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How can I add an extra object to the results of a LINQ query?

I have the following code that needs to add an additional object after the results have been retrieved from the database. Any ideas on how I can go about doing this?

   public IEnumerable<ProdPriceDisplay> GetShopProductsPrices()
{

    //ProdPriceDisplay ProdPrice = new ProdPriceDisplay();
    var Products = from shop in db.SHOPs
                   select new ProdPriceDisplay
                   {
                       ProdPrice = shop.S_NAME + " - £" + shop.S_PRICE
                   };

    // *** Want to add something like this:-

    //  Products.Add new ProdPriceDisplay { ProdPrice = "some additional text"; }

    return Products;
}
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2 answers


Use Enumerable.Concat

:

public IEnumerable<ProdPriceDisplay> GetShopProductsPrices()
{
    var products = from shop in db.SHOPs
                   select new ProdPriceDisplay
                   {
                       ProdPrice = shop.S_NAME + " - £" + shop.S_PRICE
                   };

    return products.AsEnumerable()
                   .Concat(new [] { new ProdPriceDisplay 
                           { ProdPrice = "some additional text"; });
}

The advantage of doing this conversion on a list is that the results are still streamed, so you don't get a complete copy of the data.



EDIT: you can use instead of an array if you like - but not much use.Enumerable.Repeat

(new ProdPriceDisplay { ... }, 1)

EDIT: I've added a call AsEnumerable()

that basically says "At this point we don't want to do the rest of the operations on the database - make them local."

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It might be a solution;



var productsAsList = Products.ToList();
productsAsList.Add(new ProdPriceDisplay { ProdPrice = "some additional text"; });

return productsAsList; // As your return type is IEnumarable, that won't be a problem;
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