Using DbQuery in linq join -> Entity Framework Core

Question

I have a query ( DeliveryDates ) and a dbset ( Products ) in EF Core and I want to join them in linq.

I tried this:

var list = await (from d in _financeContext.DeliveryDates
                  join p in _financeContext.Products on d.ProductId equals p.ProductId
                  select new
                          {
                          }).ToListAsync();

But I get this error:

Could not find an implementation of the query pattern for source type 'DbQuery'. 'Join' not found. (CS1936)

Is there anyway to join a dbquery and a dbset in linq ?

Answer 1

join is a Linq function. It looks like you don't add a using to System.Linq;

using System.Linq;

var list = await (from d in _financeContext.DeliveryDates
              join p in _financeContext.Products on d.ProductId equals p.ProductId
              select new
                      {
                      }).ToListAsync();

Answer 2

var firstlist=_financeContext.DeliveryDates.tolist();

var list = await (from d in firstlist
                  join p in _financeContext.Products on d.ProductId equals p.ProductId
                  select new
                          {
                          }).ToListAsync();