Question

I have a table with products

Id  |  Name      |  Order
1   | product 1  |    5
1   | product 1  |    9
1   | product 1  |    2 
2   | product 2  |    0
3   | product 3  |    1

I need to return just the product with the max order number:

Id  |  Name      |  Order

1   | product 1  |    9
2   | product 2  |    0 
3   | product 3  |    1

tried this but it’s not working:

var items = (from i in db.products
                 group i by new
                 {
                     i.Id,
                     i.Name,
                     i.Order
                 } into g

                 select new
                 {
                     g.Key.Id,
                     g.Key.Name,
                     Order = g.Where(d => d.Order == g.Max(xx => xx.Order )).First().Order     })

but it stills return all the 5 results.
thank you

Answer 1

Change

             group i by new
             {
                 i.Id,
                 i.Name,
                 i.Order
             } into g

into

             group i by new
             {
                 i.Id,
                 i.Name,
             } into g

I think I would also rewrite the the last expression to

Order = g.OrderByDescending(xx => xx.Order).First().Order

Mostly because I think it is easier to read, but the generated SQL might be more efficient too. But this is just a matter of taste and any performance difference can be verified with SQL Profiler.