Question

要指定我想要的内容，这是应该完成工作的SQL查询：

             SELECT user
             FROM User AS user
             JOIN UserAssignment AS userAssignment ON userAssignment.UserID = user.ID
             JOIN GroupAssignment AS groupAssignment ON user.ASSIGNMENT_ID = groupAssignment.Id     ---> this is what I can't do in LINQ, because the database columns don't align with the POCO properties (db: user has the association, POCO: groupAssignment has the association)
             WHERE groupAssignment.ClientSIte == \*theGivenClientsite*\ || 
             WHERE userAssignment.ClientSIte == \*theGivenClientsite*\

现在我想要的不是SQL字符串，而是类型安全。在大多数情况下，我一直在使用LINQ to NHibernate，因为它非常相似。

问题在于第4行：加入GroupAssignment ....

在我的数据库中，groupAssignment和用户之间的关联位于用户：user表有一个ASSIGNMENT_ID列。
在c＃代码中（在POCO中，我猜你称之为？），关联在于groupAssignment。 GroupAssignment对象具有属性，即User对象列表。

这意味着，如果我使用LINQ to NHibernate，我必须在包含user的groupAssignment.Users上加入用户和组分配。

这就是我被困的地方。这就是我尝试的内容（注释掉的位是我单独尝试的东西，两者都没有用）：

                List <User> users = (List<User>)
                (from user in session.Query<User>()
                 join userAssignment in session.Query<UserAssignment>() on user equals userAssignment.User
                 join groupAssignment in session.Query<GroupAssignment>() on //user equals groupAssignment.Users.First(u => u.Equals(user))
                 //where groupAssignment.Users.Any(u => u.Equals(user)) &&
                       groupAssignment.ClientSite == clientSite ||
                       userAssignment.ClientSite == clientSite
                 select user
                 ).ToList();

有人可以帮忙吗？使用QueryOver（）或其他任何不仅仅是SQL字符串的解决方案将不胜感激！

编辑：这是我顽固的解决方案：

                IList<UserInfo> usersViaGroupAssignment = (IList<UserInfo>)
                session.Query<GroupAssignment>()
                            .Where(ga => ga.ClientSite.Equals(clientSite))
                            .Select(ga => ga.Users)
                            .SelectMany(x => x).ToList();

            IList<UserInfo> usersViaUserAssignment = (IList<UserInfo>)
                session.Query<UserAssignment>()
                            .Where(ua => ua.ClientSite.Equals(clientSite))
                            .Select(ua => ua.User)
                            .ToList();

            // This removing of duplicates might be inefficient if there is a large amount of assignments concerning the same users.
            List<UserInfo> allUsers = usersViaGroupAssignment.Concat(usersViaUserAssignment).Distinct().ToList();

Linq to NHibernate：在包含该子节点的父节点上使用父表连接子表

0 个答案: