Question

My understanding of the Entity Framework is that if it can answer a query from its cache, it will. My simple testing, however, shows repeated queries hit the database even though they were previously answered positively:

var u1 = context.Users.SingleOrDefault(u => u.Id == 1);
var u2 = context.Users.SingleOrDefault(u => u.Id == 1);

These queries are successful. For each, I see a SELECT TOP (2) in SQL Profiler.

Why does EF go to the database for that second query?

Answer 1

Well, because EF doesn’t use caching. nHibernate does. Here article on how to enable caching with EF.

Edit: EF doesn’t have transparent out-of-the-box cache. But it has explicit cache within unit of work: ObjectContext.GetObjectByKey