c# - Data Conflict in LINQ

Question

When making changes using SubmitChanges(), LINQ sometimes dies with a ChangeConflictException exception with the error message Row not found or changed, without any indication of either the row that has the conflict or the fields with changes that are in conflict, when another user has changed some data in that row.

Is there any way to determine which row has a conflict and which fields they occur in, and also is there a way of getting LINQ to ignore the issue and simply commit the data regardless?

Additionally, does anybody know whether this exception occurs when any data in the row has changed, or only when data has been changed in a field that LINQ is attempting to alter?

Answer 1

Here's a way to see where the conflicts are (this is an MSDN example, so you'll need to heavily customize):

try
{
    db.SubmitChanges(ConflictMode.ContinueOnConflict);
}
catch (ChangeConflictException e)
{
    Console.WriteLine("Optimistic concurrency error.");
    Console.WriteLine(e.Message);
    Console.ReadLine();
    foreach (ObjectChangeConflict occ in db.ChangeConflicts)
    {
        MetaTable metatable = db.Mapping.GetTable(occ.Object.GetType());
        Customer entityInConflict = (Customer)occ.Object;
        Console.WriteLine("Table name: {0}", metatable.TableName);
        Console.Write("Customer ID: ");
        Console.WriteLine(entityInConflict.CustomerID);
        foreach (MemberChangeConflict mcc in occ.MemberConflicts)
        {
            object currVal = mcc.CurrentValue;
            object origVal = mcc.OriginalValue;
            object databaseVal = mcc.DatabaseValue;
            MemberInfo mi = mcc.Member;
            Console.WriteLine("Member: {0}", mi.Name);
            Console.WriteLine("current value: {0}", currVal);
            Console.WriteLine("original value: {0}", origVal);
            Console.WriteLine("database value: {0}", databaseVal);
        }
    }
}

To make it ignore the problem and commit anyway:

db.SubmitChanges(ConflictMode.ContinueOnConflict);