试图在Linq中做一个子查询...有问题！

Question

我想转换我的一些存储过程LINQ和我遇到了下列Transact-SQL语句的问题：

Select 
    Year(p.StartDate) As Year, 
    (Select Sum(t.Units) From Time t Where Year(t.TransactionDate) = Year(p.StartDate)) As Hours, 
    (Select Sum(i.Price) From Invoice i Where Year(i.CreatedDate) = Year(p.StartDate)) As Invoices 
From 
    Period p 
Group By 
    Year(p.StartDate) 
Order By 
    Year(p.StartDate) 

我与LinqPad工作，试图想出解决办法...任何帮助将不胜感激！

进展

我有以下的那么远，只是想弄清楚如何将子查询转换：

from p in Periods 
group p by p.StartDate.Year into g 
orderby g.Key 
select new 
{ 
    g.Key, 
} 

Answer 1

尝试：

from p in Periods 
group p by p.StartDate.Year into g 
orderby g.Key 
select new 
{ 
g.Key, 
Hours = (from t in Times where t.TransactionDate.Year == g.Key select t).Sum(t => t.Units), 
Invoices = (from i in Invoices where i.CreatedDate.Year == g.Key select i).Sum(i => i.Price) 
}