Question

我正在尝试排除a.id中存在db.AdminAdjusterStatus的项目。

from u in db.Users
join a in db.Adjusters on u.id equals a.userID
where u.userType.ToLower() == "adjuster"
   && !(from x in db.AdminAdjusterStatus select x.adjusterID).Contains(a.id)
select new AdjusterProfileStatusItem { user = u, adjuster = a }

上面的代码中写着“a.id中不包含db.AdminAdjusterStatus.adjusterID的内容。

问题是，它不起作用。我在db.AdminAdjusterStatus中有这两个条目：

A9EC05B5-651D-4AA7-8275-1F6BFE212C03
1BDE55D9-ED0A-4854-9D5F-B89DB17F02D2

然后，LINQ查询给了我：

A9EC05B5-651D-4AA7-8275-1F6BFE212C03
1BDE55D9-ED0A-4854-9D5F-B89DB17F02D2
e21ff49c-9505-495d-b4a3-c259ee3459d6

然而，它应该只给我：

e21ff49c-9505-495d-b4a3-c259ee3459d6

Answer 1

var query = from u in db.Users
             from a in db.Adjusters                         
             where u.userType.ToLower() == "adjuster" && 
             u.id == a.userID && 
             !db.AdminAdjusterStatus.Any(i => i.adjusterID == a.id)

...

Answer 2

您可以尝试对空记录执行左连接和过滤。没有数据进行测试我无法确定是否可以“开箱即用”，但我已经多次使用以下代码进行这样的过滤：

db.Users.Join(db.Abjusters, outer => outer.id, inner => inner.userID, new { User = outer, Adjuster = inner })
    .GroupJoin(DBConcurrencyException.AdminAdjusterStatus, outer => outer.Adjuster.id, inner => inner.adjusterID, new { User = outer.User, Adjuster = outer.Adjuster, Admins = inner })
    .SelectMany(grp => grp.Admins.DefaultIfEmpty(), (grp, admin) => new { User = grp.User, Adjuster = grp.Adjuster, Admin = admin })
    .Where(item => item.User.userType == "adjuster" && item.Admin == null)
    .Select(item => new AdjusterProfileStatusItem { user = item.User, adjuster = item.Adjuster });

GroupJoin / SelectMany组合执行左连接，然后您可以过滤对象为空的位置，该位置应该与NOT IN相同。

Answer 3

感谢大家的帮助，对不起浪费任何人的时间。我意识到这一行：

obj.adjusterID = '@(Url.RequestContext.RouteData.Values["id"])';

我的代码中的其他地方一直在发送u.id而不是a.id，因为我认为它是。因此，我在数据库中保存了错误的ID，从而导致了我遇到的问题。

再次感谢您的帮助！

Answer 4

也许这可行吗？

            var AdjusterItems = from aa in AdminAdjusterStatus
                            join a in Adjusters
                            on aa.AdjusterId equals a.AdjusterId
                            select a.UserId;

        var UsersNotAdjustAdmin = from u in Users
                                  where !AdjusterItems.Any(x => x == u.Id)
                                  && u.UserType.Equals("Adjuster", StringComparison.InvariantCultureIgnoreCase)
                                  select u;

        var result = from u in UsersNotAdjustAdmin
                     join a in Adjusters
                     on u.Id equals a.UserId
                     select new AdjusterProfileStatusItem() { Adjuster = a, User = u };

LINQ＆＃34;不在＆＃34;不工作

4 个答案: