Web API - Entity Framework is trying to ruin my life - asp.net-mvc

Question

I have a simple database with five tables bound together by relationships. I've built OData apps before and like the model, but wanted to make the leap to Web API. The problem is - when I make my call to the ProductType table for example - it returns EVERY record in every table! What gives?
My goal is to call a ProductType for example like this:
url/api/ProductType
(and the usual getbyId, delete, etc)
I'm using the repository pattern, and following these steps:
1. Create a Entity Framework model with the tables I want to display. Yawn.
2. Add an interface in Models, call it IProductTypeRepository, with the behaviors I want to see.
3. Add a model class (ProductModel.cs) that inherits from this interface
4. Make sure Global.asax has either default api setup or there’s a App_Start\Routeconfig and WebApiConfig class.
5. Surgery on the ValuesController class.
Maybe this is in ignorance of how WebAPI is supposed to work with relationships. Perhaps the goal is to do one call to a service - and get EVERY record across multiple tables (for example, Product and ProductDetails). If so, I think the documentation could have been a LOT clearer on this point!
============================CODE FOLLOWS!================================================
I’m going to skip the EF auto-generated code obviously – but suffice to say it contains entities and joins for five tables – ProductType, Location, Process, Step, and StepType. ProductType is a very simple table with an ID field and a description and a part # field (MaterialMasterId).
For IProductTypeRepository, here is my code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Perceptive.Services.Models
{
interface IProductTypeRepository
{
IEnumerable<ProductType> GetAll();
ProductType GetById(int ProductTypeID);
int Update(ProductType producttype);
ProductType Add(ProductType producttype);
void Delete(int ProductTypeId);
}
}
For ProducTTypeModel:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace Perceptive.Services.Models
{
public class ProductTypeModel : IProductTypeRepository
{
private PCSEntities1 context = new PCSEntities1();
public IEnumerable<ProductType> GetAll()
{
return context.ProductTypes;
}
public ProductType GetById(int ProductTypeId)
{
IQueryable<ProductType> producttypes = context.ProductTypes.Where(a => a.ProductTypeID == ProductTypeId);
return producttypes.FirstOrDefault();
}
public int Update(ProductType producttype)
{
ProductType updateProductType = context.ProductTypes.FirstOrDefault(c => c.ProductTypeID == producttype.ProductTypeID);
updateProductType.Description = producttype.Description.Trim();
updateProductType.MaterialMasterID = producttype.MaterialMasterID;
return context.SaveChanges();
}
public ProductType Add(ProductType producttype)
{
var addedProductType = context.ProductTypes.Add(producttype);
context.SaveChanges();
return addedProductType;
}
public void Delete(int producttypeid)
{
ProductType producttype = context.ProductTypes.FirstOrDefault(a => a.ProductTypeID == producttypeid);
context.ProductTypes.Remove(producttype);
context.SaveChanges();
}
}
}
… and lastly, my Controller – ProductTypeController.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
//dh added
using Perceptive.Services.Models;
namespace Perceptive.Services.Controllers
{
public class ProductTypeController : ApiController
{
IProductTypeRepository repository = new ProductTypeModel();
// GET /api/Producttype
[HttpGet]
public IEnumerable<ProductType> Get()
{
return repository.GetAll();
}
// GET /api/Producttype/5
[HttpGet]
public ProductType Get(int id)
{
ProductType producttype = repository.GetById(id);
return producttype;
}
// POST /api/ProducTtype
[HttpPost]
public void PostProductType(ProductType producttype)
{
repository.Add(producttype);
}
// PUT /api/ProductType
// DH seems scanty here. Where's the repository put?
[HttpPut]
public void PutProductType(ProductType producttype)
{
if (repository.Update(producttype) == 0)
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}
}
//DELETE /api/ProductType/5
[HttpDelete]
public void Delete (int id)
{
repository.Delete(id);
}
}
}

Answer 1

You need to use IQueryable:
interface IProductTypeRepository
{
IQueryable<ProductType> GetAll();
ProductType GetById(int ProductTypeID);
int Update(ProductType producttype);
ProductType Add(ProductType producttype);
void Delete(int ProductTypeId);
}
When you use IEnumerable it is going to pull all the records in the entity client side and then work on them. IQueryable is treated as a query until you call an action like .ToList() which will execute the query and pull the results to the client.