Perform calculation inside select statement in LINQ

Question

I have a situation where i have to calculate percentage of two values for example

IEnumerable result = 
    from r in renewalLists
    gro         


        

Answer 1

Altough I do not understand why one would devide a number by itself just to multiply it by 100 - I believe the thing you're looking for is called let. Now, I have not tested this but it should work somehow similar to this:

IEnumerable result = 
    from r in renewalLists
    group r by r.CityID into grpCity
    let potentialRenewalCount = (from g in grpCity where g.CityID == grpCity.Key select g.PotentialRenewalCount).Sum()
    let desiredCalculation = (PotentialRenewalCount/PotentialRenewalCount)*100
    select new RenewalModel
    {
    CityID = grpCity.Key,
    City = (from g in grpCity where g.CityID == grpCity.Key select g.City).First().Trim(),
    PotentialRenewalCount = potentialRenewalCount,
    PotentialRenewalSQRT = (from g in grpCity where g.CityID == grpCity.Key select g.PotentialRenewalSQRT).Sum(),
    DesiredCalucation =   desiredCalculation,
    RENEWALCOUNT = (from g in grpCity where g.CityID == grpCity.Key select g.RENEWALCOUNT).Sum(),
    RENEWALSQRT = (from g in grpCity where g.CityID == grpCity.Key select g.RENEWALSQRT).Sum()
};

And also think about the case when the SUM is 0 since this would lead to a division by zero!