asp.net entity framework tutorial part- 12
http://www.jquell.com/ Handling Concurrency in an ASP.NET web application
In this video I will show you technique for handling concurrency in an ASP.NET web application that uses the Entity Framework. A concurrency conflict occurs when one user edits a record and another user edits the same record before the first user's change is written to the database. to solve problem we are going to use optimistic concurrency. Optimistic concurrency means allowing concurrency conflicts to happen, and then reacting appropriately. In the Entity Framework, you can resolve conflicts by handling OptimisticConcurrencyException that the Entity Framework throws. In order to know when to throw these exceptions, the Entity Framework must be able to detect conflicts. Therefore, we must configure the database and the data model appropriately