Question

I’m trying to use Entity Framework to query database and I have following code that I’m using to get some data.

var students= MyEntities.Students.Where(s => s.Age > 20).ToList();

This code works fine and returns correct data. However, if I run this code, then go to database and update records to change the data this code should return, and then re-run this code without shutting down the app, I’m getting original data.
I’m pretty sure it used to work fine, but now this doesn’t refresh data.

Answer 1

No it never worked. This is essential behavior of entity framework (and many ORM tools) called identity map (explanation here).

If you run the query on the same context you will not get your entities updated. It will only append new entities created in the database between running those two queries. If you want to force EF to reload entities you must do something like this:

ObjectQuery query = MyEntities.Students;
query.MergeOption = MergeOption.OverwriteChanges;
var students = query.Where(s => s.Age > 20).ToList();