相关疑难解决方法(0)

public class ConsolidatedChild
{
    public string School { get; set; }
    public string Friend { get; set; }
    public string FavoriteColor { get; set; }
    public List<Child> Children { get; set; }
}

public class Child
{
    public string School { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
    public string Friend { get; set; }
    public string Mother { get; set; }
    public string FavoriteColor { get; set; }
} …

我正在试验Linq并且无法搞清楚分组.我已经完成了几个教程,但由于某种原因无法弄清楚这一点.

例如,假设我有一个包含多个网站ID的表(SiteStats),该表存储了按类型访问每个网站的访问者总数和过去30天的计数.

????????????????????????????????????????
? SiteId ? VisitorType ? Last30 ? Total?
????????????????????????????????????????
?      1 ?           1 ?     10 ?  100 ?
?      1 ?           2 ?     40 ?  140 ?
?      2 ?           1 ?     20 ?  180 ?
????????????????????????????????????????

在SQL中,我可以使用以下内容轻松获取SiteID 1的计数:

SELECT SiteId,  
       SUM(Last30) AS Last30Sum  
FROM Sites  
WHERE SiteId = 1  
GROUP BY SiteId

并且应该排成一排......

???????????????????????
? SiteId ? Last30Total?
???????????????????????
?      1 ?         50 ?
???????????????????????

但是我不确定如何使用Linq获得此结果.我试过了:

var statsRecord = from ss in db.SiteStats  
    where ss.SiteId == …