Question

I have a method in my repository to retrieve All records for Items

public IQueryable<Item> GetAll()
        {
            //The following causes a circular reference if you attempt to serialize it via an API call.
            IQueryable<Item> items = context.Items.Include(c => c.UserProfile).Include(c => c.UserProfile1).AsQueryable();
            return items;
        }

This causes issues with Kendo Grid and serialization because of how I am including the foreign tables User Profile twice to be able to get the full name of the user whom created and modified the Item record.

Instead of Include(c => c.UserProfile) is there a way to only include the UserProfile.FullName column?

Today I am handling this in my ViewModel and creating a new subclass (this example is for Locations, not Items):

public class LocationsListViewModel
    {
        public IEnumerable<LocationsGrid> Locations { get; set; }
        public IEnumerable<Facility> Facilities { get; set; }
        public IEnumerable<string> AreaOptions { get; set; }
        public int LocationCount { get; set; }

        public class LocationsGrid
        {
            public int Id { get; set; }
            public string DisplayLocation { get; set; }
            public string Area { get; set; }
            public string Zone { get; set; }
            public string Aisle { get; set; }
            public string Bay { get; set; }
            public string Level { get; set; }
            public string Position { get; set; }
            public string Barcode { get; set; }

        }
    }

and then having to populate that in my Tasks or App Services layer (sits between controller and repository) like this:

viewModel.Locations = from l in locations.ToList()
select new LocationsListViewModel.LocationsGrid
{
   Id = l.Id,
   DisplayLocation = l.DisplayLocation,
   Area = l.Area,
   Zone = l.Zone,
   Aisle = l.Aisle,
   Bay = l.Bay,
   Level = l.Level,
   Position = l.Position,
   Barcode = l.BarcodeValue
};

This seems like a lot of extra code and maintenance for each entity going forward. I’m sure there is a more efficient way to do this.

Answer 1

I typically use a Data-Transfer Object (basically just a class that has the exact data you’re looking for, then returning objects of that type from your data-access method.

    public IQueryable<ItemSummary> GetAll()
    {
        IQueryable<ItemSummary> items = context.Items
            .Select(c => new ItemSummary {
                   FirstProfileName = c.UserProfile.FullName,
                   SecondProfileName = c.UserProfile1.FullName,
                   ScalarProp1 = c.ScalarProp1,
                   ...
                })
            .AsQueryable();
        return items;
    }

I’m not sure if that will work the way you want it to, since I’m not familiar with Kendo Grid and such, but it may be useful.