Question

I’m using EF 4.2 and originally I had rolled my own repository classes for each entity set. As I investigated further I realised that DbContext and IDbSet implemented the unit of work and repository pattern I required.

This works great, but I would also like some “helper” methods to return particular entities using commonly requested properties, other than the primary key.

For example to select an employee by email and account status rather than the Id primary key. My original user repository had an overload for this.

My question is where should I add this helper method? I see myself as having a few options:

1. Add a domain logic service type class with this method which uses dbContext, and is consumed by other domain logic classes and methods.
2. Extend the DbContext class to have an additional method.
3. Replace the IDbSet with a custom repository.
4. Wrap the dbContext in additional Repository classes for each entity set, and add a method to the user specific one.

There seem to be pros and cons for each, but I’m leaning more towards 1 or 2. Any thoughts?

Answer 1

You can use custom extension method and reuse it:

public static IQueryable<Employee> Find(this IQueryable<Employee> query, 
                                        string email, string status) 
{
    return query.Where(e => e.Email == email && e.Status == status);
}

Now you will use it simply like:

var employee = context.Employees.Find(email, status).FirstOrDefault();