Concurrency Exception While adding Record

Kmcnet 691

Hello everyone and thanks for the help in advance. I am using Entity Framework Core in a MVC application to add a record to a Sql database, however I continue to receive the error message "The database operation was expected to affect 1 row(s), but actually affected 0 row(s); data may have been modified or deleted since entities were loaded". This particular table is only being accessed by this one application that only adds records. Here is my code:

                using (var ctx = new myDbContext())
                {
                    ctx.tbl_Log_UserActivity.Add(new tbl_Log_UserActivity()
                    {
                        IPAddress = ipAddress,
                        Referer = Referer,
                        UserAgent = userAgent,
                        TimeEntered = DateTime.Now
                    });
                    ctx.SaveChanges();

                }

When this didn't work I tried:

                    var userActivity = new tbl_Log_UserActivity()
                    {
                        IPAddress = ipAddress,
                        Referer = Referer,
                        UserAgent = userAgent,
                        TimeEntered = DateTime.Now
                    };

                    ctx.tbl_Log_UserActivity.Add(userActivity);

                    ctx.SaveChanges();

I receive the same error either way. Any help would be appreciated.

Zhi Lv - MSFT 32,011 Reputation points Microsoft Vendor

2022-05-06T01:48:57.613+00:00
Hi @Kmcnet ,

The shared code is correct. According to them, I create a sample on my side, everything works well. On my side, the tbl_Log_UserActivity class like this:

public class tbl_Log_UserActivity { [Key] public int Id { get; set; } public string IPAddress { get; set; } public string Refer { get; set; } public string UserAgent { get; set; } public DateTime TimeEntered { get; set; } }

What about your tbl_Log_UserActivity looks like? Besides, please check the ApplicationDbContext's OnModelCreating method, have you ever set he default value for the tbl_Log_UserActivity's property?

Can you share the tbl_Log_UserActivity class and the code in the OnModelCreating method, or create a minimal sample to reproduce the problem then shared with us via Github or OneDrive, then it is easier for us to help you fix it.

Best regards,
Dillion