Delete many records in one call

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.DeleteMultiple.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_DeleteManyRecords().RunAsync(dbContext);

The sample, as it is in the repository.

using ARX.SDK.DynamoDb.Services;
using ARX.SDK.Services;

using static ArxSamples.DynamoDb.SampleOutput;

namespace ArxSamples.DynamoDb.Operations.DeleteMultiple.Basics;

/// <summary>
/// Many items in one call: three SKUs, one of them unknown. The two found go, in one transaction, and the call returns
/// how many.
/// </summary>
/// <remarks>
/// The deletes are sent conditioned on each item, without a read first, as one <c>TransactWriteItems</c> of at most 100
/// items (more is ARX8001 unless <c>AllowPartial</c>). An id no item has isn't an error; it isn't counted. Delete's
/// "How to find the items" sample deletes many by columns a key or an index gives.
/// </remarks>
public sealed class Basic1_DeleteManyRecords : ISample
{
    public string Name => "delete-multiple-basics-1-delete-many-records";

    public string Title => "Delete many records in one call";

    public async Task RunAsync(SampleContext dbContext)
    {
        var products = new[] { "SKU-D302", "SKU-D303", "SKU-D304" }.Select(sku =>
        {
            var product = new ArxEntity("product");
            product["sku"] = sku;
            product["name"] = $"Clearance item {sku}";
            return product;
        }).ToList();
        await dbContext.Service.CreateMultipleAsync(products);

        await Scenario1_SeveralIdsAtOnceAsync(dbContext.Service);
    }

    /// <summary>1. Three SKUs, one of them unknown: the two found go, in one transaction.</summary>
    private static async Task Scenario1_SeveralIdsAtOnceAsync(ArxDynamoDbService service)
    {
        Step("1. Several ids at once");

        int deleted = await service.DeleteMultipleAsync("product", new[] { "SKU-D302", "SKU-D303", "SKU-D399" });

        Show($"{deleted} items deleted");

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * SELECT "sku" FROM "product" WHERE "sku" IN ['SKU-D302', 'SKU-D303', 'SKU-D304']
         * -- Expect: 1 item, SKU-D304.
         * ===========================================================
         */
    }
}

  > 1. Several ids at once
      2 items deleted