数据读取器格式化输出

我正在使用以下函数生成连接到选定数据库的用户列表。对于多个相同的结果,如何将此更改为一行? 例如:“sa(3)-mycomputer”而不是将“sa-mycomputer”列出三次?

Function ConnectedUsers(ByVal SelectedDatabase As String, ByVal SelectedInstance As String)
    Dim myCommand As SqlCommand
    Dim dr As SqlDataReader
    Dim mystring As String = String.Empty
    Try
        Dim myConn As New SqlConnection(ConnectionString)
        myConn.Open()
        myCommand = New SqlCommand("select loginame,hostname from sysprocesses where db_name(dbid) = '" & SelectedDatabase & ";", myConn)
        dr = myCommand.ExecuteReader()
        While dr.Read()
                        mystring += GetFullName(dr(0).ToString().Trim()) & " - " & dr(1).Trim() & vbCrLf
        End While
        dr.Close()
        myConn.Close()
    Catch e As Exception
        MessageBox.Show(e.Message)
    End Try
    Return mystring
End Function

谢谢。