Entity Framework Best Practices In Business Logic?

Question

I am using the Entity framework for the first time, and would like to know if I am using in the best practice.

I have created a separate class in my business logic

Answer 1

In my experience this code is not good, because you lose the capacity to navigate relationships through navigation properties.

public List  getArticles( ){  
    using (var db = new ArticleNetEntities())
    {
        articles = db.Articles.Where(something).ToList();
    }
}

Using this approach you can't use the following code because a.Members is always null( db context is close and cant get data automatically).

var articles = Data.getArticles();
   foreach( var a in articles ) {
       if( a.Members.any(p=>p.Name=="miki") ) {
           ...
       }
       else {
           ...
       }
    }
}

Using only a global db context is a bad idea because you must use a delete changes function

in a point of your application yo do this but don't save changes and close the window

var article= globalcontext.getArticleByID(10);
article.Approved=true;

then in another point of application you make some operation and save

//..... something
globalcontext.saveChanges();

in this case previous article approved property is set to modified by entity framework. When you save, approved is set true!!!

Best approach for me is use 1 context per class You can pass context to another external method if you need

class EditArticle {

    private DbEntities de;
    private currentAricle;

    public EditArticle() {
        de = new DbEntities; //inizialize on new istance
    }

    loadArticleToEdit(Articele a){
        // a is from another context 
        currentArticle= de.Article.Single(p=>p.IdArticle==a.IdArticle){
    }

    private saveChanges(){
        ...
        pe.saveChanges();
    }
}