System.Data.Linq.ChangeConflictException: Row not found or changed

Question

I am trying to delete a selected gridview row using LINQ (No LINQDataSource).

When the selection is changed, the detailsview binding is changed also. I can add a new

Answer 1

I just wanted to add my scenario for anybody who may have this issue.

We use a custom T4 against our Linq to SQL dbml. We basically just modified the original get/set of string properties to automatically trim and set null.

        get { return _OfficiantNameMiddle.GetValueOrNull(); }
        set 
        {
            value = value.GetValueOrNull();
            if (_OfficiantNameMiddle != value) 
            {
                _IsDirty = true;
                OnOfficiantNameMiddleChanging(value);
                SendPropertyChanging("OfficiantNameMiddle");
                _OfficiantNameMiddle = value;
                SendPropertyChanged("OfficiantNameMiddle");
                OnOfficiantNameMiddleChanged();
            }
        }

Legacy data in our database had some leading/trailing spaces so any concurrency check on these columns failed to result in a match (it was comparing the trimmed value against the non-trimmed database value). It was really easy to profile SQL, grab the SQL and start commenting out the items in the WHERE clause until it started returning a row during the concurrency check.

Luckily, we have a LastUpdatedOn field in our tables that is automatically set via OnValidate(System.Data.Linq.ChangeAction).

    partial void OnValidate(System.Data.Linq.ChangeAction action)
    {
        if (action == System.Data.Linq.ChangeAction.Insert)
        {
            CreatedBy = CurrentUserID;
            CreatedOn = DateTime.Now;
            LastUpdatedBy = CreatedBy;
            LastUpdatedOn = CreatedOn;
        }
        else if (action == System.Data.Linq.ChangeAction.Update)
        {
            LastUpdatedBy = CurrentUserID;
            LastUpdatedOn = DateTime.Now;
        }
    }

In order to bypass the problem, we just set the concurrency check to Never on all columns except the Primary Key columns and LastUpdatedOn column. This worked for us.