EntityFramework do Paging on a query with a join

Question

I have a query with a left join in it:

   var query = (from v in context.Vehicles

                //left join vehicleAttributes
                join va in context.VehicleAttributes on v.VehicleId equals va.VehicleId into vAttributes
                from vehicleAttributes in vAttributes.DefaultIfEmpty()

                where v.FleetId == fleetId

                select new { v, vehicleAttributes });

And now I need to do a paging on it.

this works but gets all rows, so much more than i actually need

query.ToList().Select(x => x.v).Distinct().Skip(10 * (page - 1)).Take(10).ToList();

this is what I tried instead but now I don't have the joint values

query.Select(x => x.v).Distinct().ToList().Skip(10 * (page - 1)).Take(10).ToList();

Answer 1

The ToList() triggers the call to the database so you need to only do this after you apply the Skip and Take. You'll need an OrderBy clause as well.

You should be able to do something like this:

var data = (from v in context.Vehicles
         join va in context.VehicleAttributes on v.VehicleId equals va.VehicleId into vAttributes
         from vehicleAttributes in vAttributes.DefaultIfEmpty()
         where v.FleetId == fleetId
         select new { v, vehicleAttributes })
         .OrderBy(p => p.v.FleetId)
         .Skip(10 * (page - 1))
         .Take(10)
         .ToList();