Entity Framework v8, on SaveChangeAsyc() intserts record twice

Question

Entity Framework v8, on SaveChangeAsyc() intserts record twice

Reema George Dass 20

  public async Task AddAsync<T>(T entity) where T : class
  {
      await _dbContext.Set<T>().AddAsync(entity); // use only context and test
      await _dbContext.SaveChangesAsync();
}

On SaveChangesAsync() 1 duplicate record is inserted.

Accepted answer

0 additional answers

Your answer

Answer 1

Anonymous

Hi, @Reema George Dass. Welcome to Microsoft Q&A.

I am using version 8.0.0 of Entity Framework Core. In my test, the code you provided could be added correctly and is not added twice by mistake.

Please do the following test:

1.Assuming that you are using a database in Visual Studio 2022 and have turned off the auto-increment of the primary key in the table (here is Identity). Then when you execute the AddAsync method, the entity passed in must specify the Id.

YourEntity entity = new YourEntity() { Id = 1, Name = "AA" };

2.Suppose you have turned on the auto-increment of the primary key in the table.

Then when you execute the AddAsync method, the entity passed in should not specify the Id.

YourEntity entity = new YourEntity() {  Name = "AA" };

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Reema George Dass 20 Reputation points

2025-03-13T08:51:33.0066667+00:00

Hello, Thank you for your response, I have the ID on Auto increment. and the values is not being passed its a default: 0 , I have tried, async and Sync methods but the issue persists. DBrecords:energy_data=# select * from "Devices";

Id | Pod | Direction

----+-----------------------------------+-----------

1 | AT009000000000000000056789800E | 1

2 | AT009000000000000000056789800E | 1

same Pod: AT009000000000000000056789800E added twice again

(2 rows)
Anonymous

2025-03-13T08:57:33.96+00:00

Hi, @Reema George Dass.

Could you provide minimal reproducible code?

Reema George Dass 20

Method Call:

public async Task InsertionToDatabase()
{ 
if (device == null)
{
    device = _mapper.Map<Device>(deviceDto);
    await _datarepo.AddAsync(device); 
    device = await _datarepo.GetDeviceByPoDAsync(deviceDto.Pod);
}
else
{
    // Device already exists, skip adding and log
    _logger.LogInformation($"Device with PoD {deviceDto.Pod} already exists, skipping insert.");
}
}

Mapper:

public class MappingProfile : Profile
    {
        public MappingProfile()
        {
            CreateMap<DeviceDTO, Device>()
                .ForPath(dest => dest.Id, opt => opt.Ignore()); // tried with n without this line
            CreateMap<DeviceDataDTO, DeviceData>() // second table( not in question for the error atm)
            .ForMember(dest => dest.TimestampUtc, opt => opt.MapFrom(src =>
                DateTime.SpecifyKind(src.TimestampUtc, DateTimeKind.Utc))
            );
        }
    }
}

Models:

[Table("Devices")]
public class Device
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity), Key, Required]
    public long Id { get; set; } // auto incremented on insertion
    [MaxLength(33)]
    public required string Pod { get; set; }
    [Required]
    public EnergyDirection Direction { get; set; }
}

DB_insertion:

  public async Task AddAsync<T>(T entity) where T : class
   {
       await _dbContext.Set<T>().AddAsync(entity); 
       await _dbContext.SaveChangesAsync();
   }

On debug: I see two records populated at SaveChanges()

Please refer the previous comment.

Things I have tried:

To use specific model type addition and not Set<T>().
Sync method with SaveChanges()
few more that dint make differences from stack overflow.

I was following this: https://github.com/PomeloFoundation/Pomelo.EntityFrameworkCore.MySql/issues/1621

This thread talks about the same issue in older frame works which is not consistent.

The job that is triggering the first method:

// Add Logging
builder.Logging.ClearProviders();
builder.Logging.AddConsole();
// Quartz services
builder.Services.AddQuartz(q =>
{
    // Define the job
    var jobKey = new JobKey("DatabaseInsertionScheduler");
    q.AddJob<DatabaseInsertionScheduler>(opts => opts.WithIdentity(jobKey));
    // Define a trigger using a Cron expression (every minute)
    //    q.AddTrigger(opts => opts
    //        .ForJob(jobKey)
    //        .WithIdentity("DatabaseInsertionScheduler")
    //        .WithCronSchedule("0 * * * * ?")); // Runs every minute
    q.AddTrigger(opts => opts
            .ForJob(jobKey)
            .WithIdentity("DatabaseInsertionScheduler")
            .StartNow()  // Trigger immediately when the app starts
            .WithSimpleSchedule(x => x.WithRepeatCount(0)) // No repeat, run once
        );
});
// Register the Quartz hosted service
builder.Services.AddQuartzHostedService(options => options.WaitForJobsToComplete = true);

The trigger:


// Trigger the job manually after the app starts For testingusing (var scope = app.Services.CreateScope()){    var scheduler = await scope.ServiceProvider.GetRequiredService<ISchedulerFactory>().GetScheduler();    var jobKey = new JobKey("DatabaseInsertionScheduler");    if (await scheduler.CheckExists(jobKey))    {        Console.WriteLine("Manually triggering DatabaseInsertionScheduler job...");        await scheduler.TriggerJob(jobKey);        Console.WriteLine("Job triggered successfully!");    }    else    {        Console.WriteLine("Job not found!");    }}

Reema George Dass 20 Reputation points

2025-03-13T09:21:08.7333333+00:00

Kindly let me know if you would require anything more. Appreciate the help!! :-)
Anonymous

2025-03-14T01:15:03.96+00:00

Hi, @Reema George Dass.

Is your current problem solved?
Anonymous

2025-03-14T03:15:13.0066667+00:00

Hi, @Reema George Dass.

In your project, have you used all the codes you provided? You seem to have intentionally let DatabaseInsertionScheduler execute twice. (Once at the beginning of the program, and once manually called later)

You could output a log for the execution of AddAsync to determine whether the program issued two insert commands or the database executed two inserts through a trigger in one insert command.

Share via

Entity Framework v8, on SaveChangeAsyc() intserts record twice

0 additional answers

Your answer