Question

am stuck with this linq query, all i need is to optimize the last price calculation, cause i get about a 1000 article, & a lot of sales so its getting slow …

var result = from article in db.Entities.Articles 
select new{
     article.ID_ART,
     article.Designation,
     article.BuyPrice,
     article.SellPrice,
     LastPrice = (from sale in article.Sales where sale.Date == article.Sales.Max(X => X.Date) select sale.Price).FirstOrDefault()==0?
     article.BuyPrice: (from sale in article.Sales where sale.Date == article.Sales.Max(X => X.Date) select sale.Price).FirstOrDefault()
     }

Answer 1

var result = from article in db.Entities.Articles 
    let lastPrice = (from sale in article.Sales 
                     orderby sale.Date descending 
                     select sale.Price).FirstOrDefault()
    select new
    {
        article.ID_ART,
        article.Designation,
        article.BuyPrice,
        article.SellPrice,
        LastPrice = lastPrice ==0 ? article.BuyPrice : lastPrice
    }