按组列表<项目> [英] Group By List<Item>
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问题描述
我有这个类:
I have this class:
public class Item
{
public virtual int32 Id { get; set; }
public virtual Previa Previa { get; set; }
public virtual Product Product { get; set; }
public virtual Int32 Quantity { get; set; }
public virtual Decimal Price { get; set; }
public virtual Decimal Total { get; set; }
}
现在我需要查询来查找数据库中的每个项目,组按产品计算,数量和总计之和。
为了找到每件物品,我使用:
And now i need to a query to find every Items in database, group by Products, with the sum of Quantity and Total. For find every Items, i use:
public List<Item> FindItem(int IdProduct = 0)
{
var retorno = (from c in Session.Query<Item>()
select c);
if (IdProduto > 0)
retorno = retorno.Where(x => x.Product.Id == IdProduct)
return retorno.ToList<Item>();
}
但我不知道如何分组这些项目。有人可以帮我吗?
But I don't know how to group these items. Could someone please help me?
推荐答案
你的问题很不清楚,但它听起来像需要一个查询,例如:
Your question is far from clear, but it sounds like you want a query such as:
var query = from item in Session.Query<Item>()
group item by item.Product into g
select new {
Product = g.Key,
Quantity = g.Sum(item => item.Quantity),
Total = g.Sum(item => item.Total)
};
然后你如何传递回来是另一回事 - 几乎可以肯定不想要列表< Item>
尽管...
How you then pass that back is a different matter - you almost certainly don't want a List<Item>
though...
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