Update from EF 3.1.6 to EF 7.0.7

I recently updated the Microsoft.EntityFrameworkCore package from version 3.1.6 to 7.0.7.

I have noticed that with the new package in place, a DELETE statement is executed every time I add a new row to a table called Commands, and I cannot figure out why.

The source code has not changed. Before I present a lot of code, I will show you the specific method and the EF Core logger output. Maybe someone has an idea based on that.

Method

private async Task<int> AddCommandToDatabase(Tracker t, string msg, TrackerCommandType type)
{
    await _context.Commands.AddAsync(new Command()
    {
        CommandType = type,
        Timestamp = DateTime.Now,
        Message = msg,
        TrackerId = t.TrackerId,
        CommandDirection = CommandDirection.SENT,
        CommandStatus = CommandStatus.OPEN
    });

    return await _context.SaveChangesAsync();
}

(The Tracker reference comes from a table called [Trackers] not [TrackerConfig]).

Output for package in version 3.1.6:

SET NOCOUNT ON;

INSERT INTO [Commands] ([BatteryLevel], [CommandDirection], [CommandStatus], [CommandType], [Date], [DeviceStatus], [Message], [RollCounter], [StepCounter], [Time], [Timestamp], [TrackerId])
VALUES (@p0, @p1, @p2, @p3, @p4, @p5, @p6, @p7, @p8, @p9, @p10, @p11);

SELECT [CommandId]
FROM [Commands]
WHERE @@ROWCOUNT = 1 AND [CommandId] = SCOPE_IDENTITY();

Output from package in version 7.0.7:

SET NOCOUNT ON;

INSERT INTO [Commands] ([BatteryLevel], [CommandDirection], [CommandStatus], [CommandType], [Date], [DeviceStatus], [Message], [RollCounter], [StepCounter], [Time], [Timestamp], [TrackerId])
OUTPUT INSERTED.[CommandId]
VALUES (@p0, @p1, @p2, @p3, @p4, @p5, @p6, @p7, @p8, @p9, @p10, @p11);

DELETE FROM [TrackerConfig]
OUTPUT 1
WHERE [TrackerConfigId] = @p12;

I would appreciate any ideas or suggestions. Thank you.

Thanks to Panagiotis Kanavos and Svyatoslav Danyliv, I was able to identify the issue. It turned out to be an anti-pattern. To facilitate serialization, I had set an FK (foreign key) property (aka related entity) to null.

This behavior wasn't a problem when using ServiceLifetime.Scoped, but I recently switched to ServiceLifetime.Singleton and forgot it. Consequently, when I call SaveChangesAsync, EF Core deletes the entity without the required FK.

As a result, I mistakenly attributed the issue to the new library.

For future readers, here are at least three better ways to handle this situation:

1. Use projection to an accurate ViewModel using .Select(...)
2. Utilize AsNoTracking()
3. Alternatively, use the [JsonIgnore] attribute.