Update or delete every document a filter matches

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 Basic2_ByAFilter().RunAsync(dbContext);

The sample, as it is in the repository.

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

using static ArxSamples.MongoDb.SampleOutput;

namespace ArxSamples.MongoDb.Operations.UpdateMultiple.Basics;

/// <summary>
/// Every document a filter matches, changed or deleted in one call: one updateMany (or deleteMany) with the filter as a
/// query document, in a transaction, so a document refused half-way leaves every document as it was.
/// </summary>
/// <remarks>
/// <para>The filter takes the operators of a query on the collection's own fields; values are never read as query operators.</para>
/// <para>The entity carries only the values to set: an id or _id is refused (ARX1001), and so is an empty filter unless new ArxFilterWriteOptions { AllRows = true } is passed.</para>
/// <para>Needs ARX.SDK 0.1.0-preview.5 or later, and a replica set (one node is enough).</para>
/// </remarks>
public sealed class Basic2_ByAFilter : ISample
{
    public string Name => "update-multiple-basics-2-by-a-filter";

    public string Title => "Update or delete every document a filter matches";

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

        for (var i = 1; i <= 5; i++)
        {
            var account = new ArxEntity("account");
            account["name"] = $"Filter update {i}";
            account["account_number"] = $"ACC-MF0{i}";
            account["employee_count"] = i * 5;
            account["status"] = "ACTIVE";
            accounts.Add(account);
        }

        await dbContext.Service.CreateMultipleAsync(accounts);

        await Scenario1_UpdateByAFilterAsync(dbContext.Service);

        await Scenario2_DeleteByAFilterAsync(dbContext.Service);
    }

    /// <summary>1. Small accounts put on hold with one updateMany.</summary>
    private static async Task Scenario1_UpdateByAFilterAsync(ArxMongoDbService service)
    {
        Step("1. Update by a filter");

        var change = new ArxEntity("account");
        change["status"] = "ON_HOLD";

        var filter = new ArxFilterExpression();
        filter.AddCondition("account_number", ArxConditionOperator.BeginsWith, "ACC-MF0");
        filter.AddCondition("employee_count", ArxConditionOperator.LessThan, 15);

        int changed = await service.UpdateMultipleAsync(change, filter);

        Show($"{changed} accounts put on hold");

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * db.account.find({ account_number: /^ACC-MF0/ }, { account_number: 1, employee_count: 1, status: 1 }).sort({ account_number: 1 })
         * -- Expect: 5 documents; ACC-MF01 and ACC-MF02 (5 and 10 employees) ON_HOLD, the other three ACTIVE.
         * ===========================================================
         */
    }

    /// <summary>2. The accounts on hold deleted with one deleteMany; the call returns how many went.</summary>
    private static async Task Scenario2_DeleteByAFilterAsync(ArxMongoDbService service)
    {
        Step("2. Delete by a filter");

        var filter = new ArxFilterExpression();
        filter.AddCondition("account_number", ArxConditionOperator.BeginsWith, "ACC-MF0");
        filter.AddCondition("status", ArxConditionOperator.Equal, "ON_HOLD");

        int deleted = await service.DeleteMultipleAsync("account", filter);

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

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * db.account.find({ account_number: /^ACC-MF0/ }, { account_number: 1, status: 1 }).sort({ account_number: 1 })
         * -- Expect: 3 documents, ACC-MF03 to ACC-MF05, all ACTIVE.
         * ===========================================================
         */
    }
}

  > 1. Update by a filter
      2 accounts put on hold
  > 2. Delete by a filter
      2 accounts deleted