Question

Afternoon,

I am trying to return a list of products from my SQL Server 2008 R2 database but I only want to return the results with the latest date.

However the code below seems to return all items, even the ones with an older date. How do I go about getting my results with just the latest date.

var query = (from a in dc.aboProducts
             join t in dc.twProducts on a.sku equals t.sku
             join lp in dc.LowestPrices on a.asin equals lp.productAsin
             select new GetLowestPrices
             {
             productAsin = lp.productAsin,
             sku = t.sku,
             title = t.title,
             twprice = Convert.ToString(t.twPrice),
             lowprice = Convert.ToString(lp.price),
             amzprice = Convert.ToString(lp.tweAmzPrice),
             lastupdated = Convert.ToDateTime(lp.priceDate)
             }).Distinct().OrderBy(ti => ti.title);
return query.ToList();

Answer 1

Try something like this:

var query =
    from a in dc.aboProducts
    join t in dc.twProducts on a.sku equals t.sku
    join lp in dc.LowestPrices on a.asin equals lp.productAsin
    select new GetLowestPrices
    {
        productAsin = lp.productAsin,
        sku = t.sku,
        title = t.title,
        twprice = Convert.ToString(t.twPrice),
        lowprice = Convert.ToString(lp.price),
        amzprice = Convert.ToString(lp.tweAmzPrice),
        lastupdated = Convert.ToDateTime(lp.priceDate)
    };

var lookup =
    query
        .ToLookup(x => x.sku)
        .Select(x => x.OrderByDescending(y => y.lastupdated).First())
        .OrderBy(x => x.title);

return lookup.ToList();