EntityFramework.dll 中发生“System.Data.Entity.Infrastructure.DbUpdateException”

Question

I wrote a rather simple code (client server based on WCF and Windows form). i was trying to update the db so that i could test my code and i encounterd the above exception. Any ideas how to solve it?

      // For testing 
      public void updateTable() 
      {
        using (var db = new overlayDBEntities())
        {
            var overlaydb = new overlayData
            {
                DeviceId = "1111",
                TimestampUTC = new DateTime(1990, 1, 1, 9, 9, 9),
                OverlayData1 = "Random Text"
            };

            db.overlayData.Add(overlaydb);

            try
            {
                db.SaveChanges();
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            var overlaydb1 = new overlayData
            {
                DeviceId = "1111",
                TimestampUTC = new DateTime(2000, 2, 2, 10, 10, 10),
                OverlayData1 = "seconed seconed seconed "
            };

            db.overlayData.Add(overlaydb);

            try
            {
                db.SaveChanges();
            }
            catch (Exception ec) 
            {
                Console.WriteLine(ec.Message);
            }
        }
    }

Answer 1

If you need to update Row if already Exists in database so dont use context.Add();you can use as follows.

    var overlaydb1 = new overlayData
    {
      DeviceId = "1111",
      TimestampUTC = new DateTime(2000, 2, 2, 10, 10, 10),
      OverlayData1 = "seconed seconed seconed "
    };

    try
    {
      db.overlayData.Attach(overlaydb1);
      db.ObjectStateManager.ChangeObjectState(overlaydb1, EntityState.Modified);
      db.SaveChanges();
    }

    catch (Exception ec) 
    {
      Console.WriteLine(ec.Message);
    }

Answer 2

当用户忘记在特定表中添加Primery key然后通过应用程序添加数据时，也会出现同样的错误。

Answer 3

I think the problem is the type of your datetime. sqlsever has more than one datetime. if you check your inner exception, you may see the type that you are trying to put in your table and the type it actually needs. conversion cant be done automatically and you should change it in the table or convert it in your code. it can be datetime, datetime2 (7), etc.

Answer 4

According to Lan,

"The error message details all that you need to know:

Additional information: The model backing the 'AppraisalDBContext' context has changed since the database was created.Consider using Code First Migrations to update the database ( http://go.microsoft.com/fwlink/ ?

It means one of your classes use in the AppraisalDBContext has changed, but the database hasn't been updated so is now out of date. You need to update this use Code First migrations."

From The Original Post

Answer 5

Multiple records of data with the same primary key overlap when add , causing the same error

You should review your primary key settings

Answer 6

In my case, i have errors while generate model (.edmx file) and entities (.tt file). Regenerate it solve the problem

Answer 7

using Code first approach .
How to define primary key in Web API.

Eg:- Model Class
  public class Categories
    {
        [Key]
        public int cateId { get; set; }
        public string cateName { get; set; }
    }
Controller Class:-  Categories Controller
 public bool AddCate(Categories preg)
        {            
            db.Categories.Add(preg);
            db.SaveChanges();
            return true;
        }
Context Db Class
  public System.Data.Entity.DbSet<TestingWebApi.Models.Categories> Categories { get; set; }
 Error:-"System.Data.Entity.Infrastructure.DbUpdateException",

Answer 8

Below is the procedure to solve the System.Data.Entity.Infrastructure.DbUpdateException. Please follow the instructions.

Happy Coding !!!

https://msdn.microsoft.com/en-us/data/dn579398.aspx

Best Regards, Thet Tin Oo