C# linq查询中的orderby计数（其他_表）

如标题中所述，我想使用另一个表的列

orderby

结果表

var products = (from p in db.Products
               join o in db.OrderDetails on p.ProductID equals o.ProductID
               orderby count(o.Quantity) <-- want to do something like this
               select p).Distinct().Take(8).ToList();

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我得到了想要的结果。但是我如何使用LINQ呢？

只要创建一个字典，其中键是产品，值是计算数量，然后执行查询

或者这样做：

var product = p in resultOfTheJoin
        let count = resultOfTheJoin.Quantity.Count()
        orderby count
        select p;

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如果我明白的话，你需要一个像那样的。请试试这个：

       var query = (from p in db.Products
                     join o in db.OrderDetails on p.ProductID equals o.ProductID into orderTemp
                     select new type
                     {
                       Product_id = p.Product_id,
                       //set product attribtes,
                       OrderDetail_id = orderTemp.OrderDetail_id,
                       Quantity = orderTemp.Quantity,
                       // set OrderDetail attributtes

                     }.OrderBy(l => l.Quantity.Count()).ToList();

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你尝试过什么，没有得到什么？PS：你的查询看起来很混乱。你有任何与你想要的内容等价的sql语句吗？

       var query = (from p in db.Products
                     join o in db.OrderDetails on p.ProductID equals o.ProductID into orderTemp
                     select new type
                     {
                       Product_id = p.Product_id,
                       //set product attribtes,
                       OrderDetail_id = orderTemp.OrderDetail_id,
                       Quantity = orderTemp.Quantity,
                       // set OrderDetail attributtes

                     }.OrderBy(l => l.Quantity.Count()).ToList();