async
-
Console.WriteLine("Updating the document");
IIonValue ionIntAge = valueFactory.NewInt(42);
IIonValue ionFirstName2 = valueFactory.NewString("John");
await driver.Execute(async txn =>
{
await txn.Execute("UPDATE Person SET age = ? WHERE firstName = ?", ionIntAge, ionFirstName2);
});
- Sync
-
Console.WriteLine("Updating a document");
IIonValue ionIntAge = valueFactory.NewInt(42);
IIonValue ionFirstName2 = valueFactory.NewString("John");
driver.Execute(txn =>
{
txn.Execute("UPDATE Person SET age = ? WHERE firstName = ?", ionIntAge, ionFirstName2);
});
-
Kueri dokumen lagi untuk melihat nilai yang diperbarui.
- Async
-
Console.WriteLine("Querying the table for the updated document");
IIonValue ionFirstName3 = valueFactory.NewString("John");
IAsyncResult updateResult = await driver.Execute(async txn =>
{
return await txn.Execute("SELECT * FROM Person WHERE firstName = ?", ionFirstName3 );
});
await foreach (IIonValue row in updateResult)
{
Console.WriteLine(row.GetField("firstName").StringValue);
Console.WriteLine(row.GetField("lastName").StringValue);
Console.WriteLine(row.GetField("age").IntValue);
}
- Sync
-
Console.WriteLine("Querying the table for the updated document");
IIonValue ionFirstName3 = valueFactory.NewString("John");
IResult updateResult = driver.Execute(txn =>
{
return txn.Execute("SELECT * FROM Person WHERE firstName = ?", ionFirstName3);
});
foreach (IIonValue row in updateResult)
{
Console.WriteLine(row.GetField("firstName").StringValue);
Console.WriteLine(row.GetField("lastName").StringValue);
Console.WriteLine(row.GetField("age").IntValue);
}
-
Untuk menjalankan aplikasi, masukkan perintah berikut dari direktori induk direktoriAmazon.QLDB.QuickStartGuide
proyek Anda.
$
dotnet run --project Amazon.QLDB.QuickStartGuide
Menjalankan aplikasi lengkap
Contoh kode berikut adalah versi lengkap dariProgram.cs
aplikasi. Alih-alih melakukan langkah-langkah sebelumnya secara individual, Anda juga dapat menyalin dan menjalankan contoh kode ini dari awal hingga akhir. Aplikasi ini menunjukkan beberapa operasi CRUD dasar pada buku besar bernamaquick-start
.
Sebelum Anda menjalankan kode ini, pastikan bahwa Anda belum memiliki tabel aktif bernamaPerson
dalamquick-start
buku besar.
- Async
-
using Amazon.QLDB.Driver;
using Amazon.QLDB.Driver.Generic;
using Amazon.QLDB.Driver.Serialization;
namespace Amazon.QLDB.QuickStartGuide
{
class Program
{
public class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public override string ToString()
{
return FirstName + ", " + LastName + ", " + Age.ToString();
}
}
static async Task Main(string[] args)
{
Console.WriteLine("Create the async QLDB driver");
IAsyncQldbDriver driver = AsyncQldbDriver.Builder()
.WithLedger("quick-start")
.WithSerializer(new ObjectSerializer())
.Build();
Console.WriteLine("Creating the table and index");
// Creates the table and the index in the same transaction.
// Note: Any code within the lambda can potentially execute multiple times due to retries.
// For more information, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-retry-policy
await driver.Execute(async txn =>
{
await txn.Execute("CREATE TABLE Person");
await txn.Execute("CREATE INDEX ON Person(firstName)");
});
Console.WriteLine("Inserting a document");
Person myPerson = new Person {
FirstName = "John",
LastName = "Doe",
Age = 32
};
await driver.Execute(async txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("INSERT INTO Person ?", myPerson);
await txn.Execute(myQuery);
});
Console.WriteLine("Querying the table");
// The result from driver.Execute() is buffered into memory because once the
// transaction is committed, streaming the result is no longer possible.
IAsyncResult<Person> selectResult = await driver.Execute(async txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("SELECT * FROM Person WHERE FirstName = ?", "John");
return await txn.Execute(myQuery);
});
await foreach (Person person in selectResult)
{
Console.WriteLine(person);
// John, Doe, 32
}
Console.WriteLine("Updating the document");
await driver.Execute(async txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("UPDATE Person SET Age = ? WHERE FirstName = ?", 42, "John");
await txn.Execute(myQuery);
});
Console.WriteLine("Querying the table for the updated document");
IAsyncResult<Person> updateResult = await driver.Execute(async txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("SELECT * FROM Person WHERE FirstName = ?", "John");
return await txn.Execute(myQuery);
});
await foreach (Person person in updateResult)
{
Console.WriteLine(person);
// John, Doe, 42
}
}
}
}
- Sync
-
using Amazon.QLDB.Driver;
using Amazon.QLDB.Driver.Generic;
using Amazon.QLDB.Driver.Serialization;
namespace Amazon.QLDB.QuickStartGuide
{
class Program
{
public class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public override string ToString()
{
return FirstName + ", " + LastName + ", " + Age.ToString();
}
}
static void Main(string[] args)
{
Console.WriteLine("Create the sync QLDB driver");
IQldbDriver driver = QldbDriver.Builder()
.WithLedger("quick-start")
.WithSerializer(new ObjectSerializer())
.Build();
Console.WriteLine("Creating the table and index");
// Creates the table and the index in the same transaction.
// Note: Any code within the lambda can potentially execute multiple times due to retries.
// For more information, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-retry-policy
driver.Execute(txn =>
{
txn.Execute("CREATE TABLE Person");
txn.Execute("CREATE INDEX ON Person(firstName)");
});
Console.WriteLine("Inserting a document");
Person myPerson = new Person {
FirstName = "John",
LastName = "Doe",
Age = 32
};
driver.Execute(txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("INSERT INTO Person ?", myPerson);
txn.Execute(myQuery);
});
Console.WriteLine("Querying the table");
// The result from driver.Execute() is buffered into memory because once the
// transaction is committed, streaming the result is no longer possible.
IResult<Person> selectResult = driver.Execute(txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("SELECT * FROM Person WHERE FirstName = ?", "John");
return txn.Execute(myQuery);
});
foreach (Person person in selectResult)
{
Console.WriteLine(person);
// John, Doe, 32
}
Console.WriteLine("Updating the document");
driver.Execute(txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("UPDATE Person SET Age = ? WHERE FirstName = ?", 42, "John");
txn.Execute(myQuery);
});
Console.WriteLine("Querying the table for the updated document");
IResult<Person> updateResult = driver.Execute(txn =>
{
IQuery<Person> myQuery = txn.Query<Person>("SELECT * FROM Person WHERE FirstName = ?", "John");
return txn.Execute(myQuery);
});
foreach (Person person in updateResult)
{
Console.WriteLine(person);
// John, Doe, 42
}
}
}
}
- Async
-
using System;
using System.Threading.Tasks;
using Amazon.IonDotnet.Tree;
using Amazon.IonDotnet.Tree.Impl;
using Amazon.QLDB.Driver;
using IAsyncResult = Amazon.QLDB.Driver.IAsyncResult;
namespace Amazon.QLDB.QuickStartGuide
{
class Program
{
static IValueFactory valueFactory = new ValueFactory();
static async Task Main(string[] args)
{
Console.WriteLine("Create the async QLDB driver");
IAsyncQldbDriver driver = AsyncQldbDriver.Builder()
.WithLedger("quick-start")
.Build();
Console.WriteLine("Creating the table and index");
// Creates the table and the index in the same transaction.
// Note: Any code within the lambda can potentially execute multiple times due to retries.
// For more information, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-retry-policy
await driver.Execute(async txn =>
{
await txn.Execute("CREATE TABLE Person");
await txn.Execute("CREATE INDEX ON Person(firstName)");
});
Console.WriteLine("Inserting a document");
// This is one way of creating Ion values. We can also use an IonLoader.
// For more details, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-cookbook-dotnet.html#cookbook-dotnet.ion
IIonValue ionPerson = valueFactory.NewEmptyStruct();
ionPerson.SetField("firstName", valueFactory.NewString("John"));
ionPerson.SetField("lastName", valueFactory.NewString("Doe"));
ionPerson.SetField("age", valueFactory.NewInt(32));
await driver.Execute(async txn =>
{
await txn.Execute("INSERT INTO Person ?", ionPerson);
});
Console.WriteLine("Querying the table");
IIonValue ionFirstName = valueFactory.NewString("John");
// The result from driver.Execute() is buffered into memory because once the
// transaction is committed, streaming the result is no longer possible.
IAsyncResult selectResult = await driver.Execute(async txn =>
{
return await txn.Execute("SELECT * FROM Person WHERE firstName = ?", ionFirstName);
});
await foreach (IIonValue row in selectResult)
{
Console.WriteLine(row.GetField("firstName").StringValue);
Console.WriteLine(row.GetField("lastName").StringValue);
Console.WriteLine(row.GetField("age").IntValue);
}
Console.WriteLine("Updating the document");
IIonValue ionIntAge = valueFactory.NewInt(42);
IIonValue ionFirstName2 = valueFactory.NewString("John");
await driver.Execute(async txn =>
{
await txn.Execute("UPDATE Person SET age = ? WHERE firstName = ?", ionIntAge, ionFirstName2);
});
Console.WriteLine("Querying the table for the updated document");
IIonValue ionFirstName3 = valueFactory.NewString("John");
IAsyncResult updateResult = await driver.Execute(async txn =>
{
return await txn.Execute("SELECT * FROM Person WHERE firstName = ?", ionFirstName3);
});
await foreach (IIonValue row in updateResult)
{
Console.WriteLine(row.GetField("firstName").StringValue);
Console.WriteLine(row.GetField("lastName").StringValue);
Console.WriteLine(row.GetField("age").IntValue);
}
}
}
}
- Sync
-
using System;
using Amazon.IonDotnet.Tree;
using Amazon.IonDotnet.Tree.Impl;
using Amazon.QLDB.Driver;
namespace Amazon.QLDB.QuickStartGuide
{
class Program
{
static IValueFactory valueFactory = new ValueFactory();
static void Main(string[] args)
{
Console.WriteLine("Create the sync QLDB Driver");
IQldbDriver driver = QldbDriver.Builder()
.WithLedger("quick-start")
.Build();
Console.WriteLine("Creating the tables and index");
// Creates the table and the index in the same transaction.
// Note: Any code within the lambda can potentially execute multiple times due to retries.
// For more information, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-retry-policy
driver.Execute(txn =>
{
txn.Execute("CREATE TABLE Person");
txn.Execute("CREATE INDEX ON Person(firstName)");
});
Console.WriteLine("Inserting a document");
// This is one way of creating Ion values. We can also use an IonLoader.
// For more details, see: https://docs.aws.amazon.com/qldb/latest/developerguide/driver-cookbook-dotnet.html#cookbook-dotnet.ion
IIonValue ionPerson = valueFactory.NewEmptyStruct();
ionPerson.SetField("firstName", valueFactory.NewString("John"));
ionPerson.SetField("lastName", valueFactory.NewString("Doe"));
ionPerson.SetField("age", valueFactory.NewInt(32));
driver.Execute(txn =>
{
txn.Execute("INSERT INTO Person ?", ionPerson);
});
Console.WriteLine("Querying the table");
IIonValue ionFirstName = valueFactory.NewString("John");
// The result from driver.Execute() is buffered into memory because once the
// transaction is committed, streaming the result is no longer possible.
IResult selectResult = driver.Execute(txn =>
{
return txn.Execute("SELECT * FROM Person WHERE firstName = ?", ionFirstName);
});
foreach (IIonValue row in selectResult)
{
Console.WriteLine(row.GetField("firstName").StringValue);
Console.WriteLine(row.GetField("lastName").StringValue);
Console.WriteLine(row.GetField("age").IntValue);
}
Console.WriteLine("Updating a document");
IIonValue ionIntAge = valueFactory.NewInt(42);
IIonValue ionFirstName2 = valueFactory.NewString("John");
driver.Execute(txn =>
{
txn.Execute("UPDATE Person SET age = ? WHERE firstName = ?", ionIntAge, ionFirstName2);
});
Console.WriteLine("Querying the table for the updated document");
IIonValue ionFirstName3 = valueFactory.NewString("John");
IResult updateResult = driver.Execute(txn =>
{
return txn.Execute("SELECT * FROM Person WHERE firstName = ?", ionFirstName3);
});
foreach (IIonValue row in updateResult)
{
Console.WriteLine(row.GetField("firstName").StringValue);
Console.WriteLine(row.GetField("lastName").StringValue);
Console.WriteLine(row.GetField("age").IntValue);
}
}
}
}
Untuk menjalankan aplikasi lengkap, masukkan perintah berikut dari direktori induk direktoriAmazon.QLDB.QuickStartGuide
proyek Anda.
$
dotnet run --project Amazon.QLDB.QuickStartGuide