CODEWITHSUNDEEP
c#.netentity-framework
user1765862
user1765862

Reputation: 14145

working with entity and repository

let's say that I have some IBookRepository. And besides ravendb I want to add SqlServer implementation of IBookRepository called SQLServerRepository.

What is the proper way to create implemenation of this interface having db context in mind. Should I pass dbcontext as parameter inside SQLServerRepository constructor and populate class member dbcontext to work with db?

public class SQLServerBookRepository : IBookRepository
{
   private MyDBContext _db;
   public SQLServerRepository(MyDBContext db)
   {
      _db = db;
   }
   public void AddBook(Book b){
      // adding book to context
      _db.SaveChanges();
   }
}

I'm asking is this proper way? Is there are better way? Where should I store dbcontext in the same layer with repository, dao layer, how would you do it?

Upvotes: 0

Views: 109

Answers (2)

Alex
Alex

Reputation: 13224

Yes, the proper way is not to do this. The "Repository" pattern as an additional layer over a library that already abstracts the database is an anti-pattern.

Furthermore, the paradigms of a document database like RavenDB and a relational database are very different. You would not solve / model your solutions in the same way.

Refer to this blog post "RavenDB and the Repository pattern", by a user of RavenDB who had similar intentions as you expressed, summarizing a discussion between himself and Ayende Rahien (aka Oren Eini), the creator of RavenDB.

Regarding your follow up "what if" question, related to creating a repository for EF. My advice would be the same: don't.

Entity Framework is already abstracting the database for you. It provides its own versions of a "Repository" as a DbSet and a "unit of work" as the DbContext. Don't put another abstraction layer over it that will always be:

  1. suboptimal because now you can't access the underlying full API and
  2. leaky.

Upvotes: 1

Mike Cole
Mike Cole

Reputation: 14713

I generally manage DataContext lifetime outside of my repositories. I use my IoC tool (usually structuremap) to scope context to HttpContext. Then I simply inject an instance of my DataContext into my repositories.

Upvotes: 1

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