Multi-async in Entity Framework 6?

Question

This is my code:

var banner = context.Banners.ToListAsync()
var newsGroup = context.NewsGroups.ToListAsync()
await Task.WhenAll(banner, newsGroup);
         


        

Answer 1

If you use Unity for dependency injection with for example repository pattern you will get the following error using two or more contexts with create/update/delete:

The relationship between the two objects cannot be defined because they are attached to different ObjectContext objects.

This can be solved using PerRequestLifetimeManager. More info here:

C# EF6 make multiple async calls to one context using Unity - Asp.Net Web Api

container.RegisterType(new PerRequestLifetimeManager());
container.RegisterType();
container.RegisterType();