Question

been searching for a quick example of sorting a IQueryable (Using Linq To SQL) using a Aggregate value.

I basically need to calculate a few derived values (Percentage difference between two values etc) and sort the results by this.

i.e.

return rows.OrderBy(Function(s) CalcValue(s.Visitors, s.Clicks))

I want to call an external function to calculate the Aggregate. Should this implement IComparer? or IComparable?

thanks

[EDIT] Have tried to use:

Public Class SortByCPC : Implements IComparer(Of Statistic)  Public Function Compare(ByVal x As Statistic, ByVal y As Statistic) As Integer Implements System.Collections.Generic.IComparer(Of Statistic).Compare     Dim xCPC = x.Earnings / x.Clicks     Dim yCPC = y.Earnings / y.Clicks     Return yCPC - xCPC End Function  End Class 

LINQ to SQL doesn’t like me using IComparer

Answer 1

My solution:

Dim stats = rows.OrderBy(Function(s) If(s.Visitors > 0, s.Clicks / s.Visitors, 0)) 

This also catches any divide by zero exceptions