CODEWITHSUNDEEP
entity-frameworkdbcontext
Richard77
Richard77

Reputation: 21641

EF: How to enclose context object in a using statement?

Let's say I have the following classes Customer.cs, a context OfficeContext.cs, and a repository OfficeRepository.cs. Knowing that the context use a connection object, so it's advised to enclose it in a using statement:

public List<Customer> GetAllCustomersWithOrders()
{
   using(var oContext = new OfficeContext())
   {
      //Code here....
   }
}

My question is what if I want to re-use some of the code already in the repository? For instance, what if I want to display all the customers that ordered products but didn't receive them yet, do I need to duplicate the code?

public List<Customer> GetCustomersNotReceiveProducts()
{
  using(var oContext = new OfficeContext())
   {
      //Re-use GetAllCustomersWithOrders() here???...
   }
}

But as you can see, each time access a method, I also open instantiate a new context object. Is there any way to deal with that?

Upvotes: 0

Views: 126

Answers (1)

SBurris
SBurris

Reputation: 7448

What I do is have my repositories implement IDisposable.

Then have two constructors (one default) that instaniates a new context that holds it as a class level variable. And another constructor that takes a context and uses that internally.

The on the dispose of the class the context is disposed (if the current repository instatiated it).

This removes the context out of the method level and moves it to the class level. My functions keep everything in IQueryable so one function can call another function and perform additional refinements before the database it hit.

Exmaple:

public class MemberRepository : IDisposable
{
  OfficeContext db;
  bool isExternalDb = false;

  public MemberRepository()
  {
    db = new OfficeContext();
    isExternalDb = false;
  }

  public MemberRepository(OfficeContext db)
  {
    this.db = db;
    isExternalDb = true;
  }

  public IQueryable<Member> GetAllMembers()
      {
        var members= db.Members

        return members;
      }

  public IQueryable<Member> GetActiveMembers()
  {
    var members = GetAllMembers();
    var activeMembers = members.Where(m => m.isActive == true);
    return activeMembers;
  }

  public void Dispose()
  {
    if (isExternalDb == false)
    {
      db.Dispose();
    }
  }
}

Then where I use the repository, I do a using at that level:

using(var memberRepository = new MemberRepository())
{
   var members = memberRepository.GetActiveMembers();
}

Upvotes: 1

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