Group by two properties as one in Linq

c#, linq

Solution

This should work:

var query = from b in Bookings
    group b by new
    {
        b.Group, 
        b.Type, 
        b.Status,
        InvType = String.Format({0}-{1},b.InvoicingFrequency, b.InvoicingLevel)
    } into bookingGroup
    select new BookingSummaryLine()
    {
        Group = bookingGroup.Key.UserGroup,
        Type = bookingGroup.Key.UserGroup,
        Status = bookingGroup.Key.FinancialStatus,
        InvType = bookingGroup.Key.InvType
    };

Problem

I have the following class ``` public class Booking { public string Group { get; set; } public BookingType Type { get; set; } public BookingStatus Status { get; set; } public InvoiceFreq { get; set; } public InvoiceLevel { get; set; } } ``` That I'd need to group them by all properties in Linq so that the last two properties form one new field in the grouped result. Like this: ``` Group Type Status InvoiceType ------------------------------------------- Group1 Online New Daily-Single Group2 Phone Accepted Daily-Single Group3 Store Accepted Weekly-Single Group3 Store Accepted Weekly-Bulk ``` Here the InvoiceFreq will be Daily / Weekly and the InvoiceLevel = Single or Bulk. The query I have so far is this: ``` var query = from b in Bookings group b by new { b.Group, b.Type, b.Status, b.InvoicingFrequency, b.InvoicingLevel } into bookingGroup select new BookingSummaryLine() { Group = bookingGroup.Key.UserGroup, Type = bookingGroup.Key.UserGroup, Status = bookingGroup.Key.FinancialStatus, InvType = String.Format({0}-{1},bookingGroup.Key.InvoicingFrequency, bookingGroup.Key.InvoicingLevel }; ``` This of course does not give the desired result as the two properties are in the anonymous type separately. Is there any way to achieve this in Linq?

Original source