在代码中,注释部分是我需要解决的问题…有没有办法在LINQ中编写这样的查询？我需要这个,因为我需要根据状态进行排序.
var result = (
from contact in db.Contacts
join user in db.Users on contact.CreatedByUserID equals user.UserID
join deal in db.Deals on contact.ContactID equals deal.ContactID into deals
orderby contact.ContactID descending
select new ContactListView
{
ContactID = contact.ContactID,FirstName = contact.FirstName,LastName = contact.LastName,Email = contact.Email,Deals = deals.Count(),EstValue = deals.Sum(e => e.EstValue),SalesAgent = user.FirstName + " " + user.LastName,Tasks = 7,// This is critical part
if(Deals == 0) Status = "Prospect";
else
Status = "Client";
// End of critical part...
})
.OrderBy(filterQuery.OrderBy + " " + filterQuery.OrderType)
.Where(filterQuery.Status);
解决方法
Status = (deals.Count() == 0 ? "Prospect" : "Client")
The conditional operator (?:) returns
one of two values depending on the
value of a Boolean expression.
编辑：你可以像这样组合：
Status = (deals.Count() == 0 ? "Prospect" : (deals.Count() == 1 ? "Client" : "Other"))
在这种情况下,您正在使用deals.Count(),因此您可以使用LINQ let语法将结果存储在临时变量中：
var result = (
from contact in db.Contacts
join user in db.Users on contact.CreatedByUserID equals user.UserID
join deal in db.Deals on contact.ContactID equals deal.ContactID into deals
let dealCount = deals.Count()
... // Continue here
Status = (dealCount == 0 ? "Prospect" : (dealCount == 1 ? "Client" : "Other"))
