Repository Pattern: SaveOrUpdate() in Entity Framework and L2S

These web articles uses separate Save() and Update() methods for saving and upd开发者_运维百科ating an entity.

How can I write a SaveOrUpdate() method in Entity Framework with the help of ObjectContext and in Linq-To-SQL with the help of DataContext?

That is, how can I write a single method that shall do both save and update job?

Try looking at the Unit of Work pattern - Angry.Net Developer, ADO.NET team blog