Update Database using Entity Framework having primary key on multiple Columns

Question

Following is the error message I get:

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=472540 for information on understanding and handling optimistic concurrency exceptions.

My model consists of few columns, among them two columns which make up the primary key clustered:

[Key]
[Column(Order = 0)]
public string SourceName { get; set; }
[Key]
[Column(Order = 1)]
public string SourceType { get; set; }

Code to update using Entity Framework:

 _Entities.SourceInfoes.Attach(entity);
 _Entities.Entry(entity).State = EntityState.Modified;
 _Entities.SaveChanges();

Can some one help me on how to solve the exception above?

is your "Update" function in any for loop or timers? Most of the time, I noticed this error occurs when _Entities.SaveChanges() is currently being executed (but not completed yet) and at the same time, there might be either EF READ is taking place to same row (same record) . Its hard to help with these code snippets. — sam
Maybe optimistic concurrency was actually configured and entity is attached without (or with an expired) concurrency token. Not enough details to answer this question. — Gert Arnold

Nic Nic · Accepted Answer · 2015-04-01T22:27:10

Before saving your changes, are you making sure that all not-null properties have a value?

In my case I had to add a hidden value in the view, so the primary key would be posted back to the server.

@Html.HiddenFor(model => model.Id)

Update Database using Entity Framework having primary key on multiple Columns

2 Answers