Design pattern related to Entity Framework

Factory Method, an Entity Framework ObjectContext provides a CreateObjectSet<T> method, which creates an ObjectSet<T> for the given type. Since those object-sets are the main approach to access the entities within a context, I would say it is also a very important pattern used in EF. Proxy, obviously EF dynamically creates proxy-types for your entities (unless you tell it not to, or it can't create a proxy because a class is sealed or does not qualify as a "proxyable" type). Decorator, this might be a bit far fetched, but to implement lazy-loading in proxy-types, the property-getters of navigation-properties are overloaded, to perform the lazy-loading until requested. This is handled in the proxy type, but also depends on whether lazy-loading is enabled and the navigation-property itself. Interpreter, EF introduced Entity-SQL which is a somewhat generalized form of SQL that also has knowledge of the object-orientied entities. You can define a those queries as strings which are then interpreted by EF and turned into provider-dependend SQL. Strategy, looking at the various overloads of the ObjectContext.SaveChanges method, you can select from different strategies that are used to determine changes made on known entities. Memento, the ObjectStateManager keeps track of changes made to the entities and can be used to access those information including the original-values. Facade, exposing entity-sets as IQueryable should qualify as "a simplified interface to a large body of code", since turning such expressions into Entity SQL and than provider-specific SQL is a big deal. Observer, ObjectContext provides two eventy ObjectMaterialized and SavingChanges. Since .NET events are an implementation of the observer-pattern, EF also qualifies for this one. We can find a lot of places where EF actually implements those patterns. But since the book is out for nearly 20 years, you can expect that some of these patterns are considered a standard, which isn't worth mentioning. For example the Observer pattern or the Iterator pattern (which haven't mentioned, just because IQueryable implements IEnumerable).