將SQL查詢轉換爲linq查詢表達式

Question

我有一個SQL查詢，我試圖轉換成C＃中的LINQ查詢表達式，但我無法正確執行。

查詢如下：

select 
    P.id, P.name, COUNT(S.orderqty) 
from 
    product as P 
inner join 
    sales as S on P.id = S.id 
group by 
    p.id, p.name 

我的LINQ代碼：

IQueryable<ReportType1> query = 
    from product in EngineContext.Products 
    join SalesOrder inEngineContext.SalesOrderDetails 
    on product.ProductID equals SalesOrder.ProductID 
    group SalesOrder.OrderQty by product into groups 
    select new ReportType1() {  
     Year = null, 
     ProducId = groups.Key.ProductID, 
     Name = groups.Key.Name, 
     Quantity = ?? 
    }; 

怎麼寫的Quantity價值？組的

Answer 1

Count方法：

select new ReportType1 
{ 
    Year = null, 
    ProducId = groups.Key.ProductID, 
    Name = groups.Key.Name, 
    Quantity = groups.Count() 
}