Question

I need to round FinalPrice the following ways based on an identifier:

• 0 = Not at all
• 1 = Up to the next Dollar
• 2 = Up to the next Half-dollar

Example of the expected rounding:

• ID 0: 133.15 => 133.15
• ID 1: 133.15 => 134.00
• ID 2: 133.15 => 133.50

 public IQueryable<MyObj> GetPrices()
    {
        int roundingId = 0; //0 = no rounding. 1 = dollar rounding. 2 = half-dollar rounding.

        var prices = from ps in ObjectContext.Products
        select new MyObj
        {
             FinalPrice = (ps.IsCustomPrice ? ps.CustomPrice : ps.Retail),
        }

        return prices;
    }

I wish I could use a custom function to do this rounding in LINQ to Entities…

Answer 1

This will work for you. You can clean it up for your own use, but basically you are just using the % modulo operator to get the cents and the ? : ternary operator to select the correct value

var prices = from ps in ObjectContext.Products
             let cents = ps.Price % 1
             let upToDollar = cents > 0 ? (ps.Price + 1 - cents) : ps.Price
             let upToHalfDollar = cents == 0 ? ps.Price : (cents < 0.5 ? (ps.Price + 0.5 - cents) : (ps.Price + 1 - cents))
             select new
             {
               FinalPrice = roundingId == 0 ? ps.Price : (roundingId == 1 ? upToDollar : upToHalfDollar)
             };