Update master with sum record of details

See more:

C#

MVC4

CRUD

entity-framework

hello

how i can updating total of master when each one detail have been inserted /updated/deleted, and not all details of master?

if i used repository for master and repository of details, and if these repositories implements IDisposable, how to use the tow repositories with each their save methode to updating master total with unitprice of this detail in class BLL?

What I have tried:

i have created solution in visual studio 2012 and this solution is layred in 4 project :

1. project presentation layer (asp.net mvc)

2. business entities layer

public class Master
{
    public int Id {get; set;}
    public decimal TotalPrice {get; set;}
   //the rest of properties
    public private ICollection<Detail> Details {get; set;}
}

public class Detail
{
   public int Id {get; set;}
   public decimal UnitePrice {get; set;}
   //the rest of properties
   public int MasterId {get; set;}
   public private Master Master {get; set;}
}

3. data access layer (ado.net data model entity framework + repositories)

public class MasterRepository : IMasterRepository{
//code of class to implemente GetAll + CRUD for master
}


public class DetailRepository : IDetailRepository{

    EFContext context = new EFContext();

    //Get the details for one master

    public IEnumerableDetail GetAllDetailsByMasterId(int masterId)
    {
       var query = context.Details.Where(d=>d.MasterId == masterId)
    }

   //the rest of code to implemente CRUD of details

}

4. but for business logic layer in classes Bll i try to calculate the total of the master by sum of unit prices for the details

public class MasterDetailsBll
{

    public decimal GetTotal(){

   //call the methode GetAllDetailsByMasterId of DetailRepository thet return 
    //enumerebal<detail> and then call the extention methode Sum for calculate 
    // the sum of unite prices of detail
  
       using (var repository = new DetailRepository())
       {       
          var total = reopsitory.GetAllDetailsByMasterId(masterId).Sum(d=>d.UnitePrice);
       }

      //call the CRUD Mehodes of repositoryMaster and CRUD of the repositoryDetails
    }
}

I would be grateful if you helped me

goodby soon