Repository Pattern Standardization of methods
- by Nix
All I am trying to find out the correct definition of the repository pattern.
My original understanding was this (extremely dubmed down)
Separate your Business Objects from your Data Objects
Standardize access methods in data access layer.
I have really seen 2 different implementations.
Implementation 1 :
public Interface IRepository<T>{
List<T> GetAll();
void Create(T p);
void Update(T p);
}
public interface IProductRepository: IRepository<Product> {
//Extension methods if needed
List<Product> GetProductsByCustomerID();
}
Implementation 2 :
public interface IProductRepository {
List<Product> GetAllProducts();
void CreateProduct(Product p);
void UpdateProduct(Product p);
List<Product> GetProductsByCustomerID();
}
Notice the first is generic Get/Update/GetAll, etc, the second is more of what I would define "DAO" like.
Both share an extraction from your data entities. Which I like, but i can do the same with a simple DAO. However the second piece standardize access operations I see value in, if you implement this enterprise wide people would easily know the set of access methods for your repository.
Am I wrong to assume that the standardization of access to data is an integral piece of this pattern ?
Rhino has a good article on implementation 1, and of course MS has a vague definition and an example of implementation 2 is here.
