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"))
