我在将这段代码转换成扩展方法语法时遇到了一些麻烦:
var query = from c in _context.Customers
from o in c.Orders
where o.DateSent == null
select new CustomerSummary
{
Id = c.Id,
Username = c.Username,
OutstandingOrderCount = c.Orders.Count
};
有什么想法吗?