Create one record, in either design

Runs the sample. Generated for this page; it reads the connection string from the environment and first remakes the sample database from sample-schema.json.

using ArxSamples.DynamoDb;
using ArxSamples.DynamoDb.Operations.Create.Basics;

// The connection string comes from the environment, never from the code (see "Configure the connection").
var connectionString = Environment.GetEnvironmentVariable("ARX_SAMPLES_DYNAMODB")
    ?? throw new InvalidOperationException("Set the ARX_SAMPLES_DYNAMODB environment variable to your Amazon DynamoDB connection string.");

var dbContext = new SampleContext(connectionString);

// Every run starts from the sample data: this deletes and makes again what sample-schema.json lists
// (save the file in the project folder, see Get started).
await dbContext.Direct.ResetAsync();

await new Basic1_CreateOneRecord().RunAsync(dbContext);

The sample, as it is in the repository.

using Amazon.DynamoDBv2;
using ARX.SDK.DynamoDb.Model;
using ARX.SDK.DynamoDb.Services;
using ARX.SDK.Services;

using static ArxSamples.DynamoDb.SampleOutput;

namespace ArxSamples.DynamoDb.Operations.Create.Basics;

/// <summary>
/// The smallest create, in the two designs DynamoDB tables are made in: an entity with a table of its own, then a
/// customer and an order sharing one table through key templates.
/// </summary>
/// <remarks>
/// The model says where each entity goes; the code that creates it is the same in both designs. DynamoDB generates no
/// ids: the id is one of the values you give. A create never overwrites: an item with the same key is ARX3001.
/// </remarks>
public sealed class Basic1_CreateOneRecord : ISample
{
    public string Name => "create-basics-1-create-one-record";

    public string Title => "Create one record, in either design";

    public async Task RunAsync(SampleContext dbContext)
    {
        await Scenario1_ATableOfItsOwnAsync(dbContext.Client);

        await Scenario2_OneTableForCustomersAndOrdersAsync(dbContext);
    }

    /// <summary>1. A product in its own table, keyed by its SKU.</summary>
    private static async Task Scenario1_ATableOfItsOwnAsync(IAmazonDynamoDB client)
    {
        Step("1. A table of its own");

        var model = ArxDynamoModel.Create()
            .Table("product", partitionKey: "sku")
            .Build();

        var service = new ArxDynamoDbService(client, model);

        var product = new ArxEntity("product");
        product["sku"] = "SKU-D101";
        product["name"] = "Trail running shoe";
        product["price"] = 129.90m;

        await service.CreateAsync(product);

        Show("created product SKU-D101");

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * SELECT * FROM "product" WHERE "sku" = 'SKU-D101'
         * -- Expect: 1 item, name "Trail running shoe", price 129.9.
         * ===========================================================
         */
    }

    /// <summary>2. A customer and its first order in one table: ARX writes PK, SK and entity_type from the model's templates.</summary>
    private static async Task Scenario2_OneTableForCustomersAndOrdersAsync(SampleContext dbContext)
    {
        Step("2. One table for customers and orders");

        var service = dbContext.Service;

        var customer = new ArxEntity("customer");
        customer["customer_id"] = "C-D101";
        customer["name"] = "Northwind Traders";
        ArxRecordId id = await service.CreateAsync(customer);

        var order = new ArxEntity("sales_order");
        order["customer_id"] = "C-D101";
        order["order_number"] = "SO-D101";
        order["status"] = "OPEN";
        order["ordered_on"] = "2026-11-09";
        order["total"] = 250m;
        await service.CreateAsync(order);

        Show($"created customer {id.AsString()} and order SO-D101");

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * SELECT * FROM "crm" WHERE "PK" = 'CUSTOMER#C-D101'
         * -- Expect: 2 items: SK "ORDER#SO-D101" (entity_type sales_order, GSI1PK "STATUS#OPEN") and SK "PROFILE" (entity_type customer).
         * ===========================================================
         */
    }
}

  > 1. A table of its own
      created product SKU-D101
  > 2. One table for customers and orders
      created customer C-D101 and order SO-D101