Multidimensional Arrays using Dictionaries - vb.net

Question

I am trying to make a multidimensional associative array. I want it so I can have something like:
someVar(date)(hour)(category) = mssql query
I am using the following to try and prepare but am having trouble adding data to the array.
Dim test As New Dictionary(Of Integer, Dictionary(Of String, String))
Dim test2 As New Dictionary(Of String, String)
Any help is greatly appreciated.
-----EDIT:
Here is what I am using, it works as desired. Doe ayone see why this would be a bad way to do it?
Dim test As New Dictionary(Of Integer, Dictionary(Of String, String))
Dim SomeNum As Integer = 0
Dim someStr As String = "This is a string: "
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
While SomeNum < 100
Dim someNum2 As Integer = 0
Dim test2 As New Dictionary(Of String, String)
While someNum2 < 100
test2.Add(CType(someNum2, String), someStr & CType(someNum2, String))
someNum2 += 1
End While
test.Add(SomeNum, test2)
SomeNum += 1
End While
For Each kvp As KeyValuePair(Of Integer, Dictionary(Of String, String)) In test
Dim ccc As String = ""
Dim ddd As String = ""
Dim v1 As String = CType(kvp.Key, String)
Dim v2 As Dictionary(Of String, String) = kvp.Value
lblOne.Items.Add("Key: " & v1)
For Each kvp2 As KeyValuePair(Of String, String) In v2
Dim v3 As String = kvp2.Key
Dim v4 As String = kvp2.Value
lblTwo.Items.Add("SubKey: " & v3 & " Value: " & v4)
lblOne.Items.Add("")
Next
lblOne.Items.Add(v1 & " End--------------")
lblTwo.Items.Add(v1 & " End--------------")
Next
End Sub

Answer 1

Create a class with properties "Date", "HourlySales", "Category".
Public Class Sales
Public Property SalesDate() As Date
Public Property HourlySales() As Decimal
Public Property Category() As String
Public Sub New()
End Sub
Public Sub New(vSalesDate As Date, vHourlySales As Decimal, vCategory As String)
SalesDate = vSalesDate
HourlySales = vHourlySales
Category = vCategory
End Sub
End Class
Create a list of objects of type Sales
Shared Function GetSales() As List(Of Sales)
Dim SalesList As New List(Of Sales)
Using connection As New SqlConnection(YourConnectionString)
Dim cmd As SqlCommand = New SqlCommand("SelectSalesList", connection)
cmd.CommandType = CommandType.StoredProcedure
cmd.Connection.Open()
Dim reader As SqlDataReader = cmd.ExecuteReader()
While reader.Read
SalesList.Add(New Sales(reader("SalesDate"), reader("HourlySales"), reader("Category")))
End While
End Using
Return SalesList
End Function
You can call the GetSales() function to return a list of Sales.

Answer 2

Look into Entity Framework it makes objects out of your database.
MSDN EF
For a custom array, you may find a Tuple useful.

Answer 3

A dictionary of dictionary of dictionaries is a maintenance nightmare, to query and debug.
I suggest to have a composite key instead, so instead of doing 3 lookups you would just do one for a string of date+hour+category. For example, date=Monday, hour=9PM, category=Apples, your key is Monday:9PM:Apples (I picked colon as parts separator, but you can choose a different character).