LINQ to Entities - Rounding to the nearest dollar, nearest half-dollar, or not at all?

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.

Up vote 2 down vote favorite share g+ share fb share tw.

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 => 133.15 ID 2: 133.15 => 133.158 public IQueryable 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... c# linq entity-framework linq-to-entities link|improve this question edited 3.159 at 17:54Aducci4,8741414 asked 3.159 at 16:47Greg Snider134.

The way you're looking to have them rounded here. But yes - Math.Round() doesn't do this out of the box for you. – 48klocs Feb 16 at 16:56 I don't believe you can create extension methods within a LINQ query.

The CustomPrice and Retail properties are decimals. Yeah, I wish .Round() would have some more options for me. – Greg Snider Feb 16 at 17:17 You can do whatever you want inside of a Linq query; if you're talking Linq to Entities/Linq to SQL then yes, you're quite a bit more restricted in what you can do inside of the query.

If you reify that anonymous type into a defined type, you could fluently perform the rounding after the data's been retrieved. – 48klocs Feb 16 at 17:27 "If you reify that anonymous type into a defined type, you could fluently perform the rounding after the data's been retrieved" - How would I go about doing this? I can create a defined type for it.

How would I perform the rounding after the data has been received? I would like to have this contained within this one function because a lot of different areas and websites will be using it. – Greg Snider Feb 16 at 17:48.

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 Price + 1 - cents)) select new { FinalPrice = roundingId == 0? Ps. Price : (roundingId == 1?

UpToDollar : upToHalfDollar) }.

Perfect! Thank you very much for this. – Greg Snider Feb 16 at 18:10 Nice, that's an elegant solution.

– Grant H. Feb 16 at 18:20.

You can do it all inline if you want, but honestly that seems like it'd be hard to read. Try this: int roundingId = 0; //0 = no rounding. 1 = dollar rounding.

2 = half-dollar rounding. Var prices = from ps in ObjectContext. Products select new { FinalPrice = GetPrice((ps.

IsCustomPrice? Ps. CustomPrice : ps.

Retail), roundingId), } private double GetPrice(double price, int roundingOption) { switch (roundingOption) { case 0: //Do stuff break; case 1: //Do stuff break; case 2: //Do stuff break; } }.

Unfortunately you cannot call a method from within LINQ. I tried your example and received: LINQ to Entities does not recognize the method 'System. Decimal GetPrice(System.

Decimal, Int32)' method, and this method cannot be translated into a store expression. – Greg Snider Feb 16 at 17:15 1 Ah, you CAN call a method from within LINQ, but not LINQ to Entities, or LINQ to SQL, etc. – Grant H. Feb 16 at 17:17 I will update my question to add that information.

– Greg Snider Feb 16 at 17:18 In that case, I'd recommend you just perform the operation after the query has returned. I don't see another option without simply nesting the inline bools as you have done above. – Grant H.

Feb 16 at 17:19 Nesting inline bools would work for me (I don't mind if it is a little messy), but combining that with Rounding to Half-dollar is giving me much trouble... – Greg Snider Feb 16 at 17:20.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.