Linq To SQL并有

Question

我对Linq To SQL相当新，但试图运行一个相当简单的SQL查询，并且无法弄清楚如何使它在LINQ中表现良好。

SELECT  Users.Id, Users.Id AS Expr1, Users.FirstName, Users.LastName, 
User_x_Territory.UserID 
FROM   Users LEFT OUTER JOIN 
      User_x_Territory ON User_x_Territory.UserID = Users.Id 
GROUP BY Users.Id, Users.Id, Users.FirstName, Users.LastName, User_x_Territory.UserID 
HAVING  (COUNT(User_x_Territory.UserID) = 0) 

只是试图让没有领土分配，告诉他们是否有领土是检查user_x_territory gerrund的唯一途径的所有用户。

我能够用它来获取所有用户的我的DB的：

var users = from u in db.Users 
      join uXt in db.User_x_Territories on u equals uXt.User into gerr 
      from users in gerr.DefaultIfEmpty() 
      select users; 

但是从那里我无法弄清楚如何/有细化搜索结果添加组只显示没有地区的用户。

感谢您的任何帮助。

Answer 1

我建议以下解决方案。

db.Users.Where(u => u.User_x_Territories.Count == 0) 

Answer 2

我不知道如何有效的，这是（我猜不是很），但你可以尝试这样的事：

var users = (from u in db.Users 
      join uXt in db.User_x_Territories on u equals uXt.User into gerr 
      from users in gerr.DefaultIfEmpty() 
      select u).Where(u => u.User_x_Territories.Count == 0); 

Answer 3

编辑：嘿，你猜有人打我给它:(

 
from t in db.Users 
join t0 in db.User_x_Territory on new { UserID = t.Id } equals new { UserID = t0.UserID } into t0_join 
from t0 in t0_join.DefaultIfEmpty() 
group new {t, t0} by new { 
    t.Id, 
    Column1 = t.Id, 
    t.FirstName, 
    t.LastName, 
    t0.UserID 
} into g 
where g.Count() == 0 
select new { 
    Id = g.Key.Id, 
    Expr1 = g.Key.Id, 
    g.Key.FirstName, 
    g.Key.LastName, 
    UserID = g.Key.UserID 
}