Entity Framework 6 Using Lambda GroupBy on a joined table

Question

I have two tables, Drivers and ViewDrivers that I have joined together using the following lambda expression in Entity Framework 6.

var inAppDriverList = context.ViewDrivers
.Select(dv => new { dv.TerminalCode, dv.EmployeeId })
.Join(
          context.Drivers,
          d => d.EmployeeId,
          dv => dv.EmployeeId,
          (d, dv) => new { d, dv }
      ))
.OrderBy(dv => dv.TerminalCode)
.GroupBy(dv => dv.TerminalCode
.ToList();

It does give me the data that I am expecting to get, but I when I try to Sort and Group the list by the TerminalCode using GroupBy and OrderBy , I cannot get it to work correctly. I have tried everything I can think of, with no luck.

I am only having this issue when I am trying to sort a joined table so I am guessing there is something small that I am missing. I would greatly appreciate any help in getting those statements to Group and Sort by the TerminalCode field.

Answer 1

The result of your Join will be a sequence of the anonymous class that you created with

(d, dv) => new { d, dv }

So when you try to order and group you need a lambda like

x => x.dv.TerminalCode

That or specify the values of dv in the anonymous class

(d, dv) => new { d, dv.TerminalCode, dv.EmployeeId  }

With that option you then wouldn't need the Select before the Join . Additionally if you don't need all the columns in Drivers you can also specify them as well thus reducing the amount of data that your query has to return.