Try using this in LinqPad, and subbing out for your database entity it should get you closer. 

	Public Sub grouper2()
		Dim numbers = New Integer() {1,1,2,2,2,3}
	
		Dim numberGroups = From w In numbers _
						Group w By Key = w Into Group _
						Select Number = Key, numbersCount = Group.Count()
	
		'linqpad specific output
		'numberGroups.Dump()
		
		For Each g In numberGroups
			Console.WriteLine("Numbers that match '{0}':", g.Number)
				Console.WriteLine(g.numbersCount)        
		Next
	
	End Sub


I'm trying to use a LINQ query to determine how many of each particular object type I have and record those values into an anonymous type.

Let's say I have some data that looks like this (there are really objects exposing this property, but it'll work the same)

    GroupId
    1
    1
    2
    2
    2
    3

I know how to format my query in SQL.  It would be something like this:



    SELECT grp = GroupId, cnt = COUNT(*)
    FROM myTable
    GROUP BY GroupId

In this case the output would be something like [this SQL Fiddle][1]:

    GroupID  Count
    1        2
    2        3
    3        1

How can I do the same thing with LINQ in vb.net



    Dim groupCounts = From person In data
                      Group By person.GroupId
                      Select new {group = person.GroupId, count = count(*)}

That's not quite right, but I think it's close.

Also, not knowing much about anonymous types, can I actually declare `groupCounts` ahead of time that it will be an enumeration of items which each have a group and count property?

[1]: http://sqlfiddle.com/#!9/ef3427/1