SQL Server · Delete

Soft delete: close and restore an account

A soft delete keeps the row and marks it closed: it's an update of a status column, not a delete. Two scenarios: close an account; restore it.

Set up for this page

The scenarios build on the sample application: SampleContext.cs (the dbContext every sample is given); SampleOutput.cs (Step and Show, which print); SampleContext.Application.cs (dbContext.Service, the application's ARX service); SampleCatalog.cs (the tables' ids, keys, lookups and display names).

Before scenario 1 the sample runs this, so the service and the rows the scenarios use are there:

Set up
foreach (var number in new[] { "ACC-D601", "ACC-D602" })
{
    var account = new ArxEntity("account");
    account["name"] = "Soft deleted customer " + number;
    account["account_number"] = number;
    await service.CreateAsync(account);
}

1 Close the account instead of deleting it

"Delete" in the app closes the account: an update of its status, by the account number.

Already in scope: service (ArxMsSqlDbService)

C#
await service.UpdateAsync(Status("ACC-D601", "CLOSED"), new ArxUpdateOptions { Match = ArxMatch.Key("account_number") });
Console.WriteLine("ACC-D601 closed; its history stays");
Used above

Defined once in this sample.

private static ArxEntity Status(string number, string status)
{
    var change = new ArxEntity("account");
    change["account_number"] = number;
    change["status"] = new ArxSelectionSetValue("AccountStatus", status);
    return change;
}

Check it in the database

SQL

Run it in any SQL tool connected to the database, after the code has run.

SELECT account_number, status
FROM account
WHERE account_number = 'ACC-D601';

Expect: 1 row, CLOSED.

2 Restore it

Undo is another update.

Already in scope: service (ArxMsSqlDbService)

C#
var byNumber = new ArxUpdateOptions { Match = ArxMatch.Key("account_number") };
await service.UpdateAsync(Status("ACC-D602", "CLOSED"), byNumber);
await service.UpdateAsync(Status("ACC-D602", "ACTIVE"), byNumber);
Console.WriteLine("ACC-D602 closed, then active again");
Used above

Defined once in this sample.

private static ArxEntity Status(string number, string status)
{
    var change = new ArxEntity("account");
    change["account_number"] = number;
    change["status"] = new ArxSelectionSetValue("AccountStatus", status);
    return change;
}

Check it in the database

SQL

Run it in any SQL tool connected to the database, after the code has run.

SELECT account_number, status
FROM account
WHERE account_number = 'ACC-D602';

Expect: 1 row, ACTIVE.

Run the complete sample

The code above comes from one program, built in a fresh project and run against the database. To run it yourself, here is every file and step.

The program, its files and how to run it

Run it locally

  1. .NET SDK: .NET SDK 10.0.100 or later 10.0.x (target net10.0).
  2. Create the project:
    Terminal
    dotnet new console -n ArxSample -f net10.0
    cd ArxSample
  3. Install the packages:
    Terminal
    dotnet add package ARX.SDK.SQL --version 1.0.0-rc.1
  4. Database: a SQL Server 2022 (tested with 16.0.4225.2) database with the sample schema.
  5. Configuration: set ARX_SAMPLES_SQLSERVER to its connection string. Nothing is hard-coded.
  6. Source code: add the files of the sample application this sample uses (SampleContext.cs, SampleOutput.cs, SampleContext.Application.cs, SampleCatalog.cs), then replace Program.cs and add the other file below, with the file names shown.
  7. Run it:
    Terminal
    dotnet run
  8. Expected output: below.

The files

Program.cs

Runs the sample. Generated for this page; it reads the connection string from the environment.

using ArxSamples.MSSQL;
using ArxSamples.MSSQL.Operations.Delete.RealCases;

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

await new RealCase4_SoftDelete().RunAsync(new SampleContext(connectionString));
RealCase4_SoftDelete.cs

The sample, as it is in the repository.

using ARX.SDK.Services;
using static ArxSamples.MSSQL.SampleOutput;

namespace ArxSamples.MSSQL.Operations.Delete.RealCases;

/// <summary>
/// A soft delete keeps the row and marks it closed: it's an update of a status column, not a delete. Two
/// scenarios: close an account; restore it.
/// </summary>
public sealed class RealCase4_SoftDelete : ISample
{
    public string Name => "delete-real-4-soft-delete";

    public string Title => "Soft delete: close and restore an account";

    public async Task RunAsync(SampleContext dbContext)
    {
        // ACC-D601 is closed and stays closed; ACC-D602 is closed, then restored.
        foreach (var number in new[] { "ACC-D601", "ACC-D602" })
        {
            var account = new ArxEntity("account");
            account["name"] = "Soft deleted customer " + number;
            account["account_number"] = number;
            await dbContext.Service.CreateAsync(account);
        }

        await Scenario1_CloseTheAccountAsync(dbContext);

        await Scenario2_RestoreItAsync(dbContext);
    }

    private static ArxEntity Status(string number, string status)
    {
        var change = new ArxEntity("account");
        change["account_number"] = number;
        change["status"] = new ArxSelectionSetValue("AccountStatus", status);
        return change;
    }

    /// <summary>1. "Delete" in the app closes the account: an update of its status, by the account number.</summary>
    private static async Task Scenario1_CloseTheAccountAsync(SampleContext dbContext)
    {
        Step("1. Close the account instead of deleting it");

        await dbContext.Service.UpdateAsync(Status("ACC-D601", "CLOSED"), new ArxUpdateOptions { Match = ArxMatch.Key("account_number") });
        Show("ACC-D601 closed; its history stays");

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * SELECT account_number, status
         * FROM account
         * WHERE account_number = 'ACC-D601';
         * -- Expect: 1 row, CLOSED.
         * ===========================================================
         */
    }

    /// <summary>2. Undo is another update.</summary>
    private static async Task Scenario2_RestoreItAsync(SampleContext dbContext)
    {
        Step("2. Restore it");

        var byNumber = new ArxUpdateOptions { Match = ArxMatch.Key("account_number") };
        await dbContext.Service.UpdateAsync(Status("ACC-D602", "CLOSED"), byNumber);
        await dbContext.Service.UpdateAsync(Status("ACC-D602", "ACTIVE"), byNumber);
        Show("ACC-D602 closed, then active again");

        /* ===========================================================
         * [DIRECT QUERY CHECK]
         * -----------------------------------------------------------
         * SELECT account_number, status
         * FROM account
         * WHERE account_number = 'ACC-D602';
         * -- Expect: 1 row, ACTIVE.
         * ===========================================================
         */
    }
}

Expected output

What dotnet run printed when the sample was verified, on a freshly created sample schema. Ids differ when the tables already hold rows.

Output
  > 1. Close the account instead of deleting it
      ACC-D601 closed; its history stays
  > 2. Restore it
      ACC-D602 closed, then active again