Update 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.MongoDb;
using ArxSamples.MongoDb.Operations.UpdateMultiple.Basics;

// The connection string comes from the environment, never from the code (see "Configure the connection").
var connectionString = Environment.GetEnvironmentVariable("ARX_SAMPLES_MONGODB")
    ?? throw new InvalidOperationException("Set the ARX_SAMPLES_MONGODB environment variable to your MongoDB 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_UpdateManyRecords().RunAsync(dbContext);

The sample, as it is in the repository.

using ARX.SDK;
using ARX.SDK.MongoDb.Services;
using ARX.SDK.Services;

using static ArxSamples.MongoDb.SampleOutput;

namespace ArxSamples.MongoDb.Operations.UpdateMultiple.Basics;

/// <summary>
/// Many documents in one call, all or nothing, in two scenarios: a different value for each document, and a list with
/// one id no document has, where none of them changes.
/// </summary>
/// <remarks>
/// UpdateMultiple runs in a transaction, which MongoDB offers on a replica set (one node is enough) or a sharded
/// cluster; on a standalone server it is refused rather than half done. Each entity writes only the fields it sets.
/// </remarks>
public sealed class Basic1_UpdateManyRecords : ISample
{
    public string Name => "update-multiple-basics-1-update-many-records";

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

    public async Task RunAsync(SampleContext dbContext)
    {
        var accounts = new List<ArxEntity>();

        foreach (var number in new[] { "ACC-M921", "ACC-M922", "ACC-M923" })
        {
            var account = new ArxEntity("account");
            account["name"] = "Many updates " + number;
            account["account_number"] = number;
            account["employee_count"] = 10;
            accounts.Add(account);
        }

        var ids = await dbContext.Service.CreateMultipleAsync(accounts);

        await Scenario1_AValuePerDocumentAsync(dbContext.Service, ids);

        await Scenario2_AllOrNothingAsync(dbContext.Service, ids[0]);
    }

    /// <summary>1. One entity per document, each with its own value: the call returns how many changed.</summary>
    private static async Task Scenario1_AValuePerDocumentAsync(ArxMongoDbService service, IReadOnlyList<ArxRecordId> ids)
    {
        Step("1. A value per document");

        var changes = new List<ArxEntity>();

        for (var i = 0; i < ids.Count; i++)
        {
            var change = new ArxEntity("account") { RecordId = ids[i] };
            change["employee_count"] = 100 + i;
            changes.Add(change);
        }

        int changed = await service.UpdateMultipleAsync(changes);

        Show($"{changed} documents changed in one call");

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * db.account.find({ account_number: { $in: ["ACC-M921", "ACC-M922", "ACC-M923"] } }, { account_number: 1, employee_count: 1 }).sort({ account_number: 1 })
         * -- Expect: 3 documents, employee_count 100, 101, 102.
         * ===========================================================
         */
    }

    /// <summary>2. The second id belongs to no document: RecordNotFound, and the first document keeps its value too.</summary>
    private static async Task Scenario2_AllOrNothingAsync(ArxMongoDbService service, ArxRecordId existing)
    {
        Step("2. All or nothing");

        var first = new ArxEntity("account") { RecordId = existing };
        first["employee_count"] = 999;

        var missing = new ArxEntity("account");
        missing["account_id"] = "65a000000000000000000000";
        missing["employee_count"] = 999;

        try
        {
            await service.UpdateMultipleAsync(new[] { first, missing });
        }
        catch (ArxException exception) when (exception.Code == ArxErrorCode.RecordNotFound)
        {
            ShowError(exception);
        }

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * db.account.find({ account_number: "ACC-M921" }, { employee_count: 1 })
         * -- Expect: employee_count 100 (not 999).
         * ===========================================================
         */
    }
}

  > 1. A value per document
      3 documents changed in one call
  > 2. All or nothing
      caught ArxException: ARX2002 RecordNotFound: UpdateMultiple of 'account': 1 of 2 entities matched no document. Nothing was changed.