REST Web服务-实体框架是否过大？

Question

I'm familiar with the EF and it looks pretty cool. As far as I can see, it is basically a LINQ to SQL with extra functions (like caching, automatic connection handling and so on). However, in my opinion EF is useful for those applications that directly comminicate with the model data (~persistence).

In case of writing a RESTful web service, we are reading and writing objects (for example) in JSON format. The application calls the web service with some data and it returns data back.

That's why I'm actually thinking on not using EF because it looks like an overkill for me. Since I'm not planning to expose the actual model, I would use DTOs instead (both as input and output of a web service call). This means that I have to do the mapping to the underlying model anyway so the EF would be used as a LINQ to SQL wrapper.

Is there anything I'm missing? Is there any feature that would be useful while writing a RESTful web service? is there any benefit from using EF instead of LINQ to SQL?

Answer 1

So the logic here is that you aren't exposing your entities past the data layer, so EF is pointless.

I never expose my EF Entities pass the business layer, just one layer down from the data layer. I always project them to ViewModels and Models which are just POCOs. I've seen this in lots of projects.

Rarely do I actually use the entity change tracking features. By the time a GET/POST has occurred it doesn't make sense to requery the entities on the POST just so you can update them via change tracking. Instead a direct update makes more sense and avoids an unnecessary roundtrip to the database.

My point being is in what I've seen it most commonly used, the EF models are not exposed past more than one layer in most cases. This ensures View/UI layers don't accidentally modify EF state or cause lazy loading(which is usually disabled).

However I still get to leverage the great EF/DB mapping layer and EF LINQ queries, which is by far the greatest features of EF.

Most alternatives such as Dapper are just that, a framework for executing queries.

So I wouldn't fallback to just doing ADO.NET or an older query technology just because you aren't using all the features of EF. You should still use a modern query framework such as EF or Dapper, simply because you are still executing queries. Just because you aren't exposing the entities doesn't change that.