Create a new anonymous type list to union onto existing anonymous type list

Question

I have a list of anonymous types that I get from my database:

var takenChannels = (from b in bq.GetStuff(db)
                     where b.RecordType == "H" && b.TourStartDateTime.Date == date
                     select new { Start = b.TourStartDateTime, End = b.TourEndDateTime, Channel = b.RadioChannel, TourArea = b.TourArea }).ToList();

Then I use this list info to do some stuff in a foreach loop. I want to add to this list a new anonymous item for when I come back round in the loop.

Something like:

takenChannels.Union{new[] { new{Start = DateTime.Now, End = DateTime.Now.AddDays(1), Channel = 25, TourArea = "Area" }});

Obviously this doesn't work. How do I do it?

Edit 1:

takenChannels.Add(new { Start = s, End = e, Channel = channel, TourArea = booking.TourArea });

This is the closest I've got so far (Thanks to Daniel)... but the error I get is:

Error 6 Argument 1: cannot convert from 'AnonymousType#2' to 'AnonymousType#1'

Answer 1

This answer might be a bit late, but since this is the question I found when Googling for the same problem, I think I should complete it with a working answer.

There is no problem to Union multiple times over anonymous types. It is important that all properties are declared in all instances and that they have the same data type. if not, you get the error above.

• In your specific case, does the database perhaps return TourStartDateTime or TourEndDateTime as DateTime??
• Is RadioChannel an int from the database or perhaps an int? or string?
• Is TourArea a string in the database?

Just make sure the data types match and you should be fine. Below is a working snippet of code I use in my own program:

var regions = (
    new[] { new { Id = "-1", Name = "---", Pattern = (string)null } }
  ).Union(
    from x in db.Userlists where x.ListType == 2 select new { Id = x.UserlistID.ToString(), Name = x.Name, Pattern = (string)null }
  ).Union(
    from x in db.Lookups where x.Category == "Stock" select new { Id = x.Key, Name = x.Key, Pattern = x.Value }
  ).ToArray();

Answer 2

You can simply Add to the list:

takenChannels.Add(new { Start = ... });