Linq to Entities EF4

Question

我有一个组域模型name,desc和users(属于该组)的集合

我试图获取特定用户所属的所有组.这是我的LinQ声明:

var results = from p in AuthorizationService.UnitOfWork.Groups.FindAll()
                          where
                              (p.Users != null && p.Users.Select(u => u.Id).Contains(CurrentUser.Id))
                          select p.Name;

我尝试执行查询时收到以下错误

Cannot compare elements of type 'System.Collections.Generic.ICollection`1'. Only primitive types (such as Int32, String, and Guid) and entity types are supported.

任何帮助表示赞赏.谢谢!

Answer 1

删除Users对象的null测试,无论如何它是延迟加载的,你的用户是虚拟的吗？如果是,它是延迟加载的,那么可以删除null测试

var results = 
from p in AuthorizationService.UnitOfWork.Groups.FindAll() 
where 
     p.Users.Any(u => u.Id == CurrentUser.Id)
select p.Name;