Question

I have a class with a virtual property (public virtual List<Ingredients>), but in some cases I don’t want to get that data. How can I do this? I know about .Include and .Select, but if I do that, I need to change lots of code cause in my repository I return a Queryable and Service layer too.

Answer 1

An indirect answer: I would not expose IQueryable in a service layer. For (at least) three reasons:

• You must keep the context alive for when a navigation property is accessed.
• The layers that use your service layer can profoundly influence the SQL emitted to the database. You want to be in control of that that in your service or repository.
• Unit testing your service layer is very hard.

So if you expose IEnumerables of objects that you need in your application you can offer objects that have exactly those navigation properties loaded that are needed in a specific scenario. E.g. a maintenance function for product entities (name etc.) would get bare products only (and no code would ever access ingredients). A function that composes products from ingredients would get its ingredients as well. Service/repository methods should have parameters to specify what you need.

If you want 100% guarantee that lazy navigation properties are not going to be accessed you need to expose projected objects (or DTO’s) to your application.