Find unique values in list collection and perform further processing

Question

User1909155429 posted

For Each p As freelancerproduct In pr

 parameters.Add(New String() {"amount", p.Rate.ToString()})

 parameters.Add(New String() {"email", p.SellerPaypalAccountId})


counter += 1


Next


The problem here is that  SellerPaypalAccountId  property has to be a unique element before  added to the parameters list. As a consequence each p element in the list needs to be checked for repetitive  p.SellerPaypalAccountId property.

if more than one p.SellerPaypalAccountId value in the list  then each corresponding  p.Rate property value needs to be added together before the  p.SellerPaypalAccountId and p.Rate elements are added to parameters. shown below. 

Answer 1

User-417640953 posted

Hello,

I overviewed your description and code you provided. And I see that you want get Rate together which has same SellerPaypalAccountId .

later, add the list to parameters list.

For the issue, I suggest you use linq query to complete the efficacy. Please try below code:

Dim pr2 = (From s In From c In prGroup c By c.SellerPaypalAccountIdNew With { _
         Key .Rate = s.Sum(Function(c) CSng(c.Rate)), _
         Key .SellerPaypalAccountId = s.Key _
}).ToList()

Dim parameters As New List(Of String())()

For Each p As var In pr2
         parameters.Add(New String() {"amount", p.Rate.ToString()})
         parameters.Add(New String() {"email", p.SellerPaypalAccountId.ToString()})
         
Next

Hope it helps, thanks.

 

Best Regards!

Answer 2

User1909155429 posted

That is a very interesting method!

Although i am working with pure vb code in class file. With data stored as a Product object in a List collection.

 

Thanks

Answer 3

User1909155429 posted

i am getting an error message on c stating '(' is missing ?

Also how is the query reference the product object amount and email values using c as an argument  from list collection ?

 

pr is the reference variable for product object.

 

Thanks

 

Answer 4

User-417640953 posted

Hello peterthegreat,

I'm glad to you feedback. For the above Linq query , I was use C#.

Below demo is pure VB code, please try it.

Product.vb

Public Class Product
    Public Sub New()
    End Sub
    Public Sub New(rate As Single, sellPAcc As String)
        Me.Rate = rate
        Me.SellerPaypalAccountId = sellPAcc
    End Sub
    Public Property Rate() As Decimal
        Get
            Return m_Rate
        End Get
        Set(value As Decimal)
            m_Rate = value
        End Set
    End Property
    Private m_Rate As Decimal
 
    Public Property SellerPaypalAccountId() As String
        Get
            Return m_SellerPaypalAccountId
        End Get
        Set(value As String)
            m_SellerPaypalAccountId = Value
        End Set
    End Property
    Private m_SellerPaypalAccountId As String
End Class

aspx.vb

 Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        

        Dim products As New List(Of Product)()
        products.AddRange(New Product() {New Product(3.45, "accountid1"), New Product(2.45, "accountid1"), New Product(5.15, "accountid2"), New Product(6.25, "accountid2"), New Product(1.45, "accountid3"), New Product(0.95, "accountid3")})
         
        Dim pr = From p In products Group p.Rate By Key = p.SellerPaypalAccountId Into Group = Group _
                  Select New With {.SellerPaypalAccountId = Key, .Rate = Group.Sum()}
        
        Dim parameters As New List(Of String())()

        For Each p In pr
            Response.Write(Convert.ToString(p.SellerPaypalAccountId) & ":" & Convert.ToString(p.Rate) & "<br/>")
            parameters.Add(New String() {"amount", p.Rate.ToString()})
            parameters.Add(New String() {"email", p.SellerPaypalAccountId})
        Next



    End Sub

I test it runs fine, thanks.

 

Best Regards!

Answer 5

User1909155429 posted

I found this method although it corresponds to database. Is this not a alternative workable solution for the aforementioned task ?

  'Dim averageCustomersByCity = From cust In db.Customers
        '                     Group By cust.City
        '                     Into Sum(cust.Orders.Count)
        '                     Order By Average