Question

Definition of my Class

    Public Class ProcessAlert
       Public LoanNumber As String
       Public EmailAddress As String
       Public AlertType As String
       Public AlertMethodID As Byte
    End Class

A generic list that is representative of data returned from DB

     Dim a As New List(Of ProcessAlert)

     a.Add(New ProcessAlert("0000112367", "[e-mail]", "Alert", 2))
     a.Add(New ProcessAlert("0000112367", "[e-mail]", "Document", 2))
     a.Add(New ProcessAlert("0000112367", "[e-mail]", "Note", 2))
     a.Add(New ProcessAlert("0000112367", "[e-mail]", "Alert", 1))
     a.Add(New ProcessAlert("0000112367", "[e-mail]", "Document", 1))
     a.Add(New ProcessAlert("0000112367", "[e-mail]", "Note", 1))

     Return a

I managed this LINQ statement that will group by LoanNumber and EmailAddress but I can’t get the AlertType to show up as a concatenated field of all 3 values

     Dim res = Alerts.GroupBy(Function(g) New With {Key .A = g.LoanNumber, Key .B = g.EmailAddress}) 

This code will give me a grouping by EmailAddress and the values I need of:
“[e-mail]”, “Alert, Document, Note”
“[e-mail]”, “Alert, Document, Note”

    Dim res = Alerts.GroupBy(Function(i) i.EmailAddress).Select(Function(g) New KeyValuePair(Of String, String)(g.Key, String.Join(",", g.Select(Function(x) x.AlertType).ToArray())))

But I cannot seem to get the statement give me a return that looks like this:

    "0000112367","[e-mail]", "Alert, Document, Note"
    "0000112367","[e-mail]", "Alert, Document, Note"

How do I get 2 fields to group and then concatenate the values of AlertType into a single field???

Thanks in advance

Answer 1

Are you looking for something like this:

From _a In a
Group _a.AlertType By _a.LoanNumber, _a.EmailAddress Into Group
Select New With
{
    .LoanNumber = LoanNumber,
    .EmailAddress = EmailAddress,
    .AlertTypes = String.Join(", ", Group.ToArray())
}