How to retrieve object's information?

W

Widunder

Newcomer
Joined
Aug 3, 2010
Messages
10
Hello everyone,
I have three different tables. Customer, Product and Orderline. Now, I want to find how to retrieve the information from a product object in order to insert that data into the orderline. My product object has pName as a key, and imagePath and pPrice as attributes. But all I want - is to get the price, to be returned as a decimal value.
This is what I've done so far and it's not working:
Code: 
Public Function priceLookUp(ByVal pName As String)
        Dim SQL As String = "select pPrice from product where pName = '" & pName & "'"
        Dim dtProducts As DataTable = myData.getData(SQL)

        Dim colProducts As Collection = New Collection
        Dim objProduct As Product
        Dim drRow As DataRow

        For Each drRow In dtProducts.Rows
            objProduct = New Product 'empty object being created?

            objProduct.ProductPrice = drRow.Item("pPrice")

            If colProducts.Contains(pName) = True Then
                objProduct = colProducts("ProductName")
            Else

            End If
        Next
        Return colProducts("pPrice") 'this line is the one that I have problem with
    End Function
I'm having the problem with the last line. I'm getting the correct product name - finding it's key, but how do I get the price of that product?
I've tried to modify that line heaps of times now, and I still just cant figure it out.
I've tried drRow.Item("pPrice") - that didn't give me any errors, though at the same time, it didn't add nothing to the orderline table. Because I was guessing that an empty object of product is being created. But how to avoid this?
Please help.
Thank you.
Widunder.
 
You might want to switch from using the Collection class to a more modern replacement such as List(Of ...) e.g.
Visual Basic: 
  Dim colProducts As List(Of Product) = New List(Of Product)

then in the final line you could do something like
Visual Basic: 
colProducts("pPrice").ProductPrice

However if you are just returning a single price from a single product then you can probably simplify the code considerably as there is no need for a collection of products to return a single product price. e.g.

Visual Basic: 
Public Function priceLookUp(ByVal pName As String) as Decimal
Dim SQL As String = "select pPrice from product where pName = '" & pName & "'"
Dim dtProducts As DataTable = myData.getData(SQL)
     
Dim drRow As DataRow = dtProducts.Rows(0)

Return DirectCast( drRow("pPrice"), Decimal)
End Function

That might not be perfect as I don't have VB on this PC at the moment but it should get you started.
 
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