Export (0) Print
Expand All

How to: Detect and Resolve Conflicting Submissions (LINQ to SQL)

LINQ to SQL provides many resources for detecting and resolving conflicts that stem from multi-user changes to the database. For more information, see How to: Manage Change Conflicts (LINQ to SQL).

The following example shows a try/catch block that catches a ChangeConflictException exception. Entity and member information for each conflict is displayed in the console window.

NoteNote:

You must include the using System.Reflection directive (Imports System.Reflection in Visual Basic) to support the information retrieval. For more information, see System.Reflection.

// using System.Reflection;
Northwnd db = new Northwnd(@"c:\northwnd.mdf");

Customer newCust = new Customer();
newCust.City = "Auburn";
newCust.CustomerID = "AUBUR";
newCust.CompanyName = "AubCo";
db.Customers.InsertOnSubmit(newCust);

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);
        }
    }
}
catch (Exception ee)
{
    // Catch other exceptions.
    Console.WriteLine(ee.Message);
}
finally
{
    Console.WriteLine("TryCatch block has finished.");
}

Community Additions

ADD
Show:
© 2014 Microsoft