Entity Framework - Where is my Object Context?

余生颓废 提交于 2019-12-06 17:17:33

问题


Ok, I'm obviously missing something very basic. I'm very new to Entity Framework.

I want to call stored procedures without importing them, so I was planning on using ExecuteStoreQuery(). According to the documentation, ExecuteStoreQuery is a method of ObjectContext. But, I have no idea where to get my ObjectContext.

I generated my entites using Database First. So far, I have been accessing my entities something like this:

var db = new MyEntities();

PRODUCT p = db.PRODUCTS.First(a => a.PRODUCTSKEY == thekey);

But I can't call db.ExecuteStoreQuery, becase db isn't an ObjectContext.

I've googled how to get ObjectContext from an entity. I find some answers, but they're all flagged with cautions, saying that it's a workaround, and only to use it if you have no other option. Ok, so what is the RIGHT way?

All examples that I've found for using ExecuteStoreQuery assume that you already have your ObjectContext. Not very helpful.

I found one website that stated that the ObjectContext is "automatically generated" by Entity Framework. If that's the case, then where is it?

I'm obviously missing something very simple here. This can't be that difficult.


回答1:


To get to the ObjectContext of your DbContext, all you'd need to do is the following:

var objectContext = ((IObjectContextAdapter)myDbContextObject).ObjectContext;



回答2:


ObjectContext was replaced by DbContext in Entity Framework 4.1. Actually DbContext is an adapter (wrapper) over ObjectContext. If you need to get ObjectContext you can cast your DbContext instance to IObjectContextAdapter interface (it is implemented explicitly) and wrapped ObjectContext instance will be available:

ObjectContext context = ((IObjectContextAdapter)db).ObjectContext;

BTW I think you are looking for db.Database.SqlQuery method.




回答3:


In Your case MyEntities is your ObjectContext.

Technically it is auto-generated class by EntityFramework that inherits from ObjectContext class.



来源:https://stackoverflow.com/questions/14245153/entity-framework-where-is-my-object-context

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