如何将我的存储库从EF代码优先转换为使用EDMX实体模型？

Question

Currently my repositories consist of the following code:

public interface IRepository<T> where T : class
{
    T Get(int id);
    IQueryable<T> GetAll();
    IQueryable<T> Where(Expression<Func<T, bool>> predicate);
    IQueryable<T> Query();
    void Add(T entity);
    void Remove(T entity);
    void Save();
}

public class Repository<T> : IRepository<T> where T : class
    {
        private readonly IContextProvider  _ctxProvider;
        protected BaseModelContext _ctx
        {
            get
            {
                return _ctxProvider.DataContext;
            }
        }

        public Repository(IContextProvider ctx)
        {
            _ctxProvider = ctx;
        }

        public T Get(int id)
        {
            return _ctx.Set<T>().Find(id);
        }

        public IQueryable<T> GetAll()
        {
            return _ctx.Set<T>();
        }

        public IQueryable<T> Where(Expression<Func<T, bool>> predicate)
        {
            return _ctx.Set<T>().Where(predicate);
        }

        public void Add(T entity)
        {
            _ctx.Set<T>().Add(entity);
        }

        public void Remove(T entity)
        {            
            _ctx.Set<T>().Remove(entity);
        }

        public IQueryable<T> Query()
        {
            return _ctx.Set<T>().AsQueryable();
        }

        public IQueryable<T> Eager(string path)
        {
            return _ctx.Set<T>().Include(path);
        }

        public void Save()
        {
            _ctx.SaveChanges();
        }
    }

I've created my EDMX model from the database, but I've noticed where you would use _ctx.Set to template against the code-first table per class pattern, the Set() method isn't available on the entities created by the generated .edmx file. I would have thought that EF would be able to flip between the 2 types quite easily. Do I have to re-write my repository class just so it will work with EDMX models?

Answer 1

By default for model first and database first approaches VS2010 generates ObjectContext based context and EntityObject based entities. This changed in VS2012 where by default POCO entities and DbContext based context will be generated. CodeFirst uses POCO entities and DbContext based context which is in line with VS2012 but not VS2010. However even with VS2010 you can generate DbContext and POCO entities. First, right click on the designer surface and in the properties change code generation strategy from Default to None. Then right click on your project and "Add a new Item". Click "Online" to the left. You can type DbContext in the search dialog. Select "EF 4.x DbContext Generator for C#". This will add T4 templates to your project that will generate DbContext based context and POCO entities from your edmx file.