Concurrency with Linq To Sql and ASP.NET

Question

What is the best way to check for concurrency issues when using LINQ to SQL in an ASP.net application.

In my application, I am retrieving a record from the database and displaying the fields in editable textboxes. Then the datacontext is thrown away.

How should I save the entity object so that I can use L2Sql's built in concurrency features? I can't save the object in session and reattach it to a new datacontext: l2s complains that the object is not new.

The LinqDataSource manages to do this somehow. Does anyone know how?

Answer 1

The way the optimistic concurrency in Linq2Sql works is that it stores the original values and compares them on insert.

If you throw the datacontext away you loose the original values.

What i usually do is to load the object form the database once more when i'm about to save, then modify that object with the values from the form.